|
|
|
|
|
| Mycorrhiza, 2002 Jun, 12(3), 147 - 51 Epub 2002 Mar 27. Ectomycorrhizal root development in wet Alder carr forests in response to desiccation and eutrophication; Baar J et al.; Effects of desiccation and eutrophication on ectomycorrhizal (ECM) root development in wet Alder carr forests in The Netherlands were studied . In northwestern Europe, wet Alder carr forests are found mostly in peatlands and along streams, forming an important component of wetland ecosystems . The dominant tree species in wet Alder carr forests is Alnus glutinosa (L.) Gaertn . (Black alder), which associates with ectomycorrhizal fungi . During recent decades, wet Alder carr forests in Europe have declined because of desiccation and eutrophication, particularly in The Netherlands . In the present study, the number of root tips of A . glutinosa trees was highest in an undisturbed wet Alder carr forest in a peatland area . Eutrophication in the peatland area significantly inhibited ectomycorrhizal (ECM) root development of A . glutinosa . In the eutrophied forest, ECM root tips were observed only close to A . glutinosa trees growing on hummocks . The concentrations of nitrate and potassium in soil water of the eutrophied forest were significantly higher than in the undisturbed forest, while magnesium and iron concentrations and the pH were significantly lower . The number of ECM root tips of A . glutinosa in a desiccated forest along a stream was generally lower than in an undisturbed wet Alder carr forest on waterlogged soil in the same area . The sulphate concentration in soil water in the desiccated forest was significantly higher than in the forest on waterlogged soil . ECM root development of A . glutinosa may have been negatively affected by the chemical composition of the soil water. Braz J Biol, 2001 Nov, 61(4), 523 - 40 Epub 2002 May 24. Association of periphytic diatom species of artificial substrate in lotic environments in the Arroio Sampaio Basin, RS, Brazil: relationships with abiotic variables; Oliveira MA et al.; Associations of diatom species were identified, in the Arroio Sampaio Basin, Rio Grande do Sul, Brazil, based on monthly samplings over a year along Arroio Sampaio and its main tributaries, using polyamide thread as an artificial substrate . The species groupings showed four different environments: medium-lower course of Arroio Sampaio; and lower course of Arroio Teresinha; upper course of Arroio Sampaio; and lower course of Arroio Duvidosa . Among the physical and chemical variables measured, water pollution, particularly organic contamination and eutrophication, measured from BOD, and total phosphate concentration, respectively, appeared to be one of the most important environmental factors determining the composition and structure of species associations in the area studied. Parazitologiia, 2002 Mar-Apr, 36(2), 140 - 5 {Ectoparasite infection of some fish species in lake Pleshcheev}; Zharikova TI et al.; Ectoparasites have been investigated on gills of the ruff, perch, white bream, roach, bream, ide, and European cisco from the Pleshcheevo lake . 13 parasite species were found: Dactylogyrus falcatus, D . distinguendus, D . cornoides, D . cornu, D . sphyrna, D . robustus, D . amphibothrium, Ancyrocephalus paradoxus, Argulus foliaceus, Ergasilus sieboldi, Achtheres percarum, Ancyrocephalus percae, and Rhipidocotyle companula . A reliable negative correlation between the number of monogeneans An . paradoxus and the copepods Ac . percarum on the perch . D . falcatus, the specific monogenean of the bream, was found on the roach . The comparison of the obtained data with those of 1939 has shown the decrease of oxyphilic copepods E . seiboldi, that prove the increasing eutrophication. Environ Toxicol Chem, 2002 Jun, 21(6), 1219 - 28 Bioavailability of metals to the amphipod Monoporeia affinis: interactions with authigenic sulfides in urban brackish-water and freshwater sediments; Wiklund AK et al.; Could reduced eutrophication be a potential environmental threat because of increased mobility and bioavailability of trace metals? This question was addressed by oxygenating intact sediment cores, varying in redox potential and salinity, in a test system containing the amphipod Monoporeia affinis . Results show a low mobility of metals during oxygenation, and despite high concentrations of metals in sediments, only Pb showed a notable degree of bioaccumulation . Cadmium was bioaccumulated particularly in freshwater sediment, and body burden of Cd was related to salinity, porewater, and sediment concentrations . Despite high sediment and porewater concentrations of Cu and Zn, no relationship was recorded to body burden . For three of four tested metals, Cd, Pb, and Zn, metals in sediment were more important for body burdens in amphipods as compared to metals in porewater . Food, rather than interstitial water, therefore seems to be the main route of metal contaminants to these amphipods . Furthermore, this observed low release of metals from sediments and low body burden significance of porewater metals indicate that ameliorated oxygen conditions in contaminated sediments may be regarded as a minor environmental threat for one of the most important Baltic benthic organisms. Mar Environ Res, 2002 Jun, 53(5), 465 - 79 Reed (Phragmites australis) decline in a brackish wetland in Italy; Fogli S et al.; A comparative field study was carried out at two sites (a healthy site and a declining site) in a brackish wetland in northern Italy, with the objective to investigate the symptoms and the possible causes leading to reed (Phragmites australis) decline in this area . The declining reed plants presented many of the symptoms (clumping habit, smaller size, weaker culms, abnormal rhizome and root anatomy, low starch levels in rhizomes) comprised within the so-called reed die-back syndrome, frequently observed in central European wetlands but never recorded previously in (Sub)Mediterranean regions . Soil nutrient levels did not differ much between the two sites, with nitrate concentrations in the soil being even higher at the healthy site (1.54 microg g(-1); die-back site 0.76 microg g(-1)) . Hence, eutrophication did not seem to represent a major cause in determining reed decline in this area . High sulphate concentrations in saltwater associated with low soil redox potentials (-215 mV) due to waterlogging resulted in high soil sulphide concentrations . Concentrations of organic acids, especially acetic acid, did not differ remarkably between sites . High sulphide levels presumably accounted for abnormal anatomical formations (callus blocking aerenchyma channels), lower rates of net CO2 exchange and reduced reserve storage, observed at the die-back site . This was associated with a lower mechanical resistance of reed culms which accelerated reed mortality in the die-back areas . We concluded that high sulpihde levels in permanently waterlogged soils may result in die-back of reed stands in Mediterranean wetlands. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002, 37(5), 913 - 24 In situ experimental evidence of phosphorus limitation on algal growth in a lake ecosystem; An KG et al.; This paper presents the results of in situ Nutrient Stimulation Experiments (NSEs) demonstrating that phosphorus was the primary nutrient controlling algal growth in the Taechung Reservoir, Korea . Algal response in most treatments with only nitrogen added was less than or the same as in the controls, whereas the growth in treatments enriched with phosphorus increased by as much as fivefold . Phosphorus limitation was consistent over the experimental period when bioassay experiments were conducted, but the magnitude of growth response to phosphorus enrichments varied with the season . Algal yield in P-treatments was maximum when thermal stratification was strong and total dissolved phosphorus (TDP) was near the level of depletion . Regression analyses of NSEs showed that in situ algal response in P treatments, measured as log-transformed CHLf:CHLi ratios, declined (R2 = 0.995, p < 0.001) with ambient concentrations of log-transformed TDP . Also, algal response in the P treatments showed a first-order linear fit (R2 = 0.961, p < 0.001) with log-transformed DIN (dissolved inorganic nitrogen):TDP ratios . These outcomes indicate that the magnitude of in situ algal response increased with lower levels of P and higher dissolved N:P ratios in the ambient lake water . Our experimental approach employing NSEs suggests that abatement of phosphorus from the watershed seems to be an efficient management strategy to control the eutrophication of this system. J Environ Sci (China), 2002 Apr, 14(2), 255 - 63 History, development and characteristics of lake ecological models; Xu FL et al.; This paper provides some introductory information on the history, development, and characteristics of various lake ecosystem models . The modeling of lake ecological processes began to gain importance in the early 1960s . There are a number of models available today, with varying levels of complexity to cope with the variety of environmental problems found in lake environments, e.g . eutrophication, acidification, oxygen depletion, wetland management, heavy metal and pesticide pollution, as well as hydrodynamic problems . In particular, this paper focuses on lake eutrophication and wetland models, as well as addressing strategies appropriate for the design and development of reliable lake ecological models. Environ Sci Technol, 2002 May 15, 36(10), 2109 - 15 Predicting the frequency of water quality standard violations: a probabilistic approach for TMDL development; Borsuk ME et al.; To address the impaired condition of the water bodies listed under Section 303(d) of the Clean Water Act, over 40 000 total maximum daily loads (TMDLs) for pollutants must be developed during the next 10-15 years . Most of these will be based on the results of water quality simulation models . However, the failure of most models to incorporate residual variability and parameter uncertainty in their predictions makes them unsuitable for TMDL development . The percentile-based standards increasingly used by the EPA and the requirement for a margin of safety in TMDLs necessitate that model predictions include quantitative information on uncertainty . We describe a probabilistic approach to model-based TMDL assessment that addresses this issue and is suitable for use with any type of mathematical model . To demonstrate our approach, we employ a eutrophication model for the Neuse River Estuary, North Carolina, and evaluate compliance with the state chlorophyll a standard . Any observed variability in chlorophyll athatis notexplained bythe model is explicitly incorporated via a residual error term . This probabilistic term captures the effects of any processes that are not considered in the model and allows for direct assessment of the frequency of standard violations . Additionally, by estimating and propagating the effects of parameter uncertainty on model predictions, we are able to provide an explicit basis for choosing a TMDL that includes a margin of safety . We conclude by discussing the potential for models currently supported by the EPA to be adapted to provide the type of probabilistic information that is necessary to support TMDL decisions. Philos Trans R Soc Lond B Biol Sci, 2002 Apr 29, 357(1420), 449 - 69 Inositol phosphates in the environment; Turner BL et al.; The inositol phosphates are a group of organic phosphorus compounds found widely in the natural environment, but that represent the greatest gap in our understanding of the global phosphorus cycle . They exist as inositols in various states of phosphorylation (bound to between one and six phosphate groups) and isomeric forms (e.g . myo, D-chiro, scyllo, neo), although myo-inositol hexakisphosphate is by far the most prevalent form in nature . In terrestrial environments, inositol phosphates are principally derived from plants and accumulate in soils to become the dominant class of organic phosphorus compounds . Inositol phosphates are also present in large amounts in aquatic environments, where they may contribute to eutrophication . Despite the prevalence of inositol phosphates in the environment, their cycling, mobility and bioavailability are poorly understood . This is largely related to analytical difficulties associated with the extraction, separation and detection of inositol phosphates in environmental samples . This review summarizes the current knowledge of inositol phosphates in the environment and the analytical techniques currently available for their detection in environmental samples . Recent advances in technology, such as the development of suitable chromatographic and capillary electrophoresis separation techniques, should help to elucidate some of the more pertinent questions regarding inositol phosphates in the natural environment. Environ Pollut, 2002, 118(3), 351 - 5 Tolerance to, and avoidance of, hypoxia by the penaeid shrimp (Metapenaeus ensis); Wu RS et al.; Aquatic hypoxia caused by eutrophication may lead to mass mortality of valuable living resources such as fish and shrimp . However, there is little information on the hypoxic tolerance of penaeid shrimp, and whether they are able to avoid hypoxia . In laboratory experiments, LC50, LT50 and heart beats per minute were determined for juvenile Metapenaeus ensis at 0.5, 1.0, 2.0 and 6.0 mg O2 l(-1) . The 8-h LC50, for DO was 0.77 mg O2 l(-1), while the LT50 at 0.5 mg O2 l(-1) was 399 min . Heart beat rate significantly declined when DO fell below 1.0 mg O2 l(-1) . When confronted with a gradient of dissolved oxygen, M . ensis were able to avoid hypoxic areas and move to oxygenated water . M . ensis appeared to be sensitive to hypoxia, and their ability to detect and avoid hypoxia may enhance their survival in habitats where hypoxia may occur. J Environ Manage, 2002 Feb, 64(2), 99 - 113 Geographic information system based manure application plan; Basnet BB et al.; A geographic information system (GIS) based manure application plan has been developed for the site-specific application of animal waste to agricultural fields in the Westbrook sub-catchment of the Murray-Darling Basin, south-east Queensland, Australia . Sites suitable for animal waste application were identified using a GIS based weighted linear combination (WLC) model . The degree of land suitability for animal waste application was determined using a range of social, economic, environmental, and agricultural factors . As eutrophication and toxic blue-green algae blooms are a known problem in the catchment, the manure application rates were limited to the rate of crop phosphorus removal . Maximum manure application rate was calculated spatially by taking the crop nutrient (P2O5) requirement and the manure nutrient (P2O5) content into account . The environmental suitability of the fields receiving animal waste was considered in prescribing the final application rate of solid and liquid manures generated by local animal production facilities . The degree of site suitability of the agricultural fields was also used to suggest manure management practices to minimise the socio-environmental risks and increase the nutrient use efficiency of the applied manure . The amount of ammonium nitrogen (NH4-N) that would be added to the soil by satisfying the P2O5 requirement using manure sources was also calculated and an applied NH4-N map was created . This map could be used to assist farmers identify additional nitrogen requirements after manure application. Sci Total Environ, 2002 Apr 15, 288(3), 167 - 81 Biological and chemical factors influencing shallow lake eutrophication: a long-term study; Lau SS et al.; The focus of eutrophication research has tended to be upon short-term and experimental studies . However, given the range of factors that can influence eutrophication dynamics, and that these matter over a range of time scales, some discrete, some continuous, eutrophication dynamics may only be fully investigated when long-term, time-series data are available . The present study aims to evaluate the interacting effects of abiotic processes and biotic dynamics in explaining variations of phytoplankton biomass in a eutrophic shallow lake, Barton Broad (Norfolk, UK) using a long-term data set . Multivariate statistical analysis shows that the inter-relationships between phytoplankton variability, nutrient and grazing factors were highly sensitive to seasonal periodicity . In spring phytoplankton biomass was related to phosphorus, nitrogen and silicon . In summer phytoplankton biomass was associated with phosphorus, nitrogen and zooplankton . In autumn phytoplankton was related to phosphorus, nitrogen, silicon and zooplankton . In winter, no significant relationship could be established between phytoplankton and environmental variables . This paper improves our understanding of the governing role of nitrogen, phosphorus, silicon and zooplankton upon phytoplankton variability, and hence, improves management methods for eutrophic lakes. Wei Sheng Yan Jiu, 1999 Mar 30, 28(2), 100 - 1 {Study on the contamination of algae and microcystins in water sources of Zhengzhou City}; Meng Y et al.; Planktonic algae and microcystins (MCYST) were detected constantly in water sources of Zhengzhou City from 1996 to 1997 . There is significant seasonal variation of the density of algae . The peak of algae occurring in February and December is about 1,068,000/L . The contents of MCYST in July, 1995 and in January, 1996 were over 200 ng/L . According to the Carlson's trophic state index(TSI), and indexes of total nitrogen, phosphorus, COD value and algae density, an eutrophication of water source having emerged in Zhengzhou is considered. Trends Plant Sci, 2002 Mar, 7(3), 118 - 25 Engineering crop plants: getting a handle on phosphate; Brinch-Pedersen H et al.; In plant seeds, most of the phosphate is in the form of phytic acid . Phytic acid is largely indigestible by monogastric animals and is the single most important factor hindering the uptake of a range of minerals . Engineering crop plants to produce a heterologous phytase improves phosphate bioavailability and reduces phytic acid excretion . This reduces the phosphate load on agricultural ecosystems and thereby alleviates eutrophication of the aquatic environment . Improved phosphate availability also reduces the need to add inorganic phosphate, a non-renewable resource . Iron and zinc uptake might be improved, which is significant for human nutrition in developing countries. J Environ Sci (China), 2002 Jan, 14(1), 76 - 8 Assessment of water pollution control strategies: a case study for the Dianchi Lake; Chen JN et al.; Lake eutrophication has increasingly become a major environmental issue in China . Although significant efforts have been made towards its resolution in the last decade, most of the implemented control strategies are fragmented, and the formation of policy lacks of sound scientific basis and long-term objectives . Taking the well-known Dianchi Lake as a case study, this paper presented a comprehensive assessment for the effectiveness of various eutrophication control strategies . It is expected that the concluding lessons would have a major implication to future eutrophication control. J Environ Sci (China), 2002 Jan, 14(1), 54 - 62 Cyanobacterial flora and the physico-chemical environment of six tropical fresh water lakes of Udaipur, India; Pandey J et al.; The cyanobacteria and physico-chemical environments of six tropical fresh water lakes of Udaipur, India were investigated . These lakes receive varying nutrient inputs from different sources . Altogether 51 species of cyanobacteria were recorded . Species composition varied between lakes and between seasons . Lake VI (Baghdara), which receives nutrients from natural sources only, differed considerably from the others in water chemistry and composition of dominant species . Lake II (Swaroop Sagar), eutrophied due to sewage inputs, was species poor . Non-diazotrophs, represented by 27 species, dominated during summer . With few exceptions, N2-fixing species, both heterocystous and unicellular diazotrophs (represented by 24 species), were dominant during winter . Microcystis aeruginosa, Phormidium sp . and Anabaena flos-aque were the dominant taxa of lakes characterized by sewage eutrophication . The study shows that both species diversity and community composition were affected by water chemistry. Environ Sci Technol, 2002 Feb 15, 36(4), 552 - 60 Emission inventories of NOx from commercial energy consumption in China, 1995-1998; Hao J et al.; Emissions of nitrogen oxides (NOx) in China are of great concern because of their impact on local air pollution as well as on regional environmental risks such as acid rain, eutrophication, tropospheric ozone, fine particulate matter, and loss of biodiversity . In this paper, total anthropogenic emissions of NOx in China during the past two decades are estimated on the basis of commercial energy consumption and NOx emission factors of different sectors and fuel types . Specifically, emission inventories of NOx from 31 provinces, 7 economic sectors, and 11 fuel types from 1995 to 1998 are evaluated and analyzed in detail, and the distribution of provincial-based average NOx emission intensity in 1998 is presented . It can be seen that the calculated national total emissions of NOx have rapidly increased from 4.76 Mt in 1980 to a peak value of about 12.03 Mt in 1996, with an average annual growth rate of 6% . However, instead of increasing, NOx emissions in 1997 and 1998 decreased by 0.37 Mt and 0.85 Mt, respectively, as compared to the peak in 1996 . In short, NOx emissions caused by energy use are mainly concentrated in the more populated and industrialized areas of China, i.e., the Eastern Central and Southeastern areas . These results imply that China's NOx emissions in the future may not become as high as previously expected which will be helpful for policy making to control local NOx pollution as well as to reduce acid rain and tropospheric ozone in East Asia. Sci Total Environ, 2002 Feb 21, 285(1-3), 97 - 105 Rapid assessment of macro algal cover on intertidal sediments in a nutrified estuary; Nedwell DB et al.; Macroalgal blooms have been considered to be an indicator of eutrophication . A new and rapid method is described for the assessment of macroalgal cover in the intertidal zone of estuaries . Macroalgal cover in the intertidal of the nutrient-enriched River Deben estuary was found to reach a maximum of 50% coverage, but this varied seasonally with the highest percentage cover during June and July . Macro-algae mats were particularly associated with areas of hard substrata providing suitable attachment points, rather than with the nutrient concentrations along the estuary . The occurrence of macroalgae may be more related to the substrate than to the nutrient status of the estuary. Ambio, 2001 Dec, 30(8), 522 - 8 Human impact on the fish diversity in the four largest lakes of Sweden; Degerman E et al.; The four largest Swedish lakes, Vanern, Vattern, Malaren, Hjalmaren, host important commercial fisheries for char, salmon, trout, whitefish, vendace (cisco), perch, pike-perch, pike and eel, i.e . highly diverse biological resources . Case studies illustrate physical, chemical and biological impacts on some of these commercial species caused by constructions of dams and ship canals, eutrophication, and overexploitation . Although some original species have been lost and a few new species have been added, the recent human interference has basically caused major shifts in dominance of the fish community structures because of eutrophication, alterations in the abundance of eel or crayfish, and due to overfishing . The latter is in some cases caused by the Great Lake Fishery Paradox--in an environment with several predators and competitors, but with ample food resources, especially salmonid fish but also species like pike-perch may adapt a life history favoring growth over sexual maturation . If harvested at a conventional size these populations will decline rapidly due to too small spawning stocks. Ambio, 2001 Dec, 30(8), 496 - 502 Sediment evidence of early eutrophication and heavy metal pollution of Lake Mälaren, central Sweden; Renberg I et al.; Lake Malaren is the water supply and recreation area for more than 1 million people in central Sweden and subject to considerable environmental concern . To establish background data for assessments of contemporary levels of trophy and heavy metal pollution, sediment cores from the lake were analyzed . Diatom-inferred lake-water phosphorus concentrations suggest that pre-20th century nutrient levels in Sodra Bjorkfjarden, a basin in the eastern part of Malaren, were higher (c . 10-20 micrograms TP L-1) than previously assumed (c . 6 micrograms TP L-1) . Stable lead isotope and lead concentration analyses from 3 basins (S . Bjorkfjarden, Gisselfjarden and Askofjarden) show that the lake was polluted in the 19th century and earlier from extensive metal production and processing in the catchment, particularly in the Bergslagen region . The lake has experienced a substantial improvement of the lead pollution situation in the 20th century following closure of the mining and metal industry . The lead pollution from the old mining industry was large compared to late-20th century pollution from car emissions, burning of fossil fuels and modern industries. Ambio, 2001 Dec, 30(8), 475 - 85 Recovery from eutrophication: experiences of reduced phosphorus input to the four largest lakes of Sweden; Wilander A et al.; In-lake concentration changes of phosphorus (P) and nitrogen (N) in lakes Vattern, Vanern, Malaren, and Hjalmaren in response to diminished input has been examined from the mid-1960s onwards . In the former two deep and oligotrophic lakes with slow water renewal, drastic reductions in P-input from the middle of 1970s caused just minor reductions in P-concentration over a very long time . At the same time accumulation occurred in the water mass of inorganic N and possible reasons are discussed . In the latter two mesotrophic to hypertrophic lakes, two shallow basins in L . Hjalmaren showed slow recovery due to release of P from sediments . The same basins and two basins in L . Malaren have suffered from N-deficiency, particularly during the pre-phosphorus reduction years, and nitrogen fixation was indicated . In two L . Malaren basins recovery of in-lake P concentrations was better than expected in comparison to the so-called IMSA-model for lake recovery from nutrient pollution . In the other five lakes/basins chlorophyll concentrations after 20 years were similar compared to those modeled. Zh Obshch Biol, 2001 Nov-Dec, 62(6), 512 - 24 {Structure and function of pelagic zooplankton in various types of lakes (using the example of small lakes in northwestern Russia}; Ivanova MB; Changes of structure and functioning of pelagic zooplankton under lake eutrophication were studied in a group of small (without outlet) lakes in southern Karelia and Leningrad region . The lakes were morphologically similar and located within the same climatic zone . Differences in their trophic status were connected with anthropogenic eutrophication . Correlation between species number and feeding resources of a lake is determined as: Y = (8.01 +/- 3.85) + (0.29 +/- 0.07)X1 + (6.75 +/- 1.52)X2, r2 = 0.95, (1) Y--number of zooplankton species, X1--average chlorophyll concentration for the season, mg/1; X2--average value of biochemical oxygen demand (expressed in mgC/1) . Average biomass of zooplankton for season also depends on food: logY = (-0.054 +/- 0.224) + (0.242 +/- 0.094)logX1 + (0.170 +/- 0.179)logX2, n = 13, r2 = 0.87, (2) Y--average zooplankton biomass for the season, kcal/m3, X1 and X2 the same as (1) . Increase in species number and zooplankton bimass determined primarily by Rotatoria occur in parallel to chlorophyll concentration and activity of bacteria . In acid lakes rotifers are not important in energy balance . In mezotrophic lakes two main energy paths are formed--through rotifers and through Crustacea . The role of rotifers is extremely important in eutrophic lakes where about 80% of energy paths through them . The ratio community production to energy consumption for the growing season is also depended on the community structure (species number, equitability, connectence): Y = (2.257 +/- 0.026) - (0.368 +/- 0.031)X1 + (5.160 +/- 0.442)X2, r2 = 0.99, (3) Y--average seasonal production of zooplankton, kcal/m2; X1--maximal meaning of Shannon index (bites), calculated on biomass value; X2--connectence of the community, calculated according Briand (1983) . Eutrophication changes the stability of lakes relative to external influences, while low productive lakes are very sensitive to the increase in nutrient load, high productive lakes are more influenced by changes in fish predation. Zhonghua Yu Fang Yi Xue Za Zhi, 2000 Mar, 34(2), 92 - 4 {Studies on algae and microcystin pollution in source water of Yellow River in Zhengzhou city}; Meng Y et al.; OBJECTIVE: To study the law of development of pollution with algae and microcystin (MC) in source water of Yellow River in Zhengzhou city . METHODS: Algae and MC were detected continuously for source water samples collected from B and S Water Works of Zhengzhou in 1998 . Microcystin was determined with high-sensitive ELISA . RESULTS: Monthly average density of algae was 1,439 x 10(4)/L in source water of B Water Works of Zhengzhou, with peak algae density of 4,762 x 10(4)/L in August, and that of S Water Works was 1,071 x 10(4)/L . Blue-algae of higher toxicity has become dominant species in source water from S water Works . Detection rate of microcystin was 70.83% in 24 samples collected from the two water works . CONCLUSION: According to Carlson's trophic state index (TSI), as well as other indices, such as total nitrogen, total phosphorus, chemical oxygen demands (COD) and algae density in water, source water in Zhengzhou has presented characteristics of eutrophication. Bioresour Technol, 2002 Mar, 82(1), 27 - 31 Growth rate of Ulva rigida in different Mediterranean eutrophicated sites; de Casabianca ML et al.; The growth of juvenile populations of Ulva rigida C . Agardh was measured by means of immersion in in situ cages against environmental parameters (temperature, incident light, salinity, dissolved inorganic nitrogen and dissolved reactive phosphorus) in four different eutrophicated southern sites: Channel of the Thau lagoon (France), Lido, Sacca Sessola and Fusina stations (Venice lagoon, Italy) . The growth curves as a function of temperature showed that, in all cases, the maximal temperature for Ulva growth was 17 degrees C (limitation in growth below 7 degrees C and above around 25 degrees C) . The growth analysis of these four sites showed seasonal differences . In the least eutrophicated and calmest Lido station, grazing and dissolved reactive phosphorus (seven times lower at Lido than at Thau) played a key role . At Thau and Fusina, which are eutrophicated and turbid environments, the incident light had a strong impact on growth . Sacca Sessola, with an intermediate position between the above two mentioned situations, showed the highest growth rate . The values and relative growth rate (RGR) curves of the Mediterranean and open-sea northern sites are discussed . In particular, the temperature defines the type of growth curve (unimodal or bimodal) and the incident light is responsible for the low Mediterranean RGR values (<10% day(-1)). Sci Total Environ, 2002 Jan 23, 282-283, 9 - 24 Agricultural nutrient inputs to rivers and groundwaters in the UK: policy, environmental management and research needs; Withers PJ et al.; Losses of nitrogen (N) and phosphorus (P) in land run-off and drainage from agricultural land can impair river water quality and may pose a potential health hazard . Losses of P are up to an order of magnitude smaller than those of N, but may be more significant with respect to freshwater eutrophication . At the field scale, research suggests that rates of nutrient loss are sensitive to both nutrient and land management, in particular, where nutrient inputs continuously exceed production requirements and where farming methods increase land vulnerability to run-off and erosion . A clear distinction can be made between N and P in the timescales over which inputs of these nutrients are buffered by terrestrial ecosystems against loss, which has implications for control strategies . At the river basin scale, any targets for reducing nutrient loss are best guided by site-specific information on their likely ecological impact, but this information rarely exists for UK rivers affected by eutrophication, and only general guidelines are available . True management of the environment requires integrated approaches which include both N and P taking account of differences in their source areas and delivery mechanisms, the vulnerability of land use and adoption of safe management options in relation to landscape characteristics and the sensitivity of the watercourse along its reach . For P, the identification of vulnerable zones represents a step forward to the management of the river basin in smaller definable units, which can provide a focus for safe management practices . This requires a better understanding of the linkages between nutrient sources, transport and impacts and is considered an urgent research priority. Proc R Soc Lond B Biol Sci, 2002 Feb 7, 269(1488), 289 - 94 History and timing of human impact on Lake Victoria, East Africa; Verschuren D et al.; Lake Victoria, the largest tropical lake in the world, suffers from severe eutrophication and the probable extinction of up to half of its 500+ species of endemic cichlid fishes . The continuing degradation of Lake Victoria's ecological functions has serious long-term consequences for the ecosystem services it provides, and may threaten social welfare in the countries bordering its shores . Evaluation of recent ecological changes in the context of aquatic food-web alterations, catchment disturbance and natural ecosystem variability has been hampered by the scarcity of historical monitoring data . Here, we present high-resolution palaeolimnological data, which show that increases in phytoplankton production developed from the 1930s onwards, which parallels human-population growth and agricultural activity in the Lake Victoria drainage basin . Dominance of bloom-forming cyanobacteria since the late 1980s coincided with a relative decline in diatom growth, which can be attributed to the seasonal depletion of dissolved silica resulting from 50 years of enhanced diatom growth and burial . Eutrophication-induced loss of deep-water oxygen started in the early 1960s, and may have contributed to the 1980s collapse of indigenous fish stocks by eliminating suitable habitat for certain deep-water cichlids . Conservation of Lake Victoria as a functioning ecosystem is contingent upon large-scale implementation of improved land-use practices. J Environ Qual, 2002 Jan-Feb, 31(1), 338 - 49 Gas dynamics in eutrophic lake sediments affected by oxygen, nitrate, and sulfate; Liikanen A et al.; In many freshwater ecosystems, the contents of NO3- and SO4(2-) have increased, whereas O2 has been depleted due to the increased acid and nutrient loads . These changes may affect carbon turnover and the dynamics of the major greenhouse gases CO2, CH4, and N2O . We studied the effects of O2, NO3-, and SO4(2-) availability on carbon mineralization, and fluxes of CO2, CH4, and N2O in the sediments of hyper-eutrophic Lake Kevaton, Finland . Undisturbed sediment cores from the deep (9 m) and shallow (4 m) profundal were incubated in a laboratory microcosm with oxic and anoxic water flows with NO3- or SO4(2-) concentrations of 0, 30, 100, 300, and 2000 microM . The carbon mineralization rate (i.e., the sum of released CO2-C and CH4-C) was not affected by the oxidants . However, the oxidants did change the pathways of carbon degradation and the release of CH4 . All of the oxidants depressed CH4 fluxes in the shallow profundal sediments, which had low organic matter content . In the deep profundal sediments rich in organic matter, the CH4 release was reduced by O2 but was not affected by SO4(2-) (the effect of NO3- was not studied) . There was an increase in N2O release as the overlying water NO3- concentration increased . Anoxia and highly elevated NO3- concentrations, associated with eutrophication, increased drastically the global warming potential (GWP) of the sedimentary gases in contrast to the SO4(2-) load, which had only minor effects on the GWP. J Environ Qual, 2002 Jan-Feb, 31(1), 280 - 6 Bioavailable phosphorus in runoff from alfalfa, smooth bromegrass, and alfalfa-smooth bromegrass; Zemenchik RA et al.; Runoff from sloping landscapes cropped with established alfalfa (Medicago sativa L.) may contain bioavailable P (BAP) which accelerates eutrophication of surface water bodies . Such BAP exists as either dissolved reactive P (DRP) or bioavailable reactive particulate P (BPP) . We hypothesized that before and after harvest, sod-forming smooth bromegrass (Bromus inermis Leyss.) or alfalfa-smooth bromegrass mixtures would have less BAP, DRP, and BPP runoff losses than taprooted alfalfa . Swards established in 1992 near Lancaster, WI were subjected to a 72 mm simulated rainfall applied for 1 h in 1993 and 1994 to forage regrowth at 4 and 6 wk after first harvest and immediately (0 wk) after second harvest . Hourly BAP losses for all sward types were 82% less when 1.5 Mg ha(-1) of forage dry matter was present . High DRP losses (>0.050 kg ha(-1)) were associated with high DRP concentrations (>7.1 micromol L(-1)) and high surface soil P concentrations (>59 mg kg(-1)) resulting from broadcast maintenance P fertilizer . High BPP losses (>0.035 kg ha(-1)) were associated with high runoff volumes (>24 mm) and sediment concentrations (>2 g L(-1)) . Summed over all 6 rainfall simulations, total BAP loss was only 0.07 kg ha(-1) at the 6 wk stage of regrowth compared with 0.35 at 4 wk, and 0.41 at 0 wk . Moreover, there was no significant difference between sward types for DRP concentration, DRP loss, or BAP loss . We conclude that avoiding excessive defoliation was more effective at reducing BAP losses than specific forage species selection. Proc Natl Acad Sci U S A, 2002 Feb 5, 99(3), 1395 - 8 Epub 2002 Jan 29. Anthropogenic modification of New England salt marsh landscapes; Bertness MD et al.; Salt marshes play a critical role in the ecology and geology of wave-protected shorelines in the Western Atlantic, but as many as 80% of the marshes that once occurred in New England have already been lost to human development . Here we present data that suggest that the remaining salt marshes in southern New England are being rapidly degraded by shoreline development and eutrophication . On the seaward border of these marshes, nitrogen eutrophication stimulated by local shoreline development is shifting the competitive balance among marsh plants by releasing plants from nutrient competition . This shift is leading to the displacement of natural high marsh plants by low marsh cordgrass . On the terrestrial border of these same marshes, shoreline development is also precipitating the invasion of the common reed, Phragmites, by means of nitrogen eutrophication caused by the removal of the woody vegetation buffer between terrestrial and salt marsh communities . As a consequence of these human impacts, traditional salt marsh plant communities and the plants and animals that are dependent on these habitats are being displaced by monocultures of weedy species. Environ Pollut, 2002, 116(2), 309 - 17 Fish community responses to pulp and paper mill effluents at the southern Lake Saimaa, Finland; Karels AE et al.; The fish community in sublittoral and profundal waters, at stony shores, and densities of vendace larvae were studied in the southern Lake Saimaa, Finland . The objective was to investigate the possible recovery of fish populations after modernizations at the pulp and paper mills discharging into the lake . Sublittoral and profundal waters were studied by gill net trial fishings, stony shores by electrofishing, and vendace larvae by beach seine . The research area was divided in a polluted (0.5-4.0% effluent), an intermediate (0.1-0.5%) and a 'clean' reference area . The fish community in sublittoral and profundal waters in the lake was dominated (> 60%) by perch and roach . Relative abundance of fish was highest in the polluted area, and lowest in the reference area . The number of species caught was similar among areas . The abundance of bleak and ruffe was highest in the polluted area, while the abundance of vendace and whitefish was highest in the intermediate and reference area . The fish fauna of stony shores in the lake was dominated by bullhead, stone loach and minnow, densities were lowest at polluted shores and highest in the intermediate area . Minnow, apparently a more sensitive species to pulp mill effluents, were not caught at the most polluted shores . The catch of vendace larvae was similar among areas, larvae were also caught in the vicinity of the mills . Compared with before the modernization at the mills, the relative abundance of perch in the polluted area was increased, ruffe decreased, while populations of whitefish and vendace showed signs of recovery . These changes may be explained by the reduced nutrient load and toxicicity of pulp mill effluents . At present, the fish community in the polluted area can be considered typical for a moderate eutrophication. Water Sci Technol, 2001, 44(11-12), 93 - 100 Environmental impacts to the Everglades ecosystem: a historical perspective and restoration strategies; Chimney MJ et al.; The Everglades is a vast subtropical wetland that dominates the landscape of south Florida and is widely recognized as an ecosystem of great ecological importance . As a result of anthropogenic disturbances over the past 100 years (i.e., agricultural and urban development, eutrophication resulting from stormwater runoff, changes in hydrology and invasion of exotic species), the biotic integrity of the entire Everglades is now threatened . To protect this valuable resource, the state of Florida and the Federal Government, in cooperation with other interested parties, have developed a comprehensive restoration strategy that addresses controlling excess nutrient loading and reestablishment of a more natural hydrology . These efforts include building approximately 17,000 ha of treatment wetlands, referred to as Stormwater Treatment Areas, to treat surface runoff before it is discharged into the Everglades . We briefly discuss the history of the Everglades in the context of environmental disturbance and outline the steps being taken to ensure its survival for future generations. Water Sci Technol, 2001, 44(11-12), 591 - 8 Buffer zones promoting oligotrophication in golf course runoffs: fiddler crabs as estuarine health indicators; George RY et al.; Nitrogen pollution above a threshold level induces a eutrophication process in coastal creek ecosystems and consequently impacts on the water quality . The remedy for this scenario is the introduction of methods to enhance oligotrophication by means of constructed wetlands and buffer zones . This paper discusses new data on nitrogen flux and population changes in the primary consumers in the Bradley Creek ecosystem, adjacent to the Duck Haven Golf Course in southeastern North Carolina . In 1998-99, over different seasons, density distribution of the field populations of the fiddler crab Uca minax, was monitored as an indicator of environmental health . A control site at Whiskey Creek, adjacent to the University Center for Marine Sciences, was monitored in the same period since this site is not influenced by any golf course nutrient flux . The results pointed out that threshold level for optimum population density in Spartina grandiflora salt marsh is 0.1 mg/L of nitrates . A dense crab population, adjacent to the golf course with a buffer zone, was indicative of restoration of the estuarine ecosystem . A model, involving the use of constructed wetlands for oligotrophication, is being prepared on the basis of studies conducted by the University of South Alabama for a stormwater wetland constructed adjacent to the university's golf course. Water Sci Technol, 2001, 44(11-12), 289 - 94 Determining ecologically acceptable nutrient loads to natural wetlands for water quality improvement; Keenan LW et al.; Natural wetlands often function as nutrient sinks, reducing nutrient inputs into lakes and streams . P loading from anthropogenic sources has significantly affected many natural wetlands . This paper describes a method to determine an acceptable P load to natural wetlands based on ecological principles . This approach can be used to determine how much P can be assimilated without diminishing species diversity and, thereby, sets a limit for cultural eutrophication of natural wetlands . The basis for determining an acceptable load is management of risk to species diversity by determination of the maximum area of a wetland that can be put at risk while preserving biodiversity of the overall wetland system . Two cases are distinguished: 1) simple-stress, where growth of the affected area immediately increases risks for species loss, and 2) subsidy-stress, where growth of the affected area first benefits then diminishes net species diversity. Water Sci Technol, 2001, 44(11-12), 171 - 6 Removal of nutrients from combined sewer overflows and lake water in a vertical-flow constructed wetland system; Gervin L et al.; Lake Utterslev is situated in a densely built-up area of Copenhagen, and is heavily eutrophicated from combined sewer overflows . At the same time the lake suffers from lack of water . Therefore, a 5,000 m2 vertical flow wetland system was constructed in 1998 to reduce the phosphorus discharge from combined sewer overflows without reducing the water supply to the lake . During dry periods the constructed wetland is used to remove phosphorus from the lake water . The system is designed as a 90 m diameter circular bed with a bed depth of c . 2 m . The system is isolated from the surroundings by a polyethylene membrane . The bed medium consists of a mixture of gravel and crushed marble, which has a high binding capacity for phosphorus . The bed is located within the natural littoral zone of the lake and is planted with common reed (Phragmites australis) . The constructed wetland is intermittently loaded with combined sewer overflow water or lake water and, after percolation through the bed medium, the water is collected in a network of drainage pipes at the bottom of the bed and pumped to the lake . The fully automated loading cycle results in alternating wet and dry periods . During the initial two years of operation, the phosphorus removal for combined sewer overflows has been consistently high (94-99% of inflow concentrations) . When loaded with lake water, the phosphorus removal has been high during summer (71-97%) and lower during winter (53-75%) partly because of lower inlet concentrations . Effluent phosphorus concentrations are consistently low (0.03-0.04 mg/L) . Ammonium nitrogen is nitrified in the constructed wetland, and total suspended solids and COD are generally reduced to concentrations below 5 mg/L and 25 mg/L, respectively . The study documents that a subsurface flow constructed wetland system can be designed and operated to effectively remove phosphorus and other pollutants from combined sewer overflows and eutrophicated lake water. J Environ Qual, 2001 Nov-Dec, 30(6), 2105 - 12 Rapid incidental phosphorus transfers from grassland; Preedy N et al.; In Britain, frequent rainfall means that there is a high potential for rapid, direct (incidental) losses of phosphorus (P) to occur after fertilizer or manure application . However, despite the known contribution of P to the eutrophication of water bodies in Britain, such incidental transfers have received little experimental attention . To rectify this, we used lysimeter plots (each 3 x 10 m) to investigate incidental transfers in a composite of overland and lateral subsurface flow (0-27 cm) following the application of different P sources . The treatments used were triple super phosphate (TSP), dairy slurry (Slurry), an equal mix of TSP plus slurry (TSP + Slurry), and no P (Zero P) . The treatments were applied to wet soil at a rate of 29 kg ha(-1) . In the following 169 h, 48.8 mm rainfall (intensity < or =3 mm h(-1)) resulted in total phosphorus (TP) exports between 1.8 and 2.3 kg ha(-1) . A single 4-h period (with overland flow) accounted for 33 to 46% of overall loads from the P-amended treatments . Concentrations in discharge from TSP + Slurry and TSP peaked at 11000 microg TP L(-1) (67-68% as reactive P < 0.45 microm (RP<0.45) . Slurry peaked at 7000 microg TP L(-1), 66% as particulate TP (>0.45 microm) and 20% as RP<0.45 . Even in subsurface flow, concentrations exceeded 3000 microg TP L(-1) for all P-amended treatments . Incidental TP concentrations in plot discharge were up to 110-fold higher than those considered eutrophic in inland waters . We suggest that targeting short-term management decisions for P applications is the most immediately viable method to mitigate P loss and benefit the environment. J Environ Qual, 2001 Nov-Dec, 30(6), 2018 - 25 Evaluation of the phosphorus index in watersheds at the regional scale; Birr AS et al.; Agricultural losses of phosphorus (P) in runoff are a primary cause of eutrophication in many freshwater systems . A modified version of the P Index originally developed jointly by the USDA (Agricultural Research Service {ARS}, Cooperative State Research, Education, and Extension Service {CSREES}, and Natural Resources Conservation Service {NRCS}) was used to prioritize P loss vulnerability at the regional scale from 60 watersheds located within Minnesota using readily available data related to the transport and sources of P . This modified version of the P Index was created for a regionally based analysis of the index . Validation of the P Index rating was conducted using long-term water quality monitoring data consisting of total P concentrations collected from watersheds and lakes . The modified version of the P Index produced a strong correlation between P Index rating and total P stream monitoring data in watersheds (r2 = 0.70) excluding the Red River Basin . An equally strong relationship was observed between P Index rating and lake water quality (r2 = 0.68) using the modified P Index . The P Index ratings for the Red River Basin showed good correlation with observed total P stream monitoring data (r2 = 0.51); however, the P Index ratings were smaller than in other basins . The results of this study suggest that, with certain limitations, the P Index can be used at the regional scale to prioritize P loss vulnerability using state and national databases . Regional P Index ratings represent the average risk for agricultural land within the entire watershed. Zhonghua Zhong Liu Za Zhi, 2001 Mar, 23(2), 96 - 9 {The relationship between cyanotoxin (microcystin, MC) in pond-ditch water and primary liver cancer in China}; Yu S et al.; OBJECTIVE: To explore the relationship between primary liver cancer (PLC) and MC in drinking pond-ditch water . METHODS: Epidemiological and ecological assays, Meta-analysis and risk assessment were used in this study . Cyanotoxin (Microcystin, MC) in the water of different sources was detected by ELISA . The F344 and HBVx transgenic mice were used to confirm the promotion effect on PLC and the synthetically carcinogenic effect of HBV, aflatoxin and MC . RESULTS: Using Meta-analysis the results of six case-control studies showed that the pooled odds ratio (OR) was 2.46 (95% CI 1.69-2.59), population attributable rick (PAR) was 30.39% (95% CI, 23.30%-37.47%), heterogeneity test P > 0.05 . Eutrophication led to cyanobacterial bloom in the pond-ditch water . Cyanotoxin released from dead cyanobacteria was hepatotactic tumor promoter . In HBVx transgenic rats, hepatocellular carcinoma was induced by the joint administration of aflatoxin B1 and cyanotoxin . Epidemiological study showed that the recombined index of HBsAg, aflatoxin-albumin adducts and drinking of pond-ditch water correlated with PLC mortalities in 13 townships . CONCLUSION: Microcystin in the pond-ditch water is a hepatotactic toxin which can induce hepatitis and promote development of hepatocellular carcinoma . The combined effect of microcystin, HBV and aflatoxin may be responsible for the endemicity of PLC. Water Res, 2002 Jan, 36(1), 49 - 58 Biochemical model of glucose induced enhanced biological phosphorus removal under anaerobic condition; Wang N et al.; Enhanced biological phosphorus removal (EBPR) is playing an increasingly important role in controlling the eutrophication phenomenon in natural waters . It is believed that substrates other than acetate exert significant effects on the EBPR process . In this research, it was found that glucose could be used as the dominant substrate to induce and maintain a successful EBPR process . However, compared to the conventional EBPR process using acetate as the dominant substrate, it was found that less PO4-P was released into the medium and 3-hydroxyvalerate (3-HV) enriched poly-beta-hydroxyalkanoate (PHA), rather than 3-hydroxybutyrate (3-HB) enriched PHA, was accumulated during the anaerobic condition . According to the experimental results, a new biochemical model is hypothesized for the anaerobic metabolism of glucose . It is reasoned that the predominance of 3-HV enriched PHA is employed to balance the internal redox during the anaerobic condition . The Entner-Doudoroff (ED) pathway is likely used for anaerobic glucose metabolism when the bacteria demonstrate good EBPR performance, because the ED pathway necessitates the use of polyphosphate for energy purposes. J Environ Health, 2001 Dec, 64(5), 25 - 32 Sources of the eutrophication problems associated with toxic algae: an overview; Pitois S et al.; Blooms of cyanobacteria (toxic blue-green algae) can produce health and environmental hazards in water, including water used for drinking or recreational purposes . How, why, and when these blooms are produced, as well as how to deal with them, are questions whose answers are vital to the safeguarding of public health in regions where the algae occur . The blooms are linked to eutrophication of water, and this paper discusses the eutrophication problems, their nature, and their relevance to the production of cyanobacteria . Nutrient limitations on algal productivity are considered, as is the involvement of the atmosphere, the storage of nutrients in soils, and the influence of anthropogenic activity. Int J Hyg Environ Health, 2001 Nov, 204(2-3), 143 - 55 Spatial impact of the Oder river plume on water quality along the south-western Baltic coast; Schernewski G et al.; The Oder (Odra) river is the most important nutrient source and pollutant for the south-western Baltic Sea . Adjacent German-Polish coastal waters, the Oder (Szczecin) Lagoon and the Oder (Pomeranian) Bight therefore suffer from severe eutrophication and water quality problems . At the same time, summer (bathing) tourism is the most important economical factor in this coastal zone, especially on the islands of Usedom and Wolin . On the basis of model simulations and remote sensing data we analysed the spatial extent and variability of the Oder river plume in the lagoon and the Balic Sea in common summer situations and during the extreme Oder flood in August 1997 . Water quality shows pronounced gradients between coastal waters and open Baltic Sea . In the lagoon, it usually takes more than 6 weeks until Oder water enters the large western bay, the Kleines Haff . During transport, degradation, transformation and sedimentation processes alter the water quality and prevent the inner coast of Usedom from direct impact of polluted Oder water . Ongoing nutrient supply promotes intensive algal proliferation in all parts of the lagoon and contributes to the low water transparency . Oder water passing the lagoon and entering the Baltic Sea is transported over long distances in narrow bands along the shore . Under easterly winds the water quality near well-known spas on Usedom is reduced due to Oder river plume impact . Upwelling effects can have negative impact on water quality, too . Intensive blooms of potentially toxic blue-green algae species, are the rule in the lagoon and frequent in the Oder Bight in summer . They are a hazard and limit the acceptance of swimming beaches at the inner coast of Usedom . Practical consequences of variable water quality gradients e.g . on hygienic water sampling are discussed. Ying Yong Sheng Tai Xue Bao, 2001 Aug, 12(4), 590 - 2 {Ecological engineering for eutrophication control in lake}; Sun G et al.; An ecological engineering was conducted for eutrophication control in the Nanhu Lake of Changchun . In 1996, the removal of phosphorus by harvesting aquatic macrophytes and fishes was 149.6 kg and 189.9 kg, respectively, and the phosphorus fixed in molluscs was 153.4 kg . The total output was 492.9 kg, which amounted approximately to the annual phosphorus input to the lake . After ecological engineering, the water quality turned better, the TP concentration in lake water decreased, the phytoplankton density reduced, and the number of phytoplankton species increased . The roles of molluscs and fish in controlling lake eutrophication should be further studied . Ecological engineering is an ideal method to control the eutrophication of urban lakes. Ambio, 2001 Sep, 30(6), 369 - 75 Multipond system: a sustainable way to control diffuse phosphorus pollution; Yin C et al.; Diffuse pollution from agricultural land is one of the main causes for lake eutrophication . Multipond systems, an ancient invention in China, are composed of many tiny ponds and ditches, scattered in agricultural fields . After a long period of research in an experimental watershed in Liuchahe, it was found that multipond systems constitute diffuse pollution control . They have a large capacity for water storage and serve to control the export of water, suspended matter, and phosphorus . Multipond systems significantly reduce runoff velocity . Sediments and phosphorus retained in the Liuchahe watershed were 14.38 x 10(6) and 7016 kg yr-1, respectively (area 691.6 ha) . Irrigation provides an effective way to recycle and remove phosphorus . The use of multipond systems is a sustainable way to recycle valuable nutrients and reduce their discharge and thus pollution of downstream lakes. Water Sci Technol, 2001, 44(7), 63 - 8 Analysis of the hydrology and flow of nitrogen in 17 Danish catchments; Andersen HE et al.; In the search for tools for evaluating the effects of national action plans combating diffuse nutrient pollution causing eutrophication of surface waters, a study of the nitrogen (N) flow in 17 Danish agricultural catchments was carried out . Data on N input and N harvest for the agricultural year of 1993/1994 was obtained from questionnaire surveys facilitating the set up of N balances . Net export of N from the catchments measured at the outlet was obtained from time-series of stream water chemistry and discharge from 1993-1997 . N leaching from the root zone of each field was calculated using an empirical model . A physically based lumped rainfall-runoff model was used for separating the hydrograph time-series into three runoff components: baseflow, interflow and overland flow . Large regional variations in net N input were found ranging from 62 kg N ha(-1) yr(-1) in the loamy eastern part of the country dominated by cereal production to 137 kg N ha(-1) yr(-1) in the western part characterised by less fertile sandy soils and dominated by animal husbandry . N leaching from the root zone showed a corresponding variation with regional averages ranging from 34.5 kg N ha(-1) yr(-1) to 90.9 kg N ha(-1) yr(-1) . No similar regional pattern could however be found regarding net N export, and no relationship could be established between net N export and root zone N leaching . This finding was ascribed to a varying and in some catchments very high (>80%) N retention during subsurface transport to the stream . The hydrological modelling revealed that loamy catchments had a high proportion of quick flow (overland flow + interflow), whereas baseflow dominated the sandy catchments . Further, a highly significant relationship between N retention and proportion of quick flow was found emphasising the importance of understanding the hydrological pathways . This should be taken into consideration when evaluating the N loading of surface waters resulting from a given agricultural practice and the effects of possible changes in this practice. Water Sci Technol, 2001, 44(7), 35 - 40 Study of the distribution of non-point source pollution in the watershed of the Miyun Reservoir, Beijing, China; Wang X et al.; Nitrogen and phosphorus are major nutrients to cause eutrophication to degrade the water quality of the Miyun Reservoir, a very important drinking water source of Beijing in China . These are mainly from non-point sources . The watershed in Miyun County is selected as the study region with a total area of 1400 km2 . Four typical monitoring catchments and two experimental units were used to monitor the precipitation, runoff, sediment yield and pollutant loading related to various land uses in the meantime . The results show that the total nutrient loss amount of TN and TP is 898.07 t/a, and 40.70 t/a, respectively, in which nutrient N and P carried by runoff is 91.3% and 77.3%, respectively . There is relatively heavier soil erosion at the northern mountain area whereas the main nutrient loss occurs near the northeast rim of the reservoir . Different land uses influence the loss of non-point source pollutants . The amount of nutrient loss from agricultural land per unit is the highest, nutrient loss from forestry is the second highest and that from grassland is the lowest . However, due to the variability of land use areas, agricultural land contributes the greatest amount of TP and forestry lands the greatest amount of TN. Water Sci Technol, 2001, 44(6), 35 - 46 Multipurpose use and water quality challenges in Lac de Guiers (Senegal); Cogels FX et al.; Lac de Guiers (Guiers Lake) is a shallow lake in West Africa . Its waters are used mainly for irrigation and drinking water . Recent engineering in the Senegal River Valley has changed the lake's functioning and led to new water quality conditions . This article describes the water quality effects of the management of the lake and use of its waters, with special emphasis on salinity and eutrophication. Water Sci Technol, 2001, 44(6), 19 - 26 Eutrophication study of twenty reservoirs in Taiwan; Chang SP et al.; Taiwan is an island off the southeastern coast of China with total area of roughly 36,000 km2 . The geographic position of Taiwan is between 21degrees 45' 25" to 25 degrees 56' 31" north latitude and 119 degrees 18' 3"to 124 degrees 34' 30" east longitude and includes both tropical and subtropical areas . The study was carried out at twenty main reservoirs in Taiwan area from 1994 to 1998 . The study revealed that the water quality of most reservoirs gradually deteriorated during the study period . Total phosphorus concentrations over 60 microg/L were observed in 12.5% of these reservoirs in 1994, but in 22.2% of these reservoirs in 1998 . Total nitrogen concentrations over 1.0 mg/L were observed in 37.5% of these reservoirs in 1994, but in 94.4% of these reservoirs in 1998 . Secchi disc transparency below 2 m was observed in 75% of these reservoirs in 1994, but in 83.3% of these reservoirs in 1998 . Chlorophyll a concentrations over 15 mg/m3 were observed in 12.5% of these reservoirs in 1994, but in 27.8% of these reservoirs in 1998 . The TN:TP mass ratios (wt/wt) of all the studied reservoirs except Akungting Reservoir, Fongshan Reservoir, and Chengching Reservoir are higher than 16 . The study results on nutrient limitation indicated that phosphorus is the primary limiting nutrient in Taiwan reservoirs except Akungting Reservoir, Fongshan Reservoir, and Chengching Reservoir. Nature, 2001 Nov 8, 414(6860), 166 - 7 Nitrate flux in the Mississippi River; McIsaac GF et al.; Increased delivery of biologically available nitrogen to estuaries and coastal oceans in recent decades has been linked to eutrophication and seasonal hypoxia in the northern Gulf of Mexico and elsewhere . We have developed a model that accounts for 95% of annual variation in delivery of nitrate to the Gulf of Mexico by the Mississippi River in 1960-98 . Retrospective analysis indicates that this nitrate flux could have been reduced by 33% if the use of nitrogen-containing fertilizer in the Mississippi River basin had been cut by 12%. Ambio, 2001 Aug, 30(4-5), 217 - 21 Fish stocks in the Baltic Sea: finite or infinite resource? Ojaveer E, Lehtonen H. Human-induced environmental changes, especially eutrophication, and fluctuations of natural environmental conditions under the changes in climate and solar activity affect the reproduction and growth of various fish species and communities in the Baltic Sea . The importance of human impacts has increased considerably during the last decades, overshadowing in many cases natural factors . High exploitation rates have depressed some valuable fish species and affected the species dominance hierarchy . Oxygen depletion in deeper layers progressively deteriorates the living conditions of certain marine species . Mass immigration of nonindigenous species with ballast waters can seriously affect ecosystems and fish stocks . The summary effect of these variables upon marine, relict and freshwater species can yield unexpected results . Fish resources should be properly assessed and managed by their natural units (populations) . Based on cyclic fluctuations of global climatic processes, composition of long-term forecasts on changes in the structure and abundance of fish fauna should be started. Ambio, 2001 Aug, 30(4-5), 202 - 9 The meltdown of biogeographical peculiarities of the Baltic Sea: the interaction of natural and man-made processes; Leppakoski E et al.; The biogeographical peculiarities of the Baltic Sea have developed since the last glacial period . The characteristic mixture of marine, brackish water, and freshwater species, and relicts from previous periods in the Baltic, is threatened by ongoing environmental changes . This review focuses on the recent impacts of nonindigenous species, eutrophication, and a temporary oxygen deficit in the deep basins, on the biogeographical integrity of the Baltic on different spatial and time scales . Today the biota of brackish waterbodies are exposed to each other because of the breakdown in geographical barriers due to shipping traffic, leading to an exchange of species and further homogenization of aquatic animal and plant life worldwide. Ambio, 2001 Aug, 30(4-5), 184 - 9 Eutrophication, harmful algal blooms and species diversity in phytoplankton communities: examples from the Baltic Sea; Kononen K; Understanding the mechanisms that govern biological diversity in various environments is one of the greatest challenges for the scientific community of today . Compared to terrestrial and benthic habitats, mechanisms regulating species diversity in planktonic ecosystems have been dealt with relatively little . This is mainly due to the scarcity of the experimental evidence from field studies where the multitude of spatiotemporal scales have been covered with sufficient resolution . This paper discusses the peculiarities of the aquatic system as a growth environment for phytoplankton in comparison to terrestrial/connected systems . Examples of the regulation of species diversity in the Baltic Sea are presented. Ambio, 2001 Aug, 30(4-5), 172 - 8 The history of cyanobacterial blooms in the Baltic Sea; Finni T et al.; Long-term information on possible changes in cyanobacterial blooms in the Baltic Sea, formed mainly by Nodularia spumigena and Aphanizomenon sp., was sought in published records in historical (years 1887-1938) and modern (years 1974-1998) phytoplankton data sets . Old and new sampling methods and fixatives were tested to improve the comparison of data that had been collected and analyzed in different ways . A hundred years ago, plankton was mainly of interest as a source of fish food; eutrophication problems were only locally reported from the coast, mainly in southern haffs and the receiving waters of larger cities . There were few recordings of open-sea blooms before World War II . Abundances of Nodularia spumigena and Aphanizomenon sp . were low in the old material, and 137 summer samples from 1887-1938 showed no peak abundance . High abundances are common in the new material, and the range of the numbers of both taxa has increased markedly relative to the old material . Since the 1960s, cyanobacterial blooms have been common in the open sea in both the Baltic proper and the Gulf of Finland, indicating high availability of nutrients. Mar Environ Res, 2001 Oct, 52(4), 323 - 49 Benthic macrofauna changes in areas of Venice lagoon populated by seagrasses or seaweeds; Sfriso A et al.; Two areas of the Venice lagoon populated by seagrasses (three stations covered by Cymodocea nodosa (Ucria) Asherson, Zostera marina Linnaeus, Zostera noltii Hornemann) or seaweeds (two stations: one covered by Ulva rigida C . Agardh and another at present without seaweed biomass) were monitored by means of six surveys over a year in order to study macrofaunal composition and seasonal changes . The seagrass stations showed a mean species richness (28-30 S m(-2)), individual abundance (1854-4018 N m(-2)) and biomass (22.3-37.7 g m(-2) ash-free-dry-weight, AFDW) ca . 3-8 times higher than those populated by seaweeds (10-15 S m(-2), 494-1395 N m(-2) and 5.6-13.7 g m(-2) AFDW) . Differences among seagrass or seaweed stations were much lower . The Ulva-dominated station showed a macrofauna completely different both from the other stations and the communities recorded ca . 30 years ago, before the prolific growth of Ulva . In this station, frequent biomass decompositions and anoxic crises created critical conditions for life favouring organisms with reduced life cycles, younger individuals and the epifaunal species instead of the infaunal ones . In particular, Ulva grazers and scrapers such as Gammarus aequicauda Stock and Gibbula adriatica Philippi were found to be by far the most abundant species, whereas the taxa characteristic of the associations found in the past, in the presence of seagrasses or seaweeds and typical of low eutrophicated environments, appear strongly reduced . Marked differences in the macrophyte dominance and in the bio-physico-chemical variables which characterise the main environmental conditions of the Venice lagoon support the different distribution and composition of macrofaunal communities . Seaweed stations appear mainly governed by the seasonal cycles of these un-rooted macrophytes which, by alternating periods of production and decomposition, are responsible for the drastic reduction of macrofauna biodiversity and biomass . Conversely, seagrass stations exhibit a better oxidisation of the environment and show conditions more favourable for macrofauna colonisation, especially in the presence of macrophytes which are characterised by very well developed below-ground systems such as Cymodocea nodosa. Chemosphere, 2001 Nov, 45(6-7), 827 - 34 Seasonal variations in phosphorus species in the surface sediments of the Gulf of Riga, Baltic Sea; Aigars J; The redox-dependent variations in concentrations of phosphorus at two different accumulation bottom areas were investigated in the Gulf of Riga (Baltic Sea) between December 1993 and January 1995 . The sediment samples from nine sampling occasions were analyzed for phosphorus forms and redox potential . The average concentrations of total phosphorus measured in 0-1 cm (65 and 89 micromol P g(-1) for sites G5 and T3, respectively) were among the highest reported from the entire Baltic Sea . Redox-dependent "mobile" phosphorus (MP) contributed more than 50% of total in the uppermost-oxidized centimeter, whereas in reduced layers it was 16-18% throughout the year . The significant differences (ANOVA, P<0.01) among months of inorganic phosphorus (IP) concentration at 0-1 cm were observed at site G5 due to temporary accumulation of mobile phosphorus mediated by redox-dependent bacteria activity during summer . On the contrary no accumulation was observed at T3 probably as a result of low redox potential caused by high accumulation rates and low bioturbation . Although the water column above sediments remained oxic throughout the investigation period, the redox potential at site T3 was close to the redoxcline (i.e., +230 mV) during summer . Further increase of eutrophication might lead to development of anoxic conditions at sediment-water interface and that in turn will result in rapid release of redox-dependent phosphorus stored in surface sediments . The availability of excess phosphorus will further enhance eutrophication in partly phosphorus-limited Gulf of Riga. Ecotoxicol Environ Saf, 2001 Oct, 50(2), 143 - 52 Do food processing industries contribute to the eutrophication of aquatic systems? Tusseau-Vuillemin MH. Eutrophication is the enrichment of water bodies with plant nutrients and precursors, typically nitrogen, phosphorus, and organic matter . There exists a "natural" and slow eutrophication, which, over geological times, turns a lake into a marsh and then dries it entirely . Today, however, eutrophication is mostly referred to the human process that "results in the stimulation of an array of symptomatic changes, among which increased production of algae and macrophytes, deterioration of water quality and other symptomatic changes are found to be undesirable and interfere with water uses" as defined by the OECD in 1982 . This undesirable process is observed mostly in enclosed water bodies, such as lakes, but also in some rivers, some estuaries, and some coastal zones . In most freshwater systems, phosphorus has been identified as the "limiting nutrient" to phytoplankton development . This nutrient is brought to aquatic environments from rock weathering, soil leaching, and rain (natural sources), but also and mostly from agricultural runoff and domestic sewage . Some food processing industries (meat, vegetables, cheese processing) also contribute significantly to the phosphorus budget, even though the pollution may be due to floor and utensil cleaning rather than to direct food wastes . Environ Sci Technol, 2001 Oct 15, 35(20), 4126 - 31 Stability of phosphorus within a wetland soil following ferric chloride treatment to control eutrophication; Sherwood LJ et al.; Addition of iron and aluminum compounds has become an increasingly popular method to regulate phosphorus eutrophication in lakes and reservoirs . It has been proposed that ferric chloride addition to agricultural runoff entering the northern Everglades could provide a means for enhancing natural mechanisms of phosphorus removal from the wetland . In this study we added ferric chloride to Everglades water spiked with 32PO4, incubating the resulting precipitates in microcosms simulating the Everglades ecosystem . 32P activity and reduction-oxidation (redox) potentials were monitored to determine if the 32P was released into the overlying water column due to iron reduction . Results of redox potential measurements and 32P activity indicate that although reducing conditions exist in the soil, on average less than 1% of the added 32P was measured in the water column during the 139-day incubation . Ferric chloride addition thus might prove an effective means of long-term phosphorus retention in the Florida Everglades and perhaps other wetland systems. Sci Total Environ, 2001 Oct 20, 278(1-3), 113 - 25 Phosphorus losses in subsurface flow before and after manure application to intensively farmed land; McDowell RW et al.; A study was conducted to examine the loss of P in subsurface flow from three cultivated soils of varying soil P concentrations . Measurements were made in flow waters from the soils before applying manure and then 3 weeks after sowing the soils to grass . An additional measurement of P in flow waters was made 1 year later . Dissolved reactive P (DRP) concentrations measured in flow water before (0.15-0.20 mg l(-1)) and after (0.39-0.51 mg l(-1)) manure application exceed current estimates of those required to promote surface water eutrophication (0.05 mg l(-1)) . Concentrations of DRP1 year after manurial application increased compared to 3 weeks after application and was attributed to the slow movement of P down the cultivated soil . Concentrations of soil P were significantly increased down the soil profile and attributed to the P saturation of soils before manurial application . The results suggest that despite the establishment of fast growing grass, P concentrations would not be mitigated in the short-term (= 1 year), due to the large contribution of P in subsurface pathways. Parasitology, 2001 Sep, 123(Pt 3), 257 - 69 Long-term dynamics of Ligula intestinalis and roach Rutilus rutilus: a study of three epizootic cycles over thirty-one years; Kennedy CR et al.; Data are presented on 2 full epizootic cycles and the start of a third of Ligula intestinalis in roach Rutilus rutilus in a small lake, and the relationships of these cycles to the densities of rudd, Scardinius erythrophthalmus, and Great Crested Grebes, Podiceps cristatus, over 31 years . The parasite was introduced to the lake by P . cristatus in 1973 at a time when the roach population had increased in response to eutrophication to a level at which individual fish growth was stunted and the hithero dominant rudd population had declined in numbers as a consequence of inter-specific competition with roach . Ligula prevalence peaked at 28% in only 2 years: thereafter parasite-induced host mortality caused a decline in the roach population, releasing fish from stunting and allowing the rudd population to recover . The consequent improved growth of roach individuals and their short life-span reduced Ligula transmission rates and prevalence levels declined to approximately 1% although Ligula nevertheless persisted for a further 10 years . Following a massive winter-kill of the fish populations in 1984-1985, fish and Ligula numbers declined to barely detectable levels and the parasite disappeared from samples . Rudd recovered first, then roach and interspecific competition again led to a decline in rudd numbers . This increase in roach numbers led to a decrease in roach growth rates, which coincided with the re-colonization of the lake by Ligula . This second epizootic of Ligula peaked within 2 years in 1991-1992, when up to 78% of roach were infected with a maximum abundance of 2.2 parasites and intensity of 21 parasites . Heavy parasite-induced mortality of roach led to a decline in numbers, an improvement in individual growth rate and a reduction of Ligula transmission rates such that the epizootic died out in 1996 . Similar conditions of roach numbers and growth prevailed at the start of a third cycle in 1998 . The course of events over the second cycle was so similar to that of the first that it confirms the interpretations of that cycle . Comparison with other localities shows that epizootics of Ligula always coincide with rapid increases in roach numbers, for whatever cause, and stunted growth, which together attract piscivorous birds . At the start of a cycle Ligula is a major determinant of the population dynamics of the roach, but at the end of the cycle the fish population dynamics determine those of the parasite . The cycles are not regulated and the roach-Ligula system is inherently unstable. Vet Hum Toxicol, 2001 Oct, 43(5), 294 - 7 The toxicology of microcystin-LR: occurrence, toxicokinetics, toxicodynamics, diagnosis and treatment; Bischoff K; Cyanobacterial blooms occur worldwide and present an increasing problem due to eutrophication of lakes . Microcystins, especially microcystin-LR, are microcyclic heptapeptide hepatotoxins and are the most common and potent toxins associated with cyanobacteria . Microcystin is rapidly taken up by hepatocytes through carrier-mediated transport . Once in the hepatocyte, microcystin causes structural damage to the cell indirectly by inhibiting protein phosphorylases 1 and 2A, which are needed for regulation of structural proteins of the cell . Acute liver hemorrhage and death occur with high doses of microcystin-LR, which is also a potent tumor promoter in laboratory rats . The significance of microcystin to human health has been debated; however, poisoning in humans has occurred due to contaminated dialysis water . Microcystin in contaminated drinking water may be the cause of elevated rates of primary liver cancer in some areas of China . Problems with hepatotoxic cyanobacteria have been most seen in livestock . Treatment of confirmed microcystin toxicosis in livestock is likely to be unrewarding, so prevention is important . Wild mammals, birds, fish, insects, and microinvertebrates may also be affected by microcystin. J Environ Qual, 2001 Sep-Oct, 30(5), 1829 - 35 Using phosphorus concentration in the soil solution to predict phosphorus desorption to water; Torrent J et al.; The growing concerns about water eutrophication have made it urgent to restrict losses of phosphorus (P) from agricultural soils and to develop methods for predicting such losses . In this work, we used the paradigm of P sorption-desorption curves to confirm the hypothesis that the amount of dissolved reactive phosphorus (DRP) released to a dilute electrolyte tends to be proportional to the concentration of DRP in the soil solution raised to a power that decreases with increasing solution to soil ratio (W) . The hypothesis was tested for a group of 12 widely ranging European agricultural soils fertilized with P in excess of crop needs . Phosphorus desorption was studied under near-static and turbulent conditions in laboratory experiments . The concentration of DRP in the 1:1 soil to water extract (P1:1) was used as a proxy for the DRP concentration in the soil solution . The amount of desorbed P was found to be correlated with P1:1 raised to a power that decreased from 0.7 to 0.9 at W=100 to 0.2 to 0.4 at W=10 000 . Correlation was not improved by introducing additional variables related to P sorption-desorption properties . Olsen P was found to be of lower predictive value than P1:1 . Also, the index of degree of soil saturation with phosphorus (DSSP) based on oxalate extraction failed to predict P desorption . The fact that P1:1 seemingly predicts P desorption accurately for a wide range of soils makes it potentially useful in areas of high soil diversity. Huan Jing Ke Xue, 2001 Jul, 22(4), 104 - 7 {Relationship between eutrophication control and reservoir operation}; Jia H et al.; Choosing Miyun Reservoir as a research background, the spatial distribution characteristics of water quality in the reservoir were analyzed, and the relationship between reservoir operation and-eutrophication control was discussed . With the assistance of water quality model and the monitored data, measures that wiping off the nutrients combined with the flood prevention operation was proposed . At last, the feasibility of the measure was also discussed. Water Res, 2001 Oct, 35(15), 3517 - 36 Integrated modelling of eutrophication and organic contaminant fate & effects in aquatic ecosystems . A review; Koelmans AA et al.; Eutrophication and contamination with micropollutants have been major problems in water quality management . Both problems have been subjected to extensive research and modelling but traditionally are treated separately . Traditional simulation models for aquatic systems can be categorised as eutrophication models, contaminant fate models, food web models and food chain bioaccumulation models . Because they are single issue models, many interactions and feedbacks between the food web, nutrient and toxicant cycles are missed . Linking these models is essential to evaluate the fate and risks of contaminants in systems with changing nutrient loading, to assess the natural attenuation of contaminants or to understand the selfpurifying capacity of ecosystems . Combination of the single issue models requires inclusion of 'interaction processes' to account for the coupling between the (sub-) model types, such as organic carbon cycling . toxicity, transport and accumulation of organic contaminants in the food chain, and bottom up versus top down control of primary production and nutrient cycling . This review first provides a brief overview of traditional approaches in modelling eutrophication, contaminant fate, food web dynamics and food chain bioaccumulation . Second, five existing integrated eutrophication, fate and/or effects models are reviewed . Third, the gaps and limitations in modelling the four types of interaction processes are discussed . It is concluded that these models are invaluable tools to focus attention to feedback mechanisms that are often overlooked, to identify dominating processes in ecosystems, to formulate counterintuitive hypotheses on ecosystem functioning, or to assess short term risks of acutely toxic stressors . However, the potential of integrated models for long term simulations of contaminant exposure . food chain bioaccumulation and effects to higher trophic levels remains limited, mainly because of principal limitations in food web modelling . In contrast, the potential of integrated models for long term simulations of contaminant fate is better because the environmental distribution of contaminants is mainly determined by the major abiotic compartments and by biotic compartments at the base of the food chain. Water Sci Technol, 2001, 44(2-3), 329 - 36 Effect of residence times on River Mondego estuary eutrophication vulnerability; Duarte AS et al.; The south arm of the Mondego estuary, located in the central western Atlantic coast of Portugal, is almost silted up in the upstream area . So, the water circulation is mostly driven by tides and the tributary river Pranto discharges . Eutrophication has been taking place in this ecosystem during last twelve years, where macroalgae reach a luxuriant development covering a significant area of the intertidal muddy flat . A sampling program was carried out from June 1993 to June 1994 . Available data on salinity profiles and on nutrients loading into the south arm were used in order to get a better understanding of the ongoing changes . River Pranto flow discharges, controlled by a sluice, were also monitored . Integral formulations are typically based on assumptions of steady state and well-mixed systems and thus cannot take into account the space and time variability of estuarine residence times, due to river discharge flow, tidal coefficients, discharge(s) location and time of release during the tidal cycle . This work presents the hydrodynamics modelling (2D-H) of this system in order to estimate the residence times variability and to assess their effect on the estuarine eutrophication vulnerability, contributing to better environmental management strategies selection. J Environ Monit, 1999 Aug, 1(4), 403 - 7 An investigation of the origin and mobility of phosphorus in freshwater sediments from Bort-Les-Orgues Reservoir, France; Ruban V et al.; In order to assess the origin and the potential mobility of phosphorus (P) in the sediment of the Bort-Les-Orgues Reservoir, France, two sequential extraction schemes, i.e., the SMT (modified Williams method) and the Golterman schemes, were compared . Finally, the potential mobility of P in this sediment was estimated from results of sequential extraction . The SMT method appeared to be more satisfactory than the Golterman method, which is in accordance with results from a study currently carried out in the framework of the European programme Standards, Measurements and Testing . Iron-bound P and organic P were the dominant forms of P in the sediment; these forms are likely to be released at the sediment/water interface in case of anoxia and could diffuse into the water column, thus increasing the risk of eutrophication in this sensitive reservoir . The P stock (330 +/- 66 t) is not negligible and should be taken into account in any restoration project of the reservoir . The SMT procedure seems promising and will provide, in the near future, a valuable tool for water managers in the field of lake restoration. J Environ Monit, 1999 Feb, 1(1), 51 - 6 Selection and evaluation of sequential extraction procedures for the determination of phosphorus forms in lake sediment; Ruban V et al.; In order to achieve comparable measurements in the determination of phosphate forms in freshwater sediments, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission has launched a project the first step of which was to select and evaluate collaboratively existing extraction procedures . This was carried out through expert consultations and a literature survey, and was followed by the organisation of a first interlaboratory study for the evaluation of four sequential extraction schemes, one of which was selected as the most promising method for achieving comparability . This scheme, a modified version of the Williams protocol, was further tested in a second interlaboratory study . The so-called SMT extraction scheme seems promising and will provide, in the near future, a valuable tool for water managers in the field of lake restoration . It will be particularly helpful in estimating the stock of P potentially available, hence the risk of eutrophication due to internal P release. Water Res, 2001 Sep, 35(13), 3157 - 67 Lake ecosystem health assessment: indicators and methods; Xu FL et al.; A set of ecological indicators including structural, functional, and system-level aspects were proposed for a lake ecosystem health assessment, according to the structural, functional, and system-level responses of lake ecosystems to chemical stresses including acidification, eutrophication and copper, oil and pesticide contamination . The structural indicators included phytoplankton cell size and biomass, zooplankton body size and biomass, species diversity, macro- and micro-zooplankton biomass, the zooplankton phytoplankton ratio, and the macrozooplankton microzooplankton ratio . The functional indicators encompassed the algal C assimilation ratio, resource use efficiency, community production, gross production/respiration (i.e . P/R) ratio, gross production standing crop biomass (i.e . P/B) ratio, and standing crop biomass unit energy flow (i.e . B/E) ratio . The ecosystem-level indicators conisisted of ecological buffer capacities, energy, and structural energy . Based on these indicators, a direct measurement method (DMM) and an ecological modeling method (EMM) for lake ecosystem health assessment were developed . The DMM procedures were designed to: (1) identify key indicators; (2) measure directly or calculate indirectly the selected indicators; and, (3) assess ecosystem health on the basis of the indicator values . The EMM procedures were designed to: (1) determine the structure and complexity of the ecological model according to the lake's ecosystem structure; (2) establish an ecological model by designing a conceptual diagram, establishing model equations, and estimating model pararmeters; (3) compare the simulated values of important state variables and process rates with actual observations; (4) calculate ecosystem health indicators using the ecological model; and, (5) assess lake ecosystem health according to the values of the ecological indicators . The results of a case study demonstrated that both methods provided similar results which corresponded with the lake's actual trophic state. J Environ Qual, 2001 Jul-Aug, 30(4), 1474 - 80 Phosphorus sorption characteristics of estuarine sediments under different redox conditions; Pant HK et al.; Phosphorus (P) plays a major role in eutrophication of aquatic systems . Estuarine sediments could function as sources or sinks for P to the overlying water column depending upon their physico-chemical characteristics . Understanding of P sorption phenomena in estuarine sediments is important in regulating the P availability in estuaries . Phosphorus sorption characteristics of sediments from the Indian River Lagoon, Florida, USA, were determined to examine the role of selected physico-chemical properties of the sediments on soluble reactive P status in estuary water . Mean equilibrium P concentrations (EPCo) of 0.75 mg L(-1) and mean P sorption maxima (Smax) of 32.2 mg kg(-1) were obtained under anaerobic conditions, compared with EPCo of 0.05 mg L(-1) and Smax of 132.7 mg kg(-1) under aerobic conditions . The higher EPCo values under anaerobic conditions and the greater Smax values under aerobic conditions were associated with amorphous and poorly crystalline iron . These results suggest that sediments enriched with amorphous and poorly crystalline forms of iron act as an excellent reservoir for P by adsorbing excessive P in aerobic sediment zones and releasing it upon burial under anaerobic conditions . This study also indicates that P compounds in sediments independently maintain equilibrium with P in solutions . Thus, heterogeneous systems like soil and sediment simply behave as a mixture of homogeneous surfaces as far as their P sorption characteristics are concerned, and hence can be successfully described by the Langmuir and Freundlich models. J Environ Qual, 2001 Jul-Aug, 30(4), 1324 - 30 Effects of tillage and phosphorus placement on phosphorus runoff losses in a grain sorghum-soybean rotation; Kimmell RJ et al.; Phosphorus enhances eutrophication of fresh water bodies . This study was conducted to determine the influence of tillage and P placement on P losses in runoff water from a somewhat poorly drained soil (Woodson silt loam {fine, smectitic, thermic Abruptic Argiaquoll}, 1.0-1.5% slope) in a grain sorghum {Sorghum bicolor (L.) Moenchl-soybean {Glycine mar (L.) Merr} rotation . Chisel-disk-field cultivate (ChT), ridge-till (RT), and no-till (NT) in combination with 0 kg P ha(-1) or 24 kg P ha(-1) broadcast or knifed (applied prior to planting grain sorghum) were studied . Runoff volume and losses of sediment and P were summed over the growing season . Significant interactions between tillage and P placement for soluble P losses were found . For example, soluble P loss in 1999 for NT-broadcast in grain sorghum was 358 g ha(-1); significantly greater than 31 g ha(-1) for NT-knife or 23 g ha(-1) for NT-check . Similar results were found for RT but no such differences were found for ChT . Bioavailable P losses were generally highest with broadcast P placement and for NT and RT . Total P losses were significantly higher at 959 g ha(-1) with broadcast P on grain sorghum in 1998, compared with 521 g ha(-1) for the check and 659 g ha(-1) for the knifed P applications . Total P losses in 1999 for soybeans were only 18 g ha(-1) for NT, which was significantly lower than 75 g ha(-1) for ChT and 66 g ha(-1) for RT . The results indicate that broadcast P applications on RT and NT will increase P losses, but the influence of tillage was not consistent. Ambio, 2001 May, 30(3), 127 - 34 Quantification of anthropogenic threats to lakes in a lowland county of central Sweden; Brunberg AK et al.; An evaluation of the negative effects caused by anthropogenic influence on lake ecosystems was performed, using data from 143 catchments in Uppsala County, Sweden . The study included i) technical encroachments; i.e . construction of dams, dikes, etc . as well as effects of drainage of land; ii) pollution, i.e . eutrophication, acidification, and contamination by toxic substances; iii) introduction of nonnative species; and iv) exploitation of species populations . Severe damage was caused mostly by drainage of land followed by pollution by toxic substances and, to a smaller extent, introduction of nonnative species and eutrophication . Most lakes were subject to several types of disturbances, interacting in a complex pattern, which made it difficult to link the visible effects to the true causes of the disturbance . Future lake management should include analyses of all disturbances to the lake catchments, taking into account the historical perspective, in order to balance the threats/damages, in an analysis of the possibilities for maintaining biodiversity and sustainability in the ecosystems. Environ Toxicol Chem, 2001 Jul, 20(7), 1511 - 6 Acute sensitivity of nematode taxa to CuSO4 and relationships with feeding-type and life-history classification; Bongers T et al.; The acute sensitivity to CuSO4 of a broad range of nematode taxa was analyzed in order to assess the potential of changes to nematode community structure to serve as a practical tool for the bioindication of heavy-metal pollution . An easy-to-use experimental set-up was developed along with an appropriate mathematical response model in order to quantify the response characteristics of nematodes to CuSO4 pressure . Three similar experiments were conducted using water, dune sand, and sandy soil as media, each of which was subjected to 12 increasing concentrations of CuSO4 . In total, 130 response curves representing 70 nematode taxa were produced and analyzed . CuSO4 concentrations were normalized for differences in efficiency among media due to different adsorption . At low CuSO4 concentrations, many taxa exhibited stimulation rather than inhibition regarding recovery efficiency . At higher concentrations, the concentration level at which 50% of the nematode population was recovered after a 24-h incubation (recovery concentration 50% {RC50}) varied widely among taxa and ranged from 0.01 to 4 mM/L CuSO4 (normalized to water) . Stimulation of recovery efficiency and RC50 were negatively correlated with the colonizer-persister (C-P) classification of taxa, which discriminates nematodes according to their reproductive potential . The maturity index, which relates to a nematode community's state of disturbance and eutrophication, was negatively correlated with CuSO4 concentration . The properties of the applied test method are discussed as are the relationships between the investigated short-term toxicity effects and long-term toxicity processes in the field . From the large range of observed RC50 values, it is concluded that a meaningful sensitivity classification of nematodes should be possible and thus would allow for a sensitive bioindication of heavy-metal pollution . From the correlation between RC50 and C-P classification, the authors further conclude that the maturity index will, in addition to enrichment and disturbance, respond to heavy-metal pollution and thus may serve as a general indicator of soil health. Environ Toxicol, 2001 Jun, 16(3), 225 - 33 Apoptotic effect of cyanobacterial extract on rat hepatocytes and human lymphocytes; Mankiewicz J et al.; Toxic cyanobacterial blooms are an increasing problem in Poland . The production of cyanobacterial toxins and their presence in drinking and recreational waters represent a growing danger to human and animal health . This is connected with the increase of cyanobacterial biomass caused by excessive eutrophication of the water ecosystem . There is evidence that cyanobacterial hepatotoxins can act as a potent promoter of primary liver cancer . The apoptotic effect of microcystins in Polish cyanobacterial bloom samples on rat hepatocytes and human lymphocytes was observed using light and fluorescence microscopy, flow cytometry, and electrophoretic analysis . The incubation time needed to observe the first morphological apoptotic changes in hepatocytes was approximately 30 min; however, the characteristic biochemical changes in DNA were not observed even after 120 min . In lymphocyte cultures the morphological changes characteristic for apoptosis were observed after 24 h of incubation and a 48-h incubation was found to be optimal for analysis of internucleosomal DNA fragmentation, which is one of the main biochemical hallmarks of programmed cell death . These cells are an easily isolated and inexpensive material for medical diagnostics . Therefore the apoptotic changes, together with the clastogenic effect seen in lymphocyte cultures, are proposed as a future analytical method for these toxins. J Environ Qual, 2001 May-Jun, 30(3), 992 - 8 Effects of alum and aluminum chloride on phosphorus runoff from swine manure; Smith DR et al.; Phosphorus (P) runoff from fields fertilized with swine (Sus scrofa domesticus) manure may contribute to eutrophication . The objective of this study was to evaluate the effect of aluminum sulfate (alum) and aluminum chloride applications to swine manure on P runoff from small plots cropped to tall fescue (Festuca arundinacea Shreb.) . There were six treatments in this study: (i) unfertilized control plots, (ii) untreated manure, (iii) manure with alum at 215 mg Al L(-1), (iv) manure with aluminum chloride at 215 mg Al L(-1), (v) manure with alum at 430 mg Al L(-1), and (vi) manure with aluminum chloride at 430 mg Al L(-1) . Manure application rates were equivalent to approximately 125 kg N ha(-1) . Alum and aluminum chloride additions lowered soluble reactive phosphorus (SRP) levels from about 130 mg P L(-1) to approximately 30 mg P L(-1) at low rates . At high rates, SRP levels in swine manure were around 1 mg P L(-1) . Soluble reactive P concentrations in runoff were 5.50, 3.66, 3.00, 0.87, 0.87, and 0.55 mg P L(-1), for normal manure, low alum, low aluminum chloride, high alum, high aluminum chloride, and unfertilized control plots, respectively . Hence, high alum and aluminum chloride reduced SRP concentrations in runoff by 84% and were not statistically different from SRP concentrations in runoff from unfertilized control plots . These data indicate that treating swine manure with alum or aluminum chloride could result in significant reductions in nonpoint-source P runoff. J Environ Qual, 2001 May-Jun, 30(3), 1009 - 15 Phosphorus losses in furrow irrigation runoff; Westermann DT et al.; Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff . We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface-irrigated with Snake River water . Water-soluble P, Olsen P (inorganic and organic P), and iron-oxide impregnated paper-extractable P (FeO-Ps) were determined on a 0.03-m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999 . Dissolved reactive phosphorus (DRP) in a 0.45-microm filtered runoff sample, and iron-oxide impregnated paper-extractable P (FeO-Pw), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4-h irrigation on 18.3-m field plots . The 1998 and 1999 data sets were combined because there were no significant differences . Flow-weighted average runoff DRP and FeO-Pw concentrations increased linearly as all three soil P test concentrations increased . The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration . Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration . The average runoff total P concentration was 1.08 mg L(-1) at a soil Olsen P concentration of 10 mg kg(-1) . Soil erosion control will be necessary to reduce P losses in surface irrigation runoff. Environ Sci Pollut Res Int, 2001, 8(2), 95 - 102 Forest ecosystems and the changing patterns of nitrogen input and acid deposition today and in the future based on a scenario; Busch G et al.; A global assessment of the impact of the anthropogenic perturbation of the nitrogen and sulfur cycles on forest ecosystems is carried out for both the present-day {1980-1990} and for a projection into the future {2040-2050} under a scenario of economic development which represents a medium path of development according to expert guess {IPCC IS92a} . Results show that forest soils will receive considerably increasing loads of nitrogen and acid deposition and that deposition patterns are likely to change . The regions which are most prone to depletion of soils buffering capacity and supercritical nitrogen deposition are identified in the subtropical and tropical regions of South America and Southeast Asia apart from the well known 'hotspots' North-Eastern America and Central Europe . The forest areas likely to meet these two risks are still a minor fraction of the global forest ecosystems, though . But the bias between eutrophication and acidification will become greater and an enhanced growth triggered by the fertilizing effects of increasing nitrogen input cannot be balanced by the forest soils nutrient pools . Results show increasing loads into forest ecosystems which are likely to account for 46% higher acid loads and 36% higher nitrogen loads in relation to the 1980-1990 situation . Global background deposition of up to 5 kg N ha-1 a-1 will be exceeded at more than 25% of global forest ecosystems and at more than 50% of forest ecosystems on acid sensitive soils . More than 33% of forest ecosystems on acid sensitive soils will receive acid loads which exceeds their buffering capacity . About 25% of forest areas with exceeded acid loads will receive critical nitrogen loads. Environ Monit Assess, 2001 Jun, 69(1), 63 - 83 Stream phosphorus transport in the Lake Tahoe basin, 1989-1996; Hatch LK et al.; Lake Tahoe is undergoing the initial stages of cultural eutrophication due to human alteration of the airshed and watershed . The lake's switch from nitrogen (N) to phosphorus (P) limitation has been attributed primarily to atmospheric N loading . This places an increased importance on controlling watershed movement of P to the lake . A stream water quality monitoring data set consisting of nine streams in the Lake Tahoe basin has been analyzed to characterize the spatiotemporal variation of P delivery to the lake . This data is from the Lake Tahoe Interagency Monitoring Program (LTIMP), which provides scientific data for planning and regulatory agencies to address environmental problems in the Lake Tahoe basin . Results indicate that P delivery (concentrations, loads) varies greatly at interannual, seasonal, and spatial scales . Annual and seasonal total P (TP) concentrations can vary up to three orders of magnitude in a given stream and are strongly associated with suspended sediment . Particulate P is the major form of P transported by Tahoe streams and was strongly correlated with percent surficial geologic deposits, which are primarily located near streams . Tahoe streams with the highest annual P concentrations often had the lowest annual P loads, and visa versa . P loading is greatest during the spring snowmelt (75% of annual average) . Potential watershed parameters influencing P delivery to Lake Tahoe have been identified as precipitation, basin area, basin steepness, and road and human development coverage . Results also suggest that human development impacts on stream P loads are most prevalent during high precipitation years . Identification and quantification of stream sediment and P sources such as streambanks and impervious surface is necessary to aid in watershed restoration efforts. Environ Monit Assess, 2001 May, 68(3), 297 - 312 Marine eutrophication: a proposed data analysis procedure for assessing spatial trends; Kitsiou D et al.; A methodology for the discrimination of the different trophic levels at a spatial scale in the marine environment is proposed using spatial analysis methods and non-parametric statistics . Phytoplankton cell number, being a representative parameter to express trophic trends in the marine ecosystem is selected for the methodology development; Saronicos Gulf, Greece is used for the case study . The proposed stepwise methodology includes interpolation for assessing the spatial distribution of phytoplankton cell number, division of the Gulf into a number of quadrates, development of a scale characterising trophic levels and finally characterisation of the trophic state of each quadrate using non-parametric statistics . The advantages of this methodology and the potential applications in coastal management studies are also discussed. Huan Jing Ke Xue, 2001 Jan, 22(1), 98 - 101 {Phosphorus loss potential of soil-water in sites of the main rice-yield area in the Northern Zhejiang}; Zhang Z et al.; Phosphorus (P) loss potential and its environmental impact from soil-water were surveyed in Jiashan Yuyao, Deqing and Yuhang, named main rice-yield areas in Northern Zhejiang province China . High P input has resulted in soil P accumulation . Higher soil Olsen-P contributed its bio-available P, water extracted P and increased soil P loss potential . The role of P in paddy soils is of environmental rather than agronomic concern in the process of soil P build-up . During the no-rice time, total P (TP) concentration in the various water including ditch drain inside/outside field, field surface water and pipe drain et al are over the critical values associated with accelerated waters eutrophication . The average proportion of dissolved reactive P (DRP) concentration in TP was 40%, however, these current DRP levels in partly ditch drain outside field and surface or ground water in no-rice time could not caused serious impact to the outside waters nearby rice-yield agriculture area . No significant line correlation between soil P tests and P in field surface water was found in no-rice time due to differences in field tillage among rice-yield areas, while P application increased both soil P and its correspondingly field surface P level after rice was planted at the same time. Mar Pollut Bull, 2001 Feb, 42(2), 87 - 90 Ospar 98/3: an environmental turning point or a flawed decision? Bellamy D, Wilkinson P. While the problems of over-fishing and eutrophication continue largely unchecked, the Ospar Commission, which exists to improve the quality of European seas, requires governments, the public and the oil companies to find 20 billion Pounds to remove millions of tons of steel to demonstrate its commitment to the mantra that 'the seas are not dustbins' . The decision, taken in 1998, was made despite a paucity of evidence to identify the environmental impact redundant rigs create, despite the absence of scientific support to demonstrate that removal is the best practicable environmental option and in the knowledge that the decision had more to do with a green anti-oil agenda than with improving marine quality . It may be shown in the fullness of time not to be in the best interests of the environment . Moreover, and perhaps more importantly, the manner in which the decision was made is lacking in important respects. Mar Pollut Bull, 2001 Feb, 42(2), 149 - 56 A new approach for detecting and mapping sewage impacts; Costanzo SD et al.; Increased nitrogen loading has been implicated in eutrophication occurrences worldwide . Much of this loading is attributable to the growing human population along the world's coastlines . A significant component of this nitrogen input is from sewage effluent, and delineation of the distribution and biological impact of sewage-derived nitrogen is becoming increasingly important . Here, we show a technique that identifies the source, extent and fate of biologically available sewage nitrogen in coastal marine ecosystems . This method is based on the uptake of sewage nitrogen by marine plants and subsequent analysis of the sewage signature (elevated delta 15N) in plant tissues . Spatial analysis is used to create maps of delta 15N and establish coefficient of variation estimates of the mapped values . We show elevated delta 15N levels in marine plants near sewage outfalls in Moreton Bay, Australia, a semi-enclosed bay receiving multiple sewage inputs . These maps of sewage nitrogen distribution are being used to direct nutrient reduction strategies in the region and will assist in monitoring the effectiveness of environmental protection measures. Water Sci Technol, 2001, 43(5), 269 - 76 Characteristics of primary production in a eutrophicated bay; Nakashima M et al.; The primary production of phytoplanktons provides organic matter in high concentration in eutrophicated Hakata bay in Japan, even during the winter season in spite of low water temperature . Phytoplanktons may have the biological capabilities to maintain activities of photosynthesis under unfavorable conditions, and these capabilities affect water quality in the bays . In this study, characteristics of primary production were analyzed with a simple box-type ecosystem model . We introduced a concept of efficiency for absorption of sunlight energy to our simulation model of water quality to explain rather high growth rates of phytoplanktons in low sunlight intensity . Through simulation with a box model, we found that the efficiency of primary production in winter is higher than that in summer . It was suggested that the organic pollution comes from dissolved organic carbon (DOC) throughout the year and that the DOC is originated from the primary production of phytoplanktons in biological response of the seasonal change of ambient conditions. East Mediterr Health J, 2000 Jan, 6(1), 106 - 17 Marib Dam: the importance of environmental and health impact studies for development projects; Basahi IA; Marib Dam was built without an environmental impact assessment study which created many conflicts . In 1995 and 1996 its impact on water quality, agriculture and groundwater recharge and socioeconomics was studied . Lake water could suffer severe eutrophication when floods are weak and algae growth is not controlled . Introducing Tilapia nilotica provided biological control of algae growth . The dam positively affected agriculture and groundwater within the designed irrigation scheme but negatively affected them beyond it . The dam also negatively affected health conditions and increased conflicts over water distribution . It positively affected women by allowing them to work in agriculture and participate in decision-making . The dam raised income levels of farmers and encouraged tourism. Environ Pollut, 2001, 113(1), 95 - 107 Complex interactions between autotrophs in shallow marine and freshwater ecosystems: implications for community responses to nutrient stress; Havens KE et al.; The relative biomass of autotrophs (vascular plants, macroalgae, microphytobenthos, phytoplankton) in shallow aquatic ecosystems is thought to be controlled by nutrient inputs and underwater irradiance . Widely accepted conceptual models indicate that this is the case both in marine and freshwater systems . In this paper we examine four case studies and test whether these models generally apply . We also identify other complex interactions among the autotrophs that may influence ecosystem response to cultural eutrophication . The marine case studies focus on macroalgae and its interactions with sediments and vascular plants . The freshwater case studies focus on interactions between phytoplankton, epiphyton, and benthic microalgae . In Waquoit Bay, MA (estuary), controlled experiments documented that blooms of macroalgae were responsible for the loss of eelgrass beds at nutrient-enriched locations . Macroalgae covered eelgrass and reduced irradiance to the extent that the plants could not maintain net growth . In Hog Island Bay, VA (estuary), a dense lawn of macroalgae covered the bottom sediments . There was reduced sediment-water nitrogen exchange when the algae were actively growing and high nitrogen release during algal senescence . In Lakes Brobo (West Africa) and Okeechobee (FL), there were dramatic seasonal changes in the biomass and phosphorus content of planktonic versus attached algae, and these changes were coupled with changes in water level and abiotic turbidity . Deeper water and/or greater turbidity favored dominance by phytoplankton . In Lake Brobo there also was evidence that phytoplankton growth was stimulated following a die-off of vascular plants . The case studies from Waquoit Bay and Lake Okeechobee support conceptual models of succession from vascular plants to benthic algae to phytoplankton along gradients of increasing nutrients and decreasing under-water irradiance . The case studies from Hog Island Bay and Lake Brobo illustrate additional effects (modified sediment-water nutrient fluxes, allelopathy or nutrient release during plant senescence) that could play a role in ecosystem response to nutrient stress. Proc Natl Acad Sci U S A, 2001 May 8, 98(10), 5411 - 8 What was natural in the coastal oceans? Jackson JB. Humans transformed Western Atlantic coastal marine ecosystems before modern ecological investigations began . Paleoecological, archeological, and historical reconstructions demonstrate incredible losses of large vertebrates and oysters from the entire Atlantic coast . Untold millions of large fishes, sharks, sea turtles, and manatees were removed from the Caribbean in the 17th to 19th centuries . Recent collapses of reef corals and seagrasses are due ultimately to losses of these large consumers as much as to more recent changes in climate, eutrophication, or outbreaks of disease . Overfishing in the 19th century reduced vast beds of oysters in Chesapeake Bay and other estuaries to a few percent of pristine abundances and promoted eutrophication . Mechanized harvesting of bottom fishes like cod set off a series of trophic cascades that eliminated kelp forests and then brought them back again as fishers fished their way down food webs to small invertebrates . Lastly, but most pervasively, mechanized harvesting of the entire continental shelf decimated large, long-lived fishes and destroyed three-dimensional habitats built up by sessile corals, bryozoans, and sponges . The universal pattern of losses demonstrates that no coastal ecosystem is pristine and few wild fisheries are sustainable along the entire Western Atlantic coast . Reconstructions of ecosystems lost only a century or two ago demonstrate attainable goals of establishing large and effective marine reserves if society is willing to pay the costs . Historical reconstructions provide a new scientific framework for manipulative experiments at the ecosystem scale to explore the feasibility and benefits of protection of our living coastal resources. Environ Toxicol Chem, 2001 May, 20(5), 996 - 1002 Influence of salinity and eutrophication on bioaccumulation of 99technetium in duckweed; Hattink J et al.; This study concerns the bioaccumulation of the long-lived nuclear waste product 99Tc in duckweed (Lemna minor L.) . 99Tc was present as the oxyanion TcO4-, being the main chemical form of technetium in aerobic water systems . In contrast with terrestrial plants, bioaccumulation in duckweed proved to be independent of the nitrate concentration in the medium . However, uptake is controlled by electrostatic effects in the cell wall, which affects the bioaccumulation of 99Tc in duckweed in natural environments . These waters are characterized by a range of salinity and hardness, and this study suggests that this may result in up to a threefold difference in 99Tc accumulation . Because of screening of negative charges in the cell wall, the highest accumulation may be expected in hard, brackish water . This behavior can be described by a general model, which includes electrostatic effects and binding of cations at the cell wall . The model also explains why cationic radionuclides are preferably taken up in soft, fresh water while anionic species are concomitantly taken up in hard, chlorine-rich waters. Science, 2001 Apr 13, 292(5515), 281 - 4 Forecasting agriculturally driven global environmental change; Tilman D et al.; During the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by a wealthier and 50% larger global population will be a major driver of global environmental change . Should past dependences of the global environmental impacts of agriculture on human population and consumption continue, 10(9) hectares of natural ecosystems would be converted to agriculture by 2050 . This would be accompanied by 2.4- to 2.7-fold increases in nitrogen- and phosphorus-driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems, and comparable increases in pesticide use . This eutrophication and habitat destruction would cause unprecedented ecosystem simplification, loss of ecosystem services, and species extinctions . Significant scientific advances and regulatory, technological, and policy changes are needed to control the environmental impacts of agricultural expansion. J Environ Qual, 2001 Mar-Apr, 30(2), 387 - 94 Greenhouse gases in non-oxygenated and artificially oxygenated eutrophied lakes during winter stratification; Huttunen JT et al.; Concentrations of dissolved methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) were measured in the water columns of non-oxygenated and artificially oxygenated, ice-covered eutrophied lakes in the mid-boreal zone in Finland during late winter 1997 and 1999 . Sampling was conducted during winter stratification, the critical period for oxygen (O2) deficiency in seasonally ice-covered, thermally stratified lakes . Oxygen concentrations were maintained at least at a moderate level throughout the oxygenated water columns, whereas the non-oxygenated columns suffered anoxic hypolimnia . The mean concentrations of dissolved CH4 exceeding the atmospheric equilibrium were greater in the non-oxygenated water columns (20.6-154 microM) than in the oxygenated ones (0.01-1.41 microM) . In contrast, the mean excess CO2 concentrations varied less between the non-oxygenated and oxygenated sites (0.28-0.47 and 0.25-0.31 mM, respectively) . Oxygenated water columns had greater mean excess concentrations of N2O (0.018-0.032 microM) than the non-oxygenated ones (0.005-0.024 microM) . If the accumulated greenhouse gas stores in the water columns during winter are assumed to be released to the atmosphere during the spring overturn, the global warming potentials (GWP, time horizon 100 yr) of these potential emissions at the non-oxygenated, eutrophic study sites ranged from 177 to 654 g CO2 equivalent (CO2-e) m-2 compared with 144 to 173 g CO2-e m-2 at the oxygenated sites . The increase in the accumulation of CH4 was the main reason for the higher GWP of the non-oxygenated sites . Anthropogenic eutrophication of lake ecosystems can generate increased CH4 emissions due to associated O2 depletion of their sediment and water column. J Environ Qual, 2001 Mar-Apr, 30(2), 320 - 9 Hypoxia in the Gulf of Mexico; Rabalais NN et al.; Seasonally severe and persistent hypoxia, or low dissolved oxygen concentration, occurs on the inner- to mid-Louisiana continental shelf to the west of the Mississippi River and Atchafalaya River deltas . The estimated areal extent of bottom dissolved oxygen concentration less than 2 mg L-1 during mid-summer surveys of 1993-2000 reached as high as 16,000 to 20,000 km2 . The distribution for a similar mapping grid for 1985 to 1992 averaged 8000 to 9000 km2 . Hypoxia occurs below the pycnocline from as early as late February through early October, but is most widespread, persistent, and severe in June, July, and August . Spatial and temporal variability in the distribution of hypoxia exists and is, at least partially, related to the amplitude and phasing of the Mississippi and Atchafalaya discharges and their nutrient flux . Mississippi River nutrient concentrations and loadings to the adjacent continental shelf have changed dramatically this century, with an acceleration of these changes since the 1950s to 1960s . An analysis of diatoms, foraminiferans, and carbon accumulation in the sedimentary record provides evidence of increased eutrophication and hypoxia in the Mississippi River delta bight coincident with changes in nitrogen loading. J Environ Qual, 2001 Mar-Apr, 30(2), 303 - 20 Chesapeake Bay eutrophication: scientific understanding, ecosystem restoration, and challenges for agriculture; Boesch DF et al.; Chesapeake Bay has been the subject of intensive research on cultural eutrophication and extensive efforts to reduce nutrient inputs . In 1987 a commitment was made to reduce controllable sources of nitrogen (N) and phosphorous (P) by 40% by the year 2000, although the causes and effects of eutrophication were incompletely known . Subsequent research, modeling, and monitoring have shown that: (i) the estuarine ecosystem had been substantially altered by increased loadings of N and P of approximately 7- and 18-fold, respectively; (ii) hypoxia substantially increased since the 1950s; (iii) eutrophication was the major cause of reductions in submerged vegetation; and (iv) reducing nutrient sources by 40% would improve water quality, but less than originally thought . Strong public support and political commitment have allowed the Chesapeake Bay Program to reduce nutrient inputs, particularly from point sources, by 58% for P and 28% for N . However, reductions of nonpoint sources of P and N were projected by models to reach only 19% and 15%, respectively, of controllable loadings . The lack of reductions in nutrient concentrations in some streams and tidal waters and field research suggest that soil conservation-based management strategies are less effective than assumed . In 1997, isolated outbreaks of the toxic dinoflagellate Pfiesteria piscicida brought attention to the land application of poultry manure as a contributing factor to elevated soil P and ground water N concentrations . In addition to developing more effective agricultural practices, emerging issues include linking eutrophication and living resources, reducing atmospheric sources of N, enhancing nutrient sinks, controlling sprawling suburban development, and predicting and preventing harmful algal blooms. J Environ Qual, 2001 Mar-Apr, 30(2), 275 - 81 Overview of hypoxia around the world; Diaz RJ; No other environmental variable of such ecological importance to estuarine and coastal marine ecosystems around the world has changed so drastically, in such a short period of time, as dissolved oxygen . While hypoxic and anoxic environments have existed through geological time, their occurrence in shallow coastal and estuarine areas appears to be increasing, most likely accelerated by human activities . Several large systems, with historical data, that never reported hypoxia at the turn of the 19th century (e.g., Kattegat, the sea between Sweden and Denmark) now experience severe seasonal hypoxia . Synthesis of literature pertaining to benthic hypoxia and anoxia revealed that the oxygen budgets of many major coastal ecosystems have been adversely affected mainly through the process of eutrophication (the production of excess organic matter) . It appears that many ecosystems that are now severely stressed by hypoxia may be near or at a threshold of change or collapse (loss of fisheries, loss of biodiversity, alteration of food webs). Environ Monit Assess, 2001 Feb, 66(3), 265 - 79 Comparative studies on the usefulness of seven ecological indices for the marine coastal monitoring close to the shore on the Swedish East coast; Danilov RA et al.; The simultaneous behaviour of seven ecological indices (Hurlbert's, Margalef's, Menhinick's, Shannon's, species number, Jaccard's and saprobic index) was studied based on phytoplankton data close to the shore on the East coast of Sweden during the summer 1998 . The sampling stations had a similar eutrophication level and were located in bays . Standard phytoplankton databases were used in calculating the indices, which were later compared using cluster analysis . Hurlbert's, Margalef's, Menhinick's, Shannon's and species number indices, as measure of community diversity, produced similar trends which often differed from those based on Jaccard's index of similarity . However, the simultaneous use of these indices was found meaningful as a possible part of the monitoring close to the shore . The application of a saprobic index lead to erroneous conclusions in the studied case. Int J Occup Med Environ Health, 2000, 13(4), 335 - 44 Apoptotic effect of cyanobacterial blooms collected from Polish water reservoirs; Mankiewicz J et al.; Recently in many countries, including Poland, the problem of toxicity of cyanobacterial blooms has been of great importance . In many cases it is connected with the increase of microcystins (MCYSTs) concentration in fresh water . This problem is caused by excessive eutrophication of drinking and recreational water bodies . In humans, the most frequent symptoms of the MCYST effect are: cutaneous rash, fever, vomiting, diarrhoea, gastroenteritis and acute damage of the liver . The aim of this work was to estimate apoptotic effects of five different cyanobacterial hepatotoxic extracts containing MC-LR and other variants of MCYSTs (MC-RR, MC-YR, and MC-WR) . These effects were analysed in rat hepatocytes--primary target of cyanobacterial hepatotoxins . Morphological changes in hepatocytes were examined by means of fluorescence and differential interference contrast microscopy with the DNA-specific dye, Hoechst 33342 . The hepatocytes were treated with each cyanobacterial extracts containing MC-LR in the range between 100 nM-2000 nM for 30 min, 60 min and 120 min . The first characteristic apoptotic changes: shrinking and budding of cells were seen after 30 min, MC-LR = 100 nM . During the next 30 min the percentage of apoptotic cells increased by over 50%, MC-LR at concentrations ranging from 100 to 250 nM (the value dependent on a bloom sample) . Highly condensed chromatin and apoptotic bodies were observed in 85-90% of hepatocytes after 120 min of treatment with MC-LR in concentration of 1000 nM . The apoptotic changes in rat hepatocytes confirm the high cytotoxic potential of cyanobacterial bloom samples collected during different months and years from reservoirs of drinking and recreational water in central Poland. Aquat Toxicol, 2001 Jun, 53(1), 19 - 32 DNA integrity and total oxyradical scavenging capacity in the Mediterranean mussel, Mytilus galloprovincialis: a field study in a highly eutrophicated coastal lagoon; Frenzilli G et al.; In Mediterranean coastal lagoons, the combination of human impact and wide variability of natural environmental factors can lead to upsets in ecosystem homeostasis resulting in biodiversity decline . Oxidative damage has been causally linked to various kinds of environmental stress, both natural and artificial, the result being impairment of cellular functions . DNA damage and the efficiency of antioxidant defences in Mytilus galloprovincialis from the highly eutrophicated Orbetello Lagoon (Tuscany, Italy) were investigated, respectively by the single cell gel electrophoresis (or Comet test) and the total oxyradical scavenging capacity assay . Results showed significantly higher levels of DNA damage in mussels collected from the inner parts of the lagoon compared to specimens from more external sites . Specimens with the lower genetic integrity also exhibited a reduced efficiency in neutralizing three potent cellular oxidizing species, namely peroxyl radicals (ROO*), hydroxyl radicals (*OH) and peroxynitrite (HOONO), suggesting the involvement of reactive oxygen species in mediating the genetic damage . The analyzed biological parameters also showed a seasonal variability with a minimum of both DNA integrity and antioxidant scavenging efficiency during the warm months and an opposite trend in winter . The potential of analyzed techniques is discussed for the assessment of both anthropogenic and natural disturbance. Water Res, 2001 Mar, 35(3), 729 - 35 Factors influencing lake recovery from eutrophication--the case of basin 1 of Lake Balaton; Istvanovics V et al.; Lake Balaton is a large, shallow, and calcareous lake that was subject to a rapid eutrophication during the 1970s . Management measures taken from the mid-1980s decreased the phosphorus load to the lake from 0.5 to 0.3 g P m-2 yr-1 . Using long-term load and water quality data, we analyse the response of the formerly hypertrophic Basin 1 of the lake by the means of simple empirical models . Several factors that are commonly neglected during studies of lake recovery modified the apparent settling velocity of total P and consequently, the biomass of the phytoplankton . These factors included the loads of calcium and suspended solids, the loading ratio of the dissolved to particulate phosphorus, and blooming of the dominant cyanobacterium, Cylindrospermopsis raciborskii . Due to the rapid immobilisation of the mobile phosphorus in the surface sediments, moderate reduction (45-50%) in the external load resulted in a surprisingly fast and significant improvement of the water quality in the hypertrophic southwestern basins of the lake. J Environ Qual, 2001 Jan-Feb, 30(1), 160 - 70 Biosolids application in the Chihuahuan desert: effects on runoff water quality; Rostagno CM et al.; Surface-applied biosolids, the option most often used on range-lands, can increase the concentration of macronutrients and trace elements in the runoff water and can potentially produce eutrophication or contamination of surface waters . In this study, the effects of postapplication age of biosolids (18, 12, 6, and 0.5 mo) and rate of application (0, 7, 18, 34, and 90 Mg ha(-1)) on the quality of runoff water from shrubland and grassland soils were assessed . Between July and October 1996 simulated rainfall was applied to 0.50-m2 plots for 30 min at a rate of 160 mm h(-1) . All of the runoff water was collected . The concentration of NH4+ -N, NO3- -N, PO4(3-)-P, total dissolved phosphorus (TDP), Cu, and Mn in the runoff water increased with rate of biosolids application and decreased with time of postapplication on the two soils . The highest PO4(3-)-P and NH4+ -N concentrations, 4.96 and 97 mg L(-1), respectively, were recorded in the grassland soil treated with 90 Mg ha(-1) of biosolids 0.5 mo postapplication . For the same soil, rate, and postapplication age of biosolids, Cu exceeded the upper limit (0.50 mg L(-1) in drinking water for livestock . Ammonium N and PO4(3-)-P should be the main compounds considered when surface-applying biosolids . Ammonium N at concentrations found in all biosolids-treated plots may affect the quality of livestock drinking water by causing taste and smell problems . Orthophosphate can contribute to eutrophication if the runoff from biosolids-treated areas enter surface waters. Sci Total Environ, 2001 Jan 17, 264(3), 235 - 40 Marine dinoflagellate cysts as indicators of eutrophication and industrial pollution: a discussion; Dale B; The results from an investigation of dinoflagellate cysts as indicators of eutrophication in Tokyo Bay, Japan, by Matsuoka {Sci Total Environ 231 (1999) 17} are discussed with reference to other pertinent literature not discussed in the original article . Both the Japanese study and previous work from Norwegian fjords show that pollution (including cultural eutrophication) may produce changes in the phytoplankton reflected by a shift from more autotrophic--to more heterotrophic--dominance of cyst assemblages . However, this is a proportional change that seems likely to result from reduced autotrophic production rather than the increased heterotrophic production suggested by Matsuoka . This is not unequivocal evidence of eutrophication, since Tokyo Bay is impacted also by heavy industrial pollution, the possible effects of which cannot be distinguished, and the quantitative method used for estimating changes in cyst productivity is flawed. Environ Pollut, 2001, 111(2), 263 - 72 Nutrient dynamics and the eutrophication of shallow lakes Kasumigaura (Japan), Donghu (PR China), and Okeechobee (USA); Havens KE et al.; We compared the nutrient dynamics of three lakes that have been heavily influenced by point and non-point source pollution and other human activities . The lakes, located in Japan (Lake Kasumigaura), People's Republic of China (Lake Donghu), and the USA (Lake Okeechobee), all are relatively large (> 30 km2), very shallow (< 4 m mean depth), and eutrophic . In all three lakes we found strong interactions among the sediments, water column, and human activities . Important processes affecting nutrient dynamics included nitrogen fixation, light limitation due to resuspended sediments, and intense grazing on algae by cultured fish . As a result of these complex interactions, simple empirical models developed to predict in-lake responses of total phosphorus and algal biomass to external nutrient loads must be used with caution . While published models may provide 'good' results, in terms of model output matching actual data, this may not be due to accurate representation of lake processes in the models . The variable nutrient dynamics that we observed among the three study lakes appears to be typical for shallow lake systems . This indicates that a greater reliance on lake-specific research may be required for effective management, and a lesser role of inter-lake generalization than is possible for deeper, dimictic lake systems . Furthermore, accurate predictions of management impacts in shallow eutrophic lakes may require the use of relatively complex deterministic modeling tools. Environ Pollut, 2001, 112(1), 53 - 60 Nutrient losses by surface run-off following the application of organic manures to arable land . 2 . Phosphorus; Smith KA et al.; Phosphorus (P) surface run-off losses were studied following organic manure applications to land, utilising a purpose-built facility on a sloping site in Herefordshire under arable tillage . Different rates and timing of cattle slurry, farm yard manure (FYM) and inorganic nitrogen (N) and P fertiliser were compared, over a 4-year period (1993-97) . N losses from the same studies are reported in a separate paper . The application of cattle FYM and, especially slurry, to the silty clay loam soil increased both particulate and soluble P loss in surface water flow . Losses via subsurface flow (30 cm interflow) were consistently much lower than via surface water movement and were generally unaffected by treatment . Increased application of slurry solids increased all forms of P loss via surface run-off; the results suggested that a threshold for greatly increased risk of P losses via this route, as for N, occurred at ca . 2.5-3.0 t/ha solids loading . This approximates to the 50 m3/ha application rate limit suggested for slurry within UK 'good agricultural practice' . The studies also provided circumstantial evidence of the sealing of the soil surface by slurry solids as the major mechanism by which polluting surface run-off may occur following slurry application on susceptible soils . Losses of total and soluble P, recorded for each of the 4 years of experiments, reached a maximum of only up to 2 kg/ha total P (TP), even after slurry applications initiating run-off . Whilst these losses are insignificant in agronomic terms, peak concentrations of P (up to 30,000 micrograms/l TP) in surface water during a run-off event, could be of considerable concern in sensitive catchments . Losses of slurry P via surface run-off could make a significant contribution to accelerated eutrophication on entry to enclosed waters, particularly when combined with high concentrations of NO3(-)-N . Restricting slurry application rates to those consistent with good agronomic practice, and within the limits specified in existing guidelines on good agricultural practice, offers the simplest and most effective control measure against this potentially important source of diffuse pollution. Environ Pollut, 2001, 112(1), 41 - 51 Nutrient losses by surface run-off following the application of organic manures to arable land . 1 . Nitrogen; Smith KA et al.; Research was conducted on nitrogen (N) surface run-off losses following organic manure applications to land, utilising a purpose-built facility on a sloping site in Herefordshire under arable tillage . Different rates and timing of cattle slurry, farmyard manure and inorganic N and phosphorus (P) fertiliser were compared, over a 4-year period (1993-97) . P losses from the same studies are reported in a separate paper . The application of cattle slurries to the silty clay loam soil increased the loss of solids and NH4(+)-N in surface water flow compared to control plots receiving inorganic fertiliser only, or no treatment, but had little effect on NO3(-)-N losses by this route . Results were consistent with other observations that rainfall events immediately after manure applications are particularly likely to be associated with nutrient run-off losses . Losses via subsurface flow (30 cm interflow) were consistently much lower than via surface water movement and were generally unaffected by treatment . Increasing slurry application rate and, in particular, slurry solids loading, increased solids and NH4(-)-N losses via surface run-off . The threshold, above which the risk of losses via surface run-off appeared to be greatly increased, was ca . 2.5-3.0 t/ha slurry solids, which approximates to the 50 m3/ha limit suggested for slurry within UK 'good agricultural practice' . Sealing of the soil surface by slurry solids appears to be a possible mechanism by which polluting surface run-off may occur following slurry application on susceptible soils . Total losses of NH4(+)-N and NO3(-)-N during the 4-year monitoring period were insignificant in agronomic terms, but average soluble N concentrations (NH4(+)-N + NO3(-)-N) in run-off, ranging from ca . 2.0 mg/l, up to 14.0 mg/l for the higher rate slurry treatments . Peak concentrations of NH4(+)-N > 30 mg/l, are such as to be of concern in sensitive catchments, in terms of the potential for contribution to accelerated eutrophication and adverse effects on freshwater biota. Toxicology, 2000 Nov 16, 153(1-3), 61 - 72 Applications and pitfalls of stress-proteins in biomonitoring; Bierkens JG; The vast number of potentially hazardous chemicals and the complex interactions that can occur between them in environmental mixtures, call for inexpensive, early and sensitive endpoints that reflect their biological effect . The existing validated bioassays, mostly based on lethality or reproduction, have been shown to be inadequate in respect of their sensitivity, the duration and expense of the test . In contrast, changes at biochemical level are usually the first detectable responses to environmental perturbation . Because these alterations underlie all effects at higher organisational level, they have often been shown to be very sensitive indicators of pollution . Stress-proteins (also referred to as heat-shock proteins or hsp) have recently been recognised as being one of the primary defence mechanisms that are activated by the occurrence of denatured proteins in the cell . Four major stress-protein families of 90,70,60 and 16-24 kDa are the most prominent and are frequently referred to as hsp90, hsp70, hsp60 and low molecular weight (LMW) stress-proteins . Three aspects of stress-proteins have been characterised that are essential if they want to be used as biomarkers of pollution: (1) they are part of the cellular protective response; (2) their synthesis is likely to be induced by a large number of chemicals; and (3) they are highly conserved in all organisms from bacteria to plants and man . Also, field studies have shown (be it for a limited number of stressors) that the stress response can occur even at the minute concentrations of pollutants that are usually found in the environment . However, increasing knowledge on the kinetics and persistence of the stress response to complex environmental mixtures, on the influence of both physiological and environmental parameters (pH, eutrophication, ellipsis), on the constitutive levels of stress-proteins and on the acquisition of tolerance, is required before one could safely apply stress-proteins to assess on-site pollution . Still, included in a test battery of complementary bioassays, stress protein may be very valuable as tier I biomarkers, i.e . broad response biomarkers that are used for preliminary screening of the environment. Int J Food Microbiol, 2000 Nov 1, 61(2-3), 91 - 125 Ciguatera: recent advances but the risk remains; Lehane L et al.; Ciguatera is an important form of human poisoning caused by the consumption of seafood . The disease is characterised by gastrointestinal, neurological and cardiovascular disturbances . In cases of severe toxicity, paralysis, coma and death may occur . There is no immunity, and the toxins are cumulative . Symptoms may persist for months or years, or recur periodically . The epidemiology of ciguatera is complex and of central importance to the management and future use of marine resources . Ciguatera is an important medical entity in tropical and subtropical Pacific and Indian Ocean regions, and in the tropical Caribbean . As reef fish are increasingly exported to other areas, it has become a world health problem . The disease is under-reported and often misdiagnosed . Lipid-soluble, polyether toxins known as ciguatoxins accumulated in the muscles of certain subtropical and tropical marine finfish cause ciguatera . Ciguatoxins arise from biotransformation in the fish of less polar ciguatoxins (gambiertoxins) produced by Gambierdiscus toxicus, a marine dinoflagellate that lives on macroalgae, usually attached to dead coral . The toxins and their metabolites are concentrated in the food chain when carnivorous fish prey on smaller herbivorous fish . Humans are exposed at the end of the food chain . More than 400 species of fish can be vectors of ciguatoxins, but generally only a relatively small number of species are regularly incriminated in ciguatera . Ciguateric fish look, taste and smell normal, and detection of toxins in fish remains a problem . More than 20 precursor gambiertoxins and ciguatoxins have been identified in G . toxicus and in herbivorous and carnivorous fish . The toxins become more polar as they undergo oxidative metabolism and pass up the food chain . The main Pacific ciguatoxin (P-CTX-1) causes ciguatera at levels=0.1 microg/kg in the flesh of carnivorous fish . The main Caribbean ciguatoxin (C-CTX-1) is less polar and 10-fold less toxic than P-CTX-1 . Ciguatoxins activate sodium ion (Na ) channels, causing cell membrane excitability and instability . Worldwide coral bleaching is now well documented, and there is a strong association between global warming and the bleaching and death of coral . This, together with natural environmental factors such as earthquakes and hurricanes, and man-made factors such as tourism, dock construction, sewage and eutrophication, may create more favourable environments for G . toxicus . While low levels of G . toxicus are found throughout tropical and subtropical waters, the presence of bloom numbers is unpredictable and patchy . Only certain genetic strains produce ciguatoxins, and environmental triggers for increasing toxin production are unknown. Rev Bras Biol, 2000 May, 60(2), 229 - 236 Uptake rates of nitrogen and phosphorus in the water by Eichhornia crassipes and Salvinia auriculata; Petrucio MM et al.; The main goal of this research was to survey information about the physiology of Eichhornia crassipes and Salvinia auriculata and their capacity to remove nitrogen and phosphorus from the environment, after quantifying the concentrations of the nitrogen (NO3-N, NH4-N and total-N) and phosphorus (PO4-P and total-P) compounds in the water . The macrophytes were incubated in the laboratory in plastic vials of approximately 1.5 litters containing a previously prepared solution of NH4NO3, NH4Cl and KH2PO4 . Eichhornia crassipes exhibited the highest rates of nutrient reduction and the concentrations of NO3-N, NH4-N and PO4-P in the water influenced the uptake rates of nitrogen and phosphorus of the E . crassipes and S . auriculata . This information can help to reach adequate management strategies for aquatic macrophytes in order to reduce the eutrophication process in Imboassica lagoon. Comp Biochem Physiol B Biochem Mol Biol, 2000 Apr, 125(4), 457 - 71 Sulphide detoxification in Hediste diversicolor and Marenzelleria viridis, two dominant polychaete worms within the shallow coastal waters of the southern Baltic Sea; Hahlbeck E et al.; The polychaete worms Marenzelleria viridis (Verrill 1873) and Hediste diversicolor (O.F . Muller) form the main part of the macro-zoobenthos in soft-bottomed shallow inlets of the Baltic Sea . Due to high eutrophication within these waters the animals are exposed to low oxygen and high sulphide concentrations . Specimens of both species from a low salinity location (S 8/1000) were compared concerning their physiological abilities in coping with this hostile environment . Sulphide detoxification occurred in both polychaetes even during severe hypoxia with the main end-product being thiosulphate . In absence of sulphide nearly no end-products of anaerobic metabolism were found in the worms during moderate hypoxia (pO2 = 7 kPa) . In presence of hydrogen sulphide, succinate, a sensitive indicator of anaerobic metabolism, was accumulated in higher amounts at low sulphide concentrations (0.3 mM) already . Oxygen consumption and ATP production was determined in isolated mitochondria of both species . Both polychaetes were able to perform enzymatic sulphide oxidation in the mitochondria at concentrations up to 50 microM . This process was coupled with oxidative phosphorylation . At least in M . viridis sulphide respiration was not completely inhibited by cyanide, suggesting an alternative oxidation pathway, which by-passes the cytochrome-c-oxidase . The two species did not differ in the rate of sulphide detoxification, but H . diversicolor produced about as twice as much ATP from mitochondrial sulphide oxidation . Differences in mitochondrial sulphide oxidation are probably related to the different life strategies of the worms. Sci Total Environ, 2000 Jun 8, 255(1-3), 113 - 27 Categorical mapping of marine eutrophication based on ecological indices; Kitsiou D et al.; The present work is concerned with the development of methodological procedures for studying the spatial distribution of eutrophication in the marine environment . Seven ecological indices (S, number of phytoplankton species; N, total number of individuals; D(Mg), Margalef's index; D(Mn), Menhinick's index; D(Od), Odum's species per thousand individuals; H', Shannon's Diversity index; E, Evenness index), based on phytoplankton community data collected from Saronicos Gulf, Greece were used for describing the eutrophication state of the sea environment . A representation of the spatial distribution for each ecological index was developed using the Inverse Distance Weighted (IDW) interpolation method . A eutrophication scale for each index was also developed for indicating four different trophic levels in the marine environment (eutrophic, upper-mesotrophic, lower-mesotrophic, oligotrophic); categorization of the interpolated values of each index resulted in a clear illustration of these trophic levels on seven thematic maps . Two methodological procedures were finally applied for synthesizing the information of these thematic maps . The purpose was the development of a final map illustrating the spatial distribution of eutrophication in the study area . The first procedure was based on the integration of unsupervised and supervised classification methods, widely used in the field of remote sensing, while the second one on the overlay technique, simply carried out within the frame of a Geographical Information System (GIS) . The hybrid unsupervised/supervised classification method can assess the optimal number of classes in which data values from simultaneously considered parameters could be allocated, while the overlay technique is an additive procedure not taking into account existing trends in the dataset . The advantages and disadvantages of each procedure are further discussed. Toxicon, 2000 Dec, 38(12), 1759 - 71 Isolation and characterization of microcystins from a river nile strain of Oscillatoria tenuis Agardh ex Gomont; Brittain S et al.; The River Nile is the major source of drinking water in Egypt, however, increased eutrophication due to agricultural, municipal and industrial runoff has contributed to the growth of toxin producing cyanobacteria . This study describes the isolation and characterization of microcystins (MCYSTs), cyclic heptapeptide hepatotoxins, from a rare strain of Oscillatoria tenuis, isolated from the River Nile at Sohag province in July 1995 . The MCYST concentration of laboratory-cultured O . tenuis strain E6 was found to be 0.3 mg/g freeze-dried weight determined by enzyme-linked immunosorbent assay (ELISA) . Two microcystins, 1 and 2, were isolated from lyophilized cells using solid phase extraction and reversed-phase high performance liquid chromatography (HPLC) . Structures were assigned based upon their amino acid analyses, electrospray ionization mass spectrometry (ESIMS, ESIMS-CID-MS), high resolution fast atom bombardment mass spectrometry, and nuclear magnetic resonance data ((1)H and (1)H COSY NMR) . Toxin 1 was identified as MCYST-LR, and toxin 2, a new MCYST, as MCYST-LHArg ({L-homoarginine(4)}) . Previous studies indicate that Oscillatoria agardhii strains produce demethylated MCYSTs (containing D-Asp and/or dehydroalanine) . This is the first report of a toxic O . tenuis, strain E6, one which produces a fully methylated MCYST, MCYST-LR and a new L-homoarginine containing MCYST, MCYST-LHArg. Sci Total Environ, 2000 May 24, 254(1), 55 - 64 Calculation and mapping of critical loads of sulfur and nitrogen in Flanders, Belgium; Craenen H et al.; Up to now, critical loads calculations for the Flemish Region were based on European background data of surrounding countries . A first attempt has been made to calculate and map critical loads for forest ecosystems in Flanders using available site-specific information . Values of current deposition were used to calculate and map exceedances . The lowest critical loads for acidification (697 eq ha(-1)year(-1)) occur in the Campine and the north of Limburg where ecosystems largely consist of coniferous forests on poor sandy soils . The dominance of coniferous forest types in the Campine is also responsible for low critical load values for eutrophication (between 536 and 971 eq ha(-1)year(-1)) . In 75% of the receptor points that have been considered an exceedance of the critical load for acidification is noted, primarily in areas with high SO2 and NOx depositions, such as the north of the provinces East and West Flanders and Antwerp . The critical load for eutrophication is exceeded in all points considered . Exceedances are particularly high in coniferous forests in West Flanders, and in the north of the provinces of Antwerp and Limburg, where especially NHx depositions amount to high values . Data needed for the calculation of critical loads are still sparse in Flanders, e.g . for: (1) weathering rates of soil minerals; (2) interception and evaporation of forest ecosystems; and (3) uptake of N and basic cations by vegetation . This supplementary information will contribute to a further refining of the calculated critical loads, which constitute indispensable information in developing an emission abatement policy. Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 43 - 6 Health impairments arising from drinking water polluted with domestic sewage and excreta in China; Ling B; Raw water of poor quality still causes many drinking-water associated health problems all over China, largely because of poor sanitation, inadequate disposal of sewage and excreta . Eutrophication due to excess of total nitrogen and phosphorous in some sources for drinking-water has led to massive proliferation of cyanobacteria . The dominant species of cyanophyta can produce microcystins, a potent liver cancer promotor . As in previous studies, high incidence of liver cancer coincided with high microcystin concentration in the source water, especially in pond water . A frequent consequence of heavy pollution of source water is further the high incidence of infectious intestinal diseases, which are more than 10-100 times as frequent in China than in developed countries. Parasitol Res, 2000 May, 86(5), 359 - 72 Parasite communities of the Salzhaff (Northwest Mecklenburg, Baltic Sea) II . Guild communities, with special regard to snails, benthic crustaceans, and small-sized fish; Zander CD et al.; Metazoan parasites of guilds of benthic snails and crustaceans and of four fish families--Gobiidae, Gasterosteidae, Syngnathidae, and Zoarcidae--were investigated off the brackish Salzhaff area (Southwest Baltic) in the semienclosed Salzhaff and the near Rerik Riff in the free Baltic . Comparisons revealed greater similarities in parasite populations and communities within the fish guilds than between them . According to an evaluation of the core-/satellite-species concept using abundance values, the most important parasites of fish were some generalists, such as Cryptocotyle spp., Podocotyle atomon, and Diplostomum spathaceum, as well as some specialists, such as Acanthostomum balthicum, Thersitina gasterostei, and Aphalloides timmi . These specialists revealed high degrees of prevalence in their main hosts and lower degrees in one or two by-hosts . Additional importance is assigned to parasites that cause harm to their hosts due to their large size, e.g., Schistocephalus spp., or via massive infestation, e.g., several digenean metacercariae . Because specialists were more prominent in snails and fish from the Rerik Riff, the correlation of host numbers with prevalence resulted in only a slight increase instead of a more rapid rise in regression among crustaceans and fish from the entire Salzhaff, where the generalists were more prevalent . The selected host guilds demonstrated the entire life cycles of three digeneans (P . atomon, A . balthicum, A . timmi), one acanthocephalan (Echinorhynchus gadi), and one nematode (Hysterothylacium sp.) . The prevalence increased in these cycles from host level to host level and attained relatively high values in all guilds . The parasite fauna of the Salzhaff area is influenced by eutrophication stress, which leads to a high level of productivity and, consequently, to great densities in primary consumers such as snails and crustaceans . These are attractive for several secondary consumers such as fish and birds, which is the reason for the existence of at least 24 autogenic and 20 allogenic parasite species at this locality . The slight surplus of the first category indicates a yet-balanced environment in the investigation area. Nature, 2000 May 18, 405(6784), 340 - 4 Functional diversity governs ecosystem response to nutrient enrichment; Hulot FD et al.; The relationship between species diversity and ecosystem functioning is a central topic in ecology today . Classical approaches to studying ecosystem responses to nutrient enrichment have considered linear food chains . To what extent ecosystem structure, that is, the network of species interactions, affects such responses is currently unknown . This severely limits our ability to predict which species or functional groups will benefit or suffer from nutrient enrichment and to understand the underlying mechanisms . Here our approach takes ecosystem complexity into account by considering functional diversity at each trophic level . We conducted a mesocosm experiment to test the effects of nutrient enrichment in a lake ecosystem . We developed a model of intermediate complexity, which separates trophic levels into functional groups according to size and diet . This model successfully predicted the experimental results, whereas linear food-chain models did not . Our model shows the importance of functional diversity and indirect interactions in the response of ecosystems to perturbations, and indicates that new approaches are needed for the management of freshwater ecosystems subject to eutrophication. Chemosphere, 2000 Jul, 41(1-2), 53 - 8 Use of protein phosphatase inhibition assay to detect microcystins in Donghu Lake and a fish pond in China; Xu LH et al.; Seasonal variations in the level of total microcystins in water samples collected from Donghu Lake and a fish pond in Wuhan, China, were studied between March 1995 and February 1996 using a protein phosphatase inhibition assay involving a radioactive 32P-labelled substrate . The assay is highly reliable and repeatable, and is probably the most sensitive assay for microcystin detection to date . Results of the survey indicated the presence of microcystins in the water samples, and the concentration of microcystins appeared to be related to the degree of eutrophication and water temperature . There is also a correlative relationship between the quantity of microcystins and the abundance of microcystin-producing cyanobacteria (Anabaena and Oscillatoria) in the water bodies over a year cycle . In the present study, the positive detection of microcystins in water bodies having no signs of algal bloom warns of considerable potential threat of these waters to public health. Sci Total Environ, 2000 Mar 29, 248(1), 63 - 70 The use of epiphyton and epilithon data as a base for calculating ecological indices in monitoring of eutrophication in lakes in central Sweden; Danilov RA et al.; Eutrophication was monitored with the aid of one similarity and seven diversity indices in the lakes of different trophic levels (eutrophic, mesotrophic and oligotrophic) in central Sweden . The ecological indices were applied separately to epiphyton and epilithon communities . Epiphyton turned out to be inappropriate for assessing eutrophication in the lakes studied . On the other hand, Hurlbert's, Simpson's and the similarity indices turned out to be promising environmental tools when applied to the data of epilithon. Sci Total Environ, 2000 Apr 5, 248(2-3), 87 - 99 Atmospheric nitrogen in the Mississippi River Basin--emissions, deposition and transport; Lawrence GB et al.; Atmospheric deposition of nitrogen has been cited as a major factor in the nitrogen saturation of forests in the north-eastern United States and as a contributor to the eutrophication of coastal waters, including the Gulf of Mexico near the mouth of the Mississippi River . Sources of nitrogen emissions and the resulting spatial patterns of nitrogen deposition within the Mississippi River Basin, however, have not been fully documented . An assessment of atmospheric nitrogen in the Mississippi River Basin was therefore conducted in 1998-1999 to: (1) evaluate the forms in which nitrogen is deposited from the atmosphere; (2) quantify the spatial distribution of atmospheric nitrogen deposition throughout the basin; and (3) relate locations of emission sources to spatial deposition patterns to evaluate atmospheric transport . Deposition data collected through the NADP/NTN (National Atmospheric Deposition Program/National Trends Network) and CASTNet (Clean Air Status and Trends Network) were used for this analysis . NOx Tier 1 emission data by county was obtained for 1992 from the US Environmental Protection Agency (Emissions Trends Viewer CD, 1985-1995, version 1.0, September 1996) and NH3 emissions data was derived from the 1992 Census of Agriculture (US Department of Commerce . Census of Agriculture, US Summary and County Level Data, US Department of Commerce, Bureau of the Census . Geographic Area series, 1995:1b) or the National Agricultural Statistics Service (US Department of Agriculture . National Agricultural Statistics Service Historical Data . Accessed 7/98 at URL, 1998 . +.htm) . The highest rates of wet deposition of NO3- were in the north-eastern part of the basin, downwind of electric utility plants and urban areas, whereas the highest rates of wet deposition of NH4+ were in Iowa, near the center of intensive agricultural activities in the Midwest . The lowest rates of atmospheric nitrogen deposition were on the western (windward) side of the basin, which suggests that most of the nitrogen deposited within the basin is derived from internal sources . Atmospheric transport eastward across the basin boundary is greater for NO3- than NH4+, but a significant amount of NH4+ is likely to be transported out of the basin through the formation of (NH4)2SO4 and NH4NO3 particles--a process that greatly increases the atmospheric residence time of NH4+ . This process is also a likely factor in the atmospheric transport of nitrogen from the Midwest to upland forest regions in the North-East, such as the western Adirondack region of New York, where NH4+ constitutes 38% of the total wet deposition of N. Obes Surg, 1992 Aug, 2(3), 263 - 264 Eutrophication: spontaneous progressive dermatoliponecrosis . A Fatal Complication of Gross Morbid Obesity; Ramsey-Stewart G; Spontaneous and progressive dermatoliponecrosis and panniculitis is an unusual complication of morbid obesity . A fatal case is reported, and the term eutrophication is suggested as an appropriately descriptive name for this intractable condition . A 45-year-old grossly morbidly obese female (weighing 286.4 kg) presented with spontaneous necrosis of skin and fat-folds of the abdomen, trunk, and thighs . She also had congestive cardiac failure, respiratory insufficiency and anemia . Congestive cardiac failure and anemia were treated aggressively . However, all attempts at control of the superficial tissue necrosis and the supervening infection failed . Superficial gangrene and putrefaction of the fat-folds progressed relentlessly, and death finally ensued due to sepsis and multiple system failure . The early signs of panniculitis, especially of grossly dependent fat and skin-folds in the morbidly obese must be recognized early and treated with aggressive weight loss, if this potentially fatal complication of morbid obesity is to be avoided. J, Exp . Mar . Biol . Ecol. . 2000 May 18, 248(1), 79 - 104 Drifting algal mats as an alternative habitat for benthic invertebrates: Species specific responses to a transient resource; Norkko J et al.; Patchy occurrences of benthic drift algae (i.e . loose lying macroalgal mats) may increase habitat complexity on normally bare soft bottoms, but at the same time, extensive amounts of drifting algal mats are known to stress the benthic fauna . This paper presents results of the first detailed study of the fauna associated with drift algal mats in the northern Baltic Sea . In order to assess the importance of drifting algae as an alternative habitat for benthic fauna, benthic drift algal mats were sampled on shallow (2-9 m) sandy soft bottoms in the outer archipelago of the Aland Islands (Finland) . Species composition, abundance and biomass of the macrofauna associated with algal mats were recorded . The results show that drifting algae at times can harbour very high abundances of invertebrates (up to 1116 individuals/g algal dryweight), surpassing invertebrate densities recorded in seagrass communities . The algal fauna varied between sites and over time, and factors such as ambient benthic fauna, exposure to wind-wave disturbance, depth, and algal coverage and condition influenced the invertebrate community composition of the algal mats . Abundance increased while individual biomass of the animals decreased over time (summer season; July-October) . A series of laboratory experiments were conducted in order to test the ability of a few important benthic species to move up into, and survive in a drifting algal mat . Macoma balthica, Hydrobia spp., Nereis diversicolor and Bathyporeia pilosa were used in the experiments, and significant differences in their survival and mobility within drifting algae were recorded . This study shows that benthic species differ significantly in their ability to utilise the algal mats, with mainly opportunistic and mobile taxa such as Hydrobia spp., Chironomidae and Ostracoda benefiting from the algae, whereas infaunal species such as M . balthica and B . pilosa are negatively affected . The occurrence of eutrophication induced drifting macroalgal mats has increased significantly during the last decade in the northern Baltic Sea . Hence, the importance of drifting algae as a stress factor and as an alternative habitat for benthic fauna increases. C R Acad Sci III, 2000 Feb, 323(2), 225 - 33 {Seasonal evolution of the biogeochemical cycle in the southwest lagoon of New Caledonia . Application of a compartmental model}; Bujan S et al.; A biogeochemical box model describing the south-west lagoon of New-Caledonia was developed in order to simulate the seasonal cycle of carbon and nitrogen . We used fluxes generated by a 3D hydrodynamic model to simulate horizontal exchanges between boxes and added freshwater influxes as nitrogen sources from the land . Average residence time proved to be less than 11 days for the lagoon as a whole . Standard simulations showed baseline values of chlorophyll a between 0.2 and 0.4 microgram.L-1 . Influences of freshwater influxes proved to be significant (increases up to 1 microgram.L-1) only in shallow areas protected from wind exposure and during short periods of heavy rainfall (tropical depressions) . Tropical climatic events have reduced impact in space and time and long-term simulations over decades with increased nutrient inputs did not show any significant process of eutrophication . Hydrodynamics seemed to be one of the major control factors with respect to organic matter cycling in the lagoon. Poult Sci, 2000 Feb, 79(2), 172 - 9 Nutrient flows for poultry production in The Netherlands; De Boer IJ et al.; Government targets for ammonia emission and for N and P loss per hectare (ha) of agricultural land were used to assess carrying capacity for poultry production in The Netherlands with data from 1990 . In addition, the effect of alternative management strategies on carrying capacity was determined . Ammonia emission from poultry production in 1990 {20.5 gigagrams (Gg) N} exceeded the target for 2000 (i.e., 6.9 Gg N) . Targets defined for 2000 and 2010 (i.e., 4.6 Gg N) can be achieved, however, without reducing poultry numbers, assuming national introduction of measurements studied . Measures that reduced ammonia emission directly, i.e., introduction of low-emission housing or manure application techniques, were most effective . In 1990, N and P losses equalled 215 kg/ha for N and 31 kg/ha for P . The N loss was slightly lower than the target for 2000 (219 kg N/ha) but exceeded the target for 2010 (144 kg N/ha) . Reduction of application of artificial N fertilizer, however, reduced N loss effectively from 215 to 22 kg/ha . National P loss in 1990 exceeded the target for 2000 (15.3 kg P/ha) . Reduction of application of artificial P fertilizer reduced P loss most effectively from 31 to 14 kg/ha . To achieve the target for 2010 (8.7 kg P/ha), additional reduction in P excretion by poultry is required . This reduction can be achieved by use of phytase in layer and broiler feed and by use of a coarse Ca source in layer feed . Unlike pig production, carrying capacity for poultry production in The Netherlands is not limited by governmental targets for acidification, eutrophication, or drinking water contamination. Environ Health Perspect, 2000 Mar, 108(3), A120 - 5 The dead zones: oxygen-starved coastal waters; Joyce S; After the great Mississippi River flood of 1993, the hypoxic (or low-oxygen) "dead zone" in the Gulf of Mexico more than doubled its size, reaching an all-time high of over 7,700 square miles in July of 1999 . Scientists attribute the Gulf of Mexico dead zone largely to nutrient runoff from agriculture in the Mississippi River basin . During the warm months, these nutrients fuel eutrophication, or high organic production, causing large algal blooms . When the algae decay, the result is hypoxia . Reports of such hypoxic events around the world have been increasing since the mid 1960s . Eutrophication and hypoxia have resulted in mortality of bottom-dwelling life in dozens of marine ecosystems and have stressed fisheries worldwide . Some algal blooms can alter the function of coastal ecosystems or, potentially, threaten human health . Anthropogenic nutrient loading from sources such as agriculture, fossil fuel emissions, and climate events is believed to be related to the global increase in frequency, size, and duration of certain algal blooms. Nature, 2000 Feb 17, 403(6771), 758 - 61 Effect of stream channel size on the delivery of nitrogen to the Gulf of Mexico Alexander RB, Smith RA, Schwarz GE. An increase in the flux of nitrogen from the Mississippi river during the latter half of the twentieth century has caused eutrophication and chronic seasonal hypoxia in the shallow waters of the Louisiana shelf in the northern Gulf of Mexico . This has led to reductions in species diversity, mortality of benthic communities and stress in fishery resources . There is evidence for a predominantly anthropogenic origin of the increased nitrogen flux, but the location of the most significant sources in the Mississippi basin responsible for the delivery of nitrogen to the Gulf of Mexico have not been clearly identified, because the parameters influencing nitrogen-loss rates in rivers are not well known . Here we present an analysis of data from 374 US monitor ing stations, including 123 along the six largest tributaries to the Mississippi, that shows a rapid decline in the average first-order rate of nitrogen loss with channel size--from 0.45 day (-1) in small streams to 0.005 day (-1) in the Mississippi river . Using stream depth as an explanatory variable, our estimates of nitrogen-loss rates agreed with values from earlier studies . We conclude that the proximity of sources to large streams and rivers is an important determinant of nitrogen delivery to the estuary in the Mississippi basin, and possibly also in other large river basins. An Acad Bras Cienc, 1999, 71(4 Pt 2), 1017 - 35 Recent trends in environmental and ecological modelling; Jorgensen SE; The paper outlines the history of modelling and presents a status of ecological modelling: what is the modelling effort of various ecosystem and various environmental problems . Typical validation results and prognosis validation results of a eutrophication model are applied as an illustration of what models can do in environmental management . Structural dynamic modelling which considers parameters that are changed currently by optimisation of a so-called goal function is presented as one of the recent development to overcome one of the most crucial problems in modelling, namely to consider adaptation . Two case studies are presented to illustrate this approach, namely application of biomanipulation and eutrophication of a shallow lake . Forecast on the directions of development is finally presented. Sci Total Environ, 1999 Dec 15, 243-244, 43 - 52 Estimates of early-industrial inputs of nutrients to river systems: implication for coastal eutrophication; Billen G et al.; Although coastal eutrophication is generally recognised as a recent phenomenon related to the well-documented increase in riverine nutrient delivery during the last 30 or 40 years, a few historical records paradoxically show that, in some places like the Southern Bight of the North Sea, or the Northern Adriatic, algal proliferation as intense as presently observed was already regularly occurring at the end of the 19th century . Estimated riverine nutrient loads from diffuse sources or from domestic point sources of waste water at that time are too low to account for these observations . We attempted a retrospective evaluation of the possible contribution of industrial activity to nutrient river loading . The figures indicate that, by the end of the last century, large scale use of traditional processes in textile and paper industries, in tanneries, candles factories and others was responsible for a dominant part of the nutrient load carried by rivers in Western Europe and could have caused nutrient inputs to coastal zones similar to the present ones. Science, 1999 Dec 24, 286(5449), 2485 - 8 Oligotrophy and nitrogen fixation during eastern mediterranean sapropel events Sachs JP, Repeta DJ. Nitrogen isotopic measurements in fossil chlorophyll from late Pleistocene organic-rich sediments (sapropels) in the eastern Mediterranean Sea provide geochemical evidence for stratified, nutrient-depleted surface water and extensive nitrogen fixation . This evidence is reconciled with previous indications of high productivity by invoking a model of sapropel formation in which increased river discharge facilitates development of a specialized phytoplankton population whose annual mass sinking provides the organic flux to generate sapropels . This interpretation is consistent with the widespread occurrence of mat-forming diatoms that thrive in stratified water and can harbor diazotrophic bacterial symbionts, but does not support eutrophication of surface waters by enhanced river runoff or a circulation reversal. Microb Ecol, 1999 Oct, 38(3), 264 - 272 Differential Dissolved Organic Nitrogen Availability and Bacterial Aminopeptidase Activity in Limnic and Marine Waters; Stepanauskas R et al.; Abstract Nitrogen often limits primary production in marine ecosystems and its loading from terrestrial sources is the major cause of enhanced coastal eutrophication worldwide . About 70% of nitrogen transported by rivers globally is dissolved organic nitrogen (DON) . Therefore, terrestrial DON is potentially an important component of the N dynamics in aquatic ecosystems, but the bioavailability of this organic nitrogen is poorly known . Bacterial extracellular hydrolysis of polymers is a bottleneck in the utilization of natural dissolved organic matter, mostly consisting of high molecular weight compounds . To study the bacterial utilization and extracellular enzymatic hydrolysis of DON, we developed a bioassay employing natural DON as the only N source, and N as the limiting nutrient . Bacterial cell density and activity of an unspecific aminopeptidase (AMPase) were followed in the cultures . Natural DON stimulated the cell-specific AMPase activity . Furthermore, refractory and humus-rich DOM caused a stronger stimulation than labile DOM . We propose that the previously reported inhibitory effect of humic substances on enzyme activity was outweighed by the induction of enzyme synthesis caused by refractory substrates . AMPase activity and the estimated DON bioavailability were more than twofold higher in seawater than in freshwater with identical substrate additions . This indicates that hydrolysis and turnover of land-derived DON is enhanced when it enters coastal marine waters, enabling it to support elevated bacterioplankton and phytoplankton growth.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p264.html</hea Sci Total Environ, 1999 Sep 15, 236(1-3), 19 - 39 The fate of metals in Arctic surface waters . Method for defining critical levels; Moiseenko TI; Based upon studies in the industrially developed Arctic region, Russian Kola, here we discuss the fate of metals in high latitude surface water . Mainly, attention is paid to the priority pollutants from copper-nickel smelters . The influence of accompanying processes, such as acidification and eutrophication, on metal behavior is considered . The dramatic situation for fauna of Arctic latitudes is illustrated: (i) during the snow-melt, due to the pulse of ionic metal forms; and (ii) during the long polar winter in lower water layers, due to the involvement of a wide spectrum of metals in the redox-cycle under eutrophication and oxygen deficiency . Here we identify fish pathologies, which are related to the influence of metals . Generalizing the data on metal behavior, an original approach to define the integrated impact dose of metals--a toxicity index--has been developed . It presents a visualization of the integrated toxicity index for surface waters of the Russian Kola (based on the data for a 460-lake survey) . As shown, there is a risk of fish diseases, due to both airborne contamination by metals and an indirect leaching by acid runoff over almost 30% of the area of the Russian Kola . For the Arctic region, polar winter stress syndrome will be repeatedly significant . During the polar night, as well as the spring, the vulnerability of the Arctic biota to toxic impact is higher . The accompaniment of water metal-pollution by two or more stressors would occur simultaneously, thereby multiplying the risk that it could develop. FEMS Microbiol Rev, 1999 Oct, 23(5), 563 - 90 Nitrogen cycling in coastal marine ecosystems; Herbert RA; It is generally considered that nitrogen availability is one of the major factors regulating primary production in temperate coastal marine environments . Coastal regions often receive large anthropogenic inputs of nitrogen that cause eutrophication . The impact of these nitrogen additions has a profound effect in estuaries and coastal lagoons where water exchange is limited . Such increased nutrient loading promotes the growth of phytoplankton and fast growing pelagic macroalgae while rooted plants (sea-grasses) and benthic are suppressed due to reduced light availability . This shift from benthic to pelagic primary production introduces large diurnal variations in oxygen concentrations in the water column . In addition oxygen consumption in the surface sediments increases due to the deposition of readily degradable biomass . In this review the physico-chemical and biological factors regulating nitrogen cycling in coastal marine ecosystems are considered in relation to developing effective management programmes to rehabilitate seagrass communities in lagoons currently dominated by pelagic macroalgae and/or cyanobacteria. Am Nat, 1999 Oct, 154(4), 449 - 468 Patterns in the Fate of Production in Plant Communities; Cebrian J; I examine, through an extensive compilation of published reports, the nature and variability of carbon flow (i.e., primary production, herbivory, detrital production, decomposition, export, and biomass and detrital storage) in a range of aquatic and terrestrial plant communities . Communities composed of more nutritional plants (i.e., higher nutrient concentrations) lose higher percentages of production to herbivores, channel lower percentages as detritus, experience faster decomposition rates, and, as a result, store smaller carbon pools . These results suggest plant palatability as a main limiting factor of consumer metabolical and feeding rates across communities . Hence, across communities, plant nutritional quality may be regarded as a descriptor of the importance of herbivore control on plant biomass ("top-down" control), the rapidity of nutrient and energy recycling, and the magnitude of carbon storage . These results contribute to an understanding of how much and why the trophic routes of carbon flow, and their ecological implications, vary across plant communities . They also offer a basis to predict the effects of widespread enhancement of plant nutritional quality due to large-scale anthropogenic eutrophication on carbon balances in ecosystems. Nat Toxins, 1999, 7(2), 81 - 4 Possible cause of unnatural mass death of wild birds in a pond in Nishinomiya, Japan: sudden appearance of toxic cyanobacteria; Matsunaga H et al.; During the summer of 1995, about 20 spot-billed ducks died unnaturally in a pond (Shin-ike) in Nishinomiya, Hyogo Prefecture, Japan . The suspected cause was the sudden appearance of toxic freshwater bloom of cyanobacteria . However, no birds died in a nearby pond (Oo-ike) in which the cyanobacteria was also present . Morphological observation of these cyanobacteria by microscope revealed that they were almost unialgal and were both Microcystis aeruginosa . The lyophilized algal cell powder from Shin-ike contained large amounts of microcystins which showed acute toxicity for mouse, while that from Oo-ike had only a very small amount of microcystin-RR which did not show acute toxicity . Autopsy of one of the birds revealed that the liver was necrotic and severely jaundiced with a dark green color, suggesting the toxicity of the microcystins . These results point to the cause of the unnatural death of spot-billed ducks in Shin-ike as being the sudden appearance of toxic Microcystis aeruginosa . This was due to eutrophication of the pond, following the influx of untreated sewage related to damage from the Great Hanshinn Earthquake of January 1995 . This is the first experimental report of toxic cyanobacteria being implicated in the mass death of wild birds in Japan . Sci Total Environ, 1999 Jun 15, 231(1), 17 - 35 Eutrophication process recorded in dinoflagellate cyst assemblages--a case of Yokohama Port, Tokyo Bay, Japan; Matsuoka K; To investigate temporal changes of water quality, a role of dinoflagellate cysts preserved in surface sediments was examined in Yokohama Port in Tokyo Bay, Japan . Two cores were collected, and sedimentation rates and ages of both were dated as approximately 1900 years or slightly older on the basis of 210Pb and 137Cs concentrations . The temporal change in dinoflagellate cyst assemblages in the two cores reflects eutrophication in Yokohama Port in the 1960s . Abrupt increases in the cysts of Gyrodinium instriatum cysts strongly suggests that a red tide was caused by this species around 1985 . Dinoflagellate cyst assemblages in surface sediments appear to be good biomarkers of changes in the water quality of enclosed seas. Science, 1999 Aug 27, 285(5432), 1396 - 1398 Eutrophication, Fisheries, and Consumer-Resource Dynamics in Marine Pelagic Ecosystems; Micheli F; Anthropogenic nutrient enrichment and fishing influence marine ecosystems worldwide by altering resource availability and food-web structure . Meta-analyses of 47 marine mesocosm experiments manipulating nutrients and consumers, and of time series data of nutrients, plankton, and fishes from 20 natural marine systems, revealed that nutrients generally enhance phytoplankton biomass and carnivores depress herbivore biomass . However, resource and consumer effects attenuate through marine pelagic food webs, resulting in a weak coupling between phytoplankton and herbivores . Despite substantial physical and biological variability in marine pelagic ecosystems, alterations of resource availability and consumers result in general patterns of community change. Parasitol Res, 1999 Aug, 85(8-9), 726 - 32 Occurrence of trichodinid ciliates (Peritricha : Urceolariidae) in the Kiel Fjord, Baltic Sea, and its possible use as a biological indicator; Palm HW et al.; Investigations on the occurrence of trichodinid ciliates from fish caught in the Kiel Bight and Kiel Fjord (western Baltic Sea) were carried out between September 1996 and March 1997 . Smears of the gills, fins, and skin of 120 Gadus morhua and 92 Platichthys flesus caught by fish traps and trammel nets revealed the presence of trichodinid ciliates . According to the fish species and locality, different prevalences and densities of trichodinid ciliates were found . Fish caught in the Kiel Bight revealed a lower prevalence of trichodinid ciliates on their gills (P . flesus 74.2%, G . morhua 3.8%) in comparison with fish of the same species and size caught in the Kiel Fjord (P . flesus 75.0%, G . morhua 26.2%) . In both areas, P . flesus was more heavily infested than G . morhua . Seasonal changes in the prevalence of infestation of P . flesus between autumn and winter in the Kiel Fjord are proposed to be linked to an increase in bacterial biomass during winter . The fish ecology in combination with the total number of bacteria in the fish environment is discussed as an important factor influencing the abundance of trichodinid ciliates . The present data suggest the use of trichodinid ciliates as an indicator for eutrophication in brackish-water environments. Regul Toxicol Pharmacol, 1999 Jun, 29(3), 309 - 18 Evaluation of the EPA exposure assessment for phosphoric acid; Morley KM; The philosophy of this paper is that the Environmental Protection Agency's (EPA) 1990 exposure assessment for phosphoric acid is not based on sound science and therefore does not accurately characterize the eutrophication potential of phosphoric acid releases from Toxic Release Inventory (TRI) reporting facilities . This error propagates the myth that eutrophication is triggered by the release of phosphoric acid from facilities reporting releases in the TRI . A detailed evaluation of EPA's 1990 exposure assessment for phosphoric acid reveals critical flaws in their applied methodology . Significant methodological improvements detailed in this paper fundamentally alter EPA's 1990 exposure assessment and demonstrate that, contrary to EPA's conclusion, these sources of phosphoric acid do not have the potential to trigger eutrophication in surface waters . Therefore, when sound scientific principles are applied in this comparative exposure assessment, EPA's policy maintaining phosphoric acid on the TRI list is inappropriate . Proc Natl Acad Sci U S A, 1999 May 25, 96(11), 5995 - 6000 Global environmental impacts of agricultural expansion: the need for sustainable and efficient practices; Tilman D; The recent intensification of agriculture, and the prospects of future intensification, will have major detrimental impacts on the nonagricultural terrestrial and aquatic ecosystems of the world . The doubling of agricultural food production during the past 35 years was associated with a 6.87-fold increase in nitrogen fertilization, a 3.48-fold increase in phosphorus fertilization, a 1.68-fold increase in the amount of irrigated cropland, and a 1.1-fold increase in land in cultivation . Based on a simple linear extension of past trends, the anticipated next doubling of global food production would be associated with approximately 3-fold increases in nitrogen and phosphorus fertilization rates, a doubling of the irrigated land area, and an 18% increase in cropland . These projected changes would have dramatic impacts on the diversity, composition, and functioning of the remaining natural ecosystems of the world, and on their ability to provide society with a variety of essential ecosystem services . The largest impacts would be on freshwater and marine ecosystems, which would be greatly eutrophied by high rates of nitrogen and phosphorus release from agricultural fields . Aquatic nutrient eutrophication can lead to loss of biodiversity, outbreaks of nuisance species, shifts in the structure of food chains, and impairment of fisheries . Because of aerial redistribution of various forms of nitrogen, agricultural intensification also would eutrophy many natural terrestrial ecosystems and contribute to atmospheric accumulation of greenhouse gases . These detrimental environmental impacts of agriculture can be minimized only if there is much more efficient use and recycling of nitrogen and phosphorus in agroecosystems. Trends Ecol Evol, 1999 Feb, 14(2), 63 - 68 Constraints in the restoration of ecological diversity in grassland and heathland communities; Bakker JP et al.; Species-rich grassland and heathland communities still occur in low-intensity farming systems in many European countries . Gradually, such systems have either been abandoned or more intensively exploited, with a subsequent decrease in species numbers . Until recently, it was thought that restoration of these communities would be straightforward . However, abiotic constraints (with respect to eutrophication and acidification) have hampered restoration more than previously thought . Moreover, very recent research has revealed that biotic constraints can also be important: many plant species are not present in the soil seed bank and their dispersal is limited in the present fragmented landscape. Lipids, 1999 Mar, 34(3), 291 - 7 Fatty acid composition of 19 species of fish from the Black Sea and the Marmara Sea; Tanakol R et al.; Evidence suggests that differences in fatty acid composition among various fish species may be due to differences in diet or to environmental factors such as temperature, salinity, and depth at which the fish are caught . The beneficial effects of a diet containing fish on cardiovascular or other diseases have been associated with their high content of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids . In this study we analyzed the fatty acid composition of the flesh of 18 different species of marine fish and of cultured rainbow trout . The fish were obtained from the Black and the Marmara Seas, both of which have unique biological and ecological systems as well as eutrophication and pollution . The contents of 20:5n-3 and 22:6n-3 in the marine fish ranged from 4.2 to 13.3 wt% of total fatty acids, and from 6.6 to 40.8 wt%, respectively . The most important differences from other studies on oceanic fish were the tendencies toward higher percentages of 16:0 and 22:6n-3 . The n-3 series of polyunsaturated fatty acids were present as 32.4+/-1.9% of the total fatty acids . The present study suggests that mature and immature Pomatomus saltator as well as Engraulis encrasicolus, Mullus surmuletus, Sardina pilchardus, Mugil cephalus, and Sarda sarda may be preferred for the Turkish diet as a result of their high 20:5n-3 and 22:6n-3 contents . The cultured rainbow trout Oncorhynchus mykiss is not as good a source of n-3 fatty acids as are the marine fish. Poult Sci, 1999 May, 78(5), 674 - 82 Phosphorus: a rate limiting nutrient in surface waters; Correll DL; Phosphorus is an essential element for all life forms . It is a mineral nutrient . Orthophosphate is the only form of P that autotrophs can assimilate . Extracellular enzymes hydrolyze organic forms of P to phosphate . Eutrophication is the over-enrichment of surface waters with mineral nutrients . The results are excessive production of autotrophs, especially algae and cyanobacteria . This high productivity leads to high bacterial populations and high respiration rates, leading to hypoxia or anoxia in poorly mixed bottom waters and at night in surface waters during calm, warm conditions . Low dissolved oxygen causes the loss of aquatic animals and the release of many materials normally bound to bottom sediments, including various forms of P . This release of P reinforces the eutrophication . Excessive concentrations of P is the most common cause of eutrophication in freshwater lakes, reservoirs, streams, and in the headwaters of estuarine systems . In the ocean, N is believed to usually be the key mineral nutrient controlling primary production . Estuaries and continental shelf waters are a transition zone, in which excessive P and N create problems . It is best to measure and regulate total P inputs to whole aquatic ecosystems, but for an easy assay it is best to measure total P concentrations, including particulate P, in surface waters or N:P atomic ratios in phytoplankton. Poult Sci, 1999 May, 78(5), 660 - 73 Agricultural phosphorus, water quality, and poultry production: are they compatible? Sharpley A. With the concentration of poultry production and increase in operation size in several regions of the U.S., more manure is applied to agricultural land . This application of manure has resulted in more P being added than crops require, an accumulation in soil P, and increased potential for P loss in surface runoff . This situation has been exacerbated by manure management being N-based . Increased outputs of P to fresh waters can accelerate eutrophication, which impairs water use and can lead to fish kills and toxic algal blooms . As a result, information is needed on the effect of poultry production on the fate of P in agricultural systems so that compatible production and water quality goals can be met . Overall, these goals will be met by focusing on ways to increase P use-efficiency by attempting to balance inputs of P in feed and fertilizer into a watershed with output in crop and livestock . This will involve refining feed rations, using feed additives to increase P absorption by the animal, moving manure from surplus to deficit areas, finding alternative uses for manure, and targeting conservation practices, such as reduced tillage, buffer strips, and cover crops, to critical areas of P export from a watershed . These critical areas are where high P soils coincide with parts of the landscape where surface runoff and erosion potential is high . Development of management systems that address both production and environmental concerns must consider the socioeconomic and political impacts of any management changes on both rural and urban communities, and of the mechanisms by which change can be achieved in a diverse and dispersed community of land users. Toxicon, 1998 Dec, 36(12), 1895 - 901 Photocatalytic degradation of cyanobacterial microcystin toxins in water; Shephard GS et al.; The microcystins are hepatotoxins produced by a number of cyanobacterial species (blue green algae) in fresh water systems . The increasing eutrophication of natural waters has led to an increase in the incidence of algal blooms and the consequent increased risk of microcystin contamination of water resources . The removal of microcystins LR, YR and YA from contaminated water was investigated using an experimental laboratory-scale photocatalytic 'falling film' reactor in which an oxygen purge, UV radiation and semiconductor titanium dioxide (TiO2) catalyst were used to oxidatively decompose the microcystin pollutants . Preliminary studies, using algal extracts spiked into distilled water, indicated that the microcystins were rapidly decomposed in this reactor . The decomposition followed first order reaction kinetics with half-lives of less than 5 min with the reactor operating in a closed-loop mode . Reaction rates were strongly dependent on the amount of TiO2 catalyst (O-5 g/l), but only marginally influenced by a change in gas purge from oxygen to compressed air . The use of lake water, rather than distilled water, showed that this process is feasible in natural waters, although increased levels of catalyst (up to 5 g/l) were required to achieve comparable decomposition rates. Parassitologia, 1997 Sep, 39(3), 233 - 6 Eutrophication, pollution and fragmentation: effects on the parasite communities in roach and perch in four lakes in central Finland; Valtonen ET et al.; Parasite communities in the four study lakes reflected the influences of habitat fragmentation, pollution and eutrophication . Discriminant analysis of communities at the individual host level reveal two major axes . One, characterized by reduced numbers of digeneans and myxosporeans and increased numbers of acanthocephalans and monogeneans, contrasts communities in a lake affected by chemical pollution from a pulp mill with two eutrophic, less polluted lakes . Changes in the density of intermediate hosts, direct effects on ectoparasites and impaired immune systems were regarded as important mechanisms . The second contrasts communities in an oligotrophic, unpolluted lake with the two eutrophic lakes, and was more complex, reflecting habitat fragmentation, and pollution or eutrophication, probably mediated by the same mechanisms as above . Monitoring easily seen discriminating parasites following 8 years of reduced pollutant loading showed some, but not all, of the effects of pollution could be reserved in a relatively short time. Naturwissenschaften, 1998 Sep, 85(9), 426 - 36 Ecology of host parasite relationships in the Baltic Sea; Zander CD; The Baltic Sea is one of the greatest brackish waters, and for 7000 years it has been affected by the influx of haline waters from the North Sea . Many marine and some fresh water organisms have adapted to its lower salinity . Some organisms, referred to as genuine brackish water species, predominate over their near relatives in this environment . All these elements are also present among parasites, which differ in the degree of specialization to their hosts . Analyses of parasite communities, especially those of small fish hosts, reveal characteristics which differ from communities in the marine milieu: (a) suspension of specificity, (b) new hosts, (c) reduction in the number of hosts in life cycles, and (d) adaptation to genuine brackish water hosts . The view of the Baltic Sea as a species-poor but balanced ecosystem is also valid for parasites . The Baltic Sea is endangered by the high level of eutrophication, as the organisms are not adapted to its consequences . The study of parasite communities reveals such threatening conditions for the respective environments. Sci Total Environ, 1998 Jul 11, 218(1), 67 - 83 Bioaccumulation of radionuclides in fertilized Canadian Shield lake basins; Bird GA et al.; Radionuclide tracers of heavy metals (59Fe, 60Co, 65Zn, 75Se, 85Sr, 134Cs and 203Hg) representing potential contamination from nuclear power plants, industry and agriculture were added to separate basins of Lake 226, Experimental Lakes Area, northwestern Ontario . The two basins were part of a eutrophication experiment and differed in their trophic status; the north basin (L226N) was eutrophic whereas the south basin (L226S) was mesotrophic . Our objective was to determine the uptake of the radionuclides by biota and the effect of lake trophic status on their bioaccumulation . The trophic status of the lakes did not appear to have a marked effect on the accumulation of radionuclides by the biota . This may have been because of a mid-summer leakage of nutrients between the basins which enhanced primary production in L226S, because there is a time lag between primary production and the availability of the radionuclides to the fishes or because trophic status does not affect the uptake of at least some of these radionuclides . However, there was a tendency for faster uptake of the radionuclides in L226N by fish than L226S, but the differences were not significant . Concentrations in the biota generally decreased in the order: fathead minnow > pearl dace > tadpoles > slimy sculpin > leeches . Concentrations in biota generally decreased in the order . 65Zn > 203Hg > 75Se > 134Cs > 60Co > 85Sr = 59Fe . Cobalt-60 concentrations in tadpoles were greater than in the other biota . Radionuclide concentrations in the tissues of lake whitefish indicated that uptake was predominantly from food . Radionuclide concentrations were usually higher in the posterior gut, liver and kidney than in other tissues, whereas body burdens were generally high in the muscle for 75Se, 134Cs and 203Hg; kidney and gut for 60Co; and bone for 65Zn and 75Se . Mercury-203 burdens were also high in the bone and gut. Parasitol Res, 1998 Jun, 84(6), 459 - 66 Colonization and seasonality of goby (Gobiidae, Teleostei) parasites from the southwestern Baltic Sea; Zander CD et al.; A comparative parasitology study of gobiid fishes from two sites on the western Baltic Sea was done to get information on the quality of the respective environments . The parameters used were the infracommunity, the species numbers and abundance with respect to the size classes of the hosts, and the abundance with respect to the seasons . The hosts, Gobius niger, Gobiusculus flavescens, Pomatoschistus minutus, and P . pictus, were caught at Blank Eck (Kiel Bight) and Dahmeshoved (Lubeck Bight) during 1992 and 1993 . The infracommunities of Dahmeshoved attained higher rates of prevalence of helminth parasites than did those of Blank Eck, as was valid in all host specimens harboring one or two parasite species . The group bearing three parasite species was present in Dahmeshoved but absent in Blank Eck . Parasite species numbers, which were similar in the two sites, increased from the smallest to the largest hosts but changed with growth . With one exception, this result is also valid for the abundance, which clearly differed between the hosts and between the sites . Whereas species numbers as well as abundance rates were low in spring, they increased in summer . The results reveal that the composition of infracommunities depends on the local parasite fauna and on the strength of general host defense mechanisms, whereas that of the component community is dependent on the susceptibility of hosts to single parasite species and on the density of intermediate parasite stages . This is also the reason for the stronger infestation of hosts from Dahmeshoved as opposed to those from Blank Eck, where the degree of eutrophication is lower and, therefore, fewer herbivorous intermediate hosts can exist. Environ Manage, 1998 Jul, 22(4), 547 - 62 Coastal Environmental Impacts Brought About by Alterations to Freshwater Flow in the Gulf of Mexico Sklar FH, Browder JA. / Freshwater inflow is one of the most influential landscape processes affecting community structure and function in lagoons, estuaries, and deltas of the world; nevertheless there are few reviews of coastal impacts associated with altered freshwater inputs . A conceptual model of the possible influences of freshwater inflows on biogeochemical and trophic interactions was used to structure this review, evaluate dominant effects, and discuss tools for coastal management . Studies in the Gulf of Mexico were used to exemplify problems commonly encountered by coastal zone managers and scientists around the world . Landscape alteration, impacting the timing and volume of freshwater inflow, was found to be the most common stress on estuarine systems . Poorly planned upstream landscape alterations can impact wetland and open-water salinity patterns, nutrients, sediment fertility, bottom topography, dissolved oxygen, and concentrations of xenobiotics . These, in turn, influence productivity, structure, and behavior of coastal plant and animal populations . Common biogeochemical impacts include excessive stratification, eutrophication, sediment deprivation, hypoxia, and contamination . Common biological impacts include reduction in livable habitats, promotion of "exotic" species, and decreased diversity . New multiobjective statistical models and dynamic landscape simulations, used to conduct policy-relevant experiments and integrate a wide variety of coastal data for freshwater inflow management, assume that optimum estuarine productivity and diversity is found somewhere between the stress associated with altered freshwater flow and the subsidy associated with natural flow . These models attempt to maximize the area of spatial overlap where favorable dynamic substrates, such as salinity, coincide with favorable fixed substrates, such as bottom topography . Based upon this principle of spatial overlap, a statistical performance model demonstrates how population vitality measurements (growth, survival, and reproduction) can be used to define sediment, freshwater, and nutrient loading limits . Similarly, a spatially articulate landscape simulation model demonstrates how cumulative impacts and ecosystem processes can be predicted as a function of changes in freshwater, sediment, and nutrient inflows.KEY WORDS: Resource management; Landscape impacts; Freshwater discharge; Coastal, ecosystem models; Coastal wetlands Science, 1998 May 1, 280(5364), 745 - 7 Modulation of diversity by grazing and mowing in native tallgrass prairie Collins SL, Knapp AK, riggs JMB, Blair JM, Steinauer EM. Species diversity has declined in ecosystems worldwide as a result of habitat fragmentation, eutrophication, and land-use change . If such decline is to be halted ecological mechanisms that restore or maintain biodiversity are needed . Two long-term field experiments were performed in native grassland to assess the effects of fire, nitrogen addition, and grazing or mowing on plant species diversity . In one experiment, richness declined on burned and fertilized treatments, whereas mowing maintained diversity under these conditions . In the second experiment, loss of species diversity due to frequent burning was reversed by bison, a keystone herbivore in North American grasslands . Thus, mowing or the reestablishment of grazing in anthropogenically stressed grasslands enhanced biodiversity. Chemosphere, 1997 Dec, 35(11), 2589 - 601 Ela 1.0--a framework for life-cycle impact assessment developed by the Fraunhofer-Gesellschaft . Part A: The conceptual framework; Herrchen M et al.; The Fraunhofer-Gesellschaft has sponsored the development of a conceptual and flexible, computer aided tool to perform the impact assessment within LCA (life cycle assessment) for technical products and processes . The developed general framework "Ela 1.0" (environmental loads analysis) consists of four elements: the selection of appropriate impact categories, the categorization of emissions and wastes leaving the systems as well as of resource and energy consumption, the characterization and an analysis of the results of the impact assessment . The latter compares the product-based emissions with the total of emissions of a region such as Germany, the EU or OECD countries . The framework Ela 1.0 considers the environmental categories: global warming, ozone depletion, resource and energy consumption, wastes, eutrophication (including COD and BOD as measured parameters), acidification, ecotoxicity, ozone formation and human toxicity . The latter categories are handled by listing of precursors for ozone formation, and by listing of emissions scored according to their human hazard potential . The options, possibilities and limitations of the conceptual framework are presented in part A of a series of publications. Sci Total Environ, 1997 Oct 7, 205(1), 81 - 95 Nutrient profiles in the everglades: examination along the eutrophication gradient; Vaithiyanathan P et al.; We examined the concentration profiles of nutrients in the surface water, soil and pore water along the eutrophication gradient of the Water Conservation Area-2A (WCA-2A) in the northern Everglades . Phosphorus levels in the surface waters contributed by the agricultural runoff showed an exponential decrease downstream of the inflow structures attaining background values of 7-12, 7-9 and 5-6 micrograms l-1 of TP, TDP and PO4-P, respectively, at distances of 8-10 km . The pore water PO4-P concentration in the oligotrophic areas ranged between 5 and 10 micrograms l-1 . Molar ratios of dissolved inorganic N and P suggest a possible switch in nutrient limitation in the surface water from P in the oligotrophic areas to N in the eutrophic areas (DIN:DIP approximately 5) . External nutrient loading has also contributed to a three- to four-fold increase in soil TP concentration and enhanced pore water PO4-P in the northern marshes . Unlike P, C and N concentration in the soils remained fairly uniform along the eutrophication gradient . 210Pb dating of soil cores suggests that the increase in soil P concentration (from < 500 to 1500 micrograms g-1) and P accumulation rate (from 0.06 to 0.46 g P m-2 per year) at the eutrophic site correlates with the installation of inflow structures in 1960-1963 through which agricultural drainage from the Hillsboro canal enters the marshes . Organic P makes up 70-90% of the total P in the soils as uptake by algae and macrophytes is the primary mechanism of P removal in these wetlands . Calcium supply from the underlying bedrock suggested from the surface and pore water chemical profiles has important consequences for P-cycling in the Everglades as Ca-bound P is the major form of inorganic P storage in the soils. Rev Environ Contam Toxicol, 1997, 152, 85 - 111 Environmental fate of EDTA and DTPA; Sillanpaa M; EDTA can be extremely persistent in WWTP and also in natural waters; DTPA seems more biodegradable . However, the biodegradability of DTPA might be of negligible significance as EDTA, and in some cases also DTPA, are generally found in the receiving waters of many industrial areas, thus being classified as one of the major organic pollutants discharged in waters . The photochemical degradation of Fe(III) complexes of these compounds is documented, but the extent to which these results can be applied to natural waters is not clear . There exist still some uncertainties in the chemical speciation, adsorption, overall degradation, and ultimately the eutrophication effect of EDTA and especially of DTPA . It can be inferred that EDTA can affect the essential and nonessential metal balance in natural waters as well as in aquatic organisms, even in the long term . The estimation of the chemical speciation of EDTA and DTPA in natural waters is a challenging task because of of the complexicity of the system and should be based not only on equilibrium calculations but also on direct analytical determinations of diverse metal species . Unfortunately, analytical methods for speciation studies at environmentally relevant concentrations are not available . Also, monitoring of EDTA or DTPA in sediments and solid particles has not been initiated . EDTA and DTPA are not expected to be acutely toxic to aquatic organisms . On the other hand, in natural waters, several compounds affect organisms simultaneously . Therefore, EDTA and DTPA can contribute to the aquatic toxicity at significantly lower concentration than those determined by short-term toxicity tests . Also, more studies should be directed to estimating chronic effects, including the possible imbalance of body calcium in animals and other organisms . EDTA and DTPA can certainly desorb heavy metals bound to sediments and also prevent heavy metal sedimentation, thus increasing their cycle in water . However, these metal complexes are not expected to be as bioavailable as a free metal ions . Taken together, EDTA and DTPA, being persistent compounds, contribute to the general chemicalization of the aquatic environment . They can also cause several indirect and, under extreme circumstances, direct effects in the aquatic environment . Thus, their release into natural waters should be minimized wherever possible. Environ Manage, 1997 Sep, 21(5), 725 - 32 RESEARCH: Are Recent Watershed Disturbances Associated with Temporal and Spatial Changes in Water Quality of Lake George, New York, USA? Momen B, Eichler LW, Boylen CW, Zehr JP. / Lake George, a mesooligotrophic lake, is a historically important recreational site in northeastern New York, USA . A preliminary analysis of the data, collected during 1980-1990, suggested that the indicators of primary productivity have increased, particularly in the southern basin of the lake . This change was attributed to the recent increases in the urbanization and development of the southern shorelines . The suggestion of temporal and spatial degradation in lakewater quality has caused substantial concerns among the decision makers and the public alike . The main objective of this study is to evaluate possible eutrophication of the lake by quantification of temporal and spatial trends in concentrations of total phosphorus (TP), chlorophyll a (Chl a), silica (Si), and chloride (Cl) through the use of proper statistical techniques . Results indicate no statistically significant changes in the concentrations of TP, Chl a, or Si in the spring or summer from 1981 to 1993 . A significant temporal trend of increase in Cl concentration is, however, detected . This is perhaps the strongest evidence that the development of the Lake George watershed has affected lakewater chemistry . In spring, the concentrations of TP, Chl a, Si, and Cl, averaged over all 13 years, were higher in the south basin, but differences are not statistically significant (i.e., P > 0.05) . In summer, Si was slightly but significantly lower, and Cl was nonsignificantly higher in the south basin . Significant interactions between temporal and spatial changes are detected based only on summer values of TP and Chl a, indicating differential trends of change for these two variables in the south and north basins during the last 13 years.KEY WORDS: Repeated-measures ANOVA; Split-plot design; Lakewater chemistry; Lake George New Microbiol, 1997 Jul, 20(3), 253 - 76 Effect of treated sewage on the water quality and phytoplankton populations of Lake Manzala (Egypt) with emphasis on biological assessment of water quality; el-Naggar ME et al.; The effect of treated sewage on the quality of water and phytoplankton populations of Lake Manzala was studied with emphasis on use of algae to monitor water pollution as part of a search for a biological assessment of water quality . Lake Manzala is situated at the northern part of the Nile-delta, Egypt . Disposal of treated sewage into Lake Manzala appeared to have differential effects on water quality and phytoplankton populations . Marked seasonal and local variations were observed for the physical and chemical characteristics of water . 157 species of algae were identified, 59 Chlorophyta, 37 Bacillariophyta, 30 Cyanophyta (Cyanobacteria), 28 Euglenophyta, one Pyrrhophyta and 2 Cryptophyta . Distribution and abundance of these algal divisions were found to differ at different sampling stations . Qualitative and quantitative growth of each algal division displayed great seasonal variations . The phytoplankton standing crop was mainly due to the contribution of Bacillariophyta whereas the species composition is dependent mainly on Chlorophyta . A great parallelism was noted between the quality of water samples based upon the chemical and physical investigations and their quality based upon the biological indices . Compound eutrophication index indicated that the nature of the investigated water ranged between eutrophic and hypereutrophic conditions . Diversity index values indicated that the water in the study area was of a moderate level of pollution . Saprobic index and saprobic quotient revealed the presence of beta- to alpha-mesosaprobic forms of algae. Nat Toxins, 1997, 5(2), 64 - 73 Microcystins in Slovene freshwaters (central Europe)--first report; Sedmak B et al.; Cyanobacterial blooms are frequent in the North-Eastern region of Slovenia, where the agricultural activities are intensive, resulting in higher water eutrophication . In a two year monitoring program we identified eighteen blooms of cyanobacteria, fifteen being hepatotoxic by intraperitoneal mouse bioassay . The approximate LD100 varied from 50-1000 mg/kg (dry cell weight/animal weight) and gross pathological signs were characteristic of cyanobacterial hepatotoxins . Frequently the blooms were dominated by the most common and cosmopolitan species Microcystis aeruginosa . Other bloom forming species were M . wesenbergii, Oscillatoria rubescens, Anabaena flos-aquae, and Aphanizomenon flos-aquae . Using high-performance liquid chromatography (HPLC), three hepatotoxins were identified, microcystin RR being the most frequent and present in highest amounts, LR, and YR . The phytoplankton analysis revealed that several different species of cyanobacteria were present in the water bodies at the time of the blooms . Although present in various water bodies, filamentous bloom-forming cyanobacteria had no chance to proliferate in the presence of the colonial genus Microcystis . In individual cases we were faced with a bloom in the bloom, meaning that various Microcystis aeruginosa blooms were heavily contaminated with another cyanobacteria, Phormidium mucicola which infested the mucilage of the chroococcal species. Toxicon, 1996 Nov-Dec, 34(11-12), 1385 - 92 Development of a protein phosphatase-based assay for the detection of phosphatase inhibitors in crude whole cell and animal extracts; Honkanen RE et al.; Diarrhetic shellfish poisoning (DSP) is a serious and globally widespread phytoplankton-related seafood illness . Although DSP is rarely life-threatening, it causes incapacitating diarrhea and vomiting with no known medical treatments . In addition, phytoplankton producing DSP toxins have been identified in temperate coastal waters worldwide, and their numbers may be increasing as a result of coastal eutrophication . The toxic effects of the major DSP toxins, okadaic acid and dinophysistoxin-1 (35-methylokadaic acid), appear to originate from their inhibitory activity against a family of structurally related serine/threonine protein phosphatases (PSPases) . In particular, the inhibition of essential PSPases (e.g . PP1 and PP2A) has catastrophic consequences in most eukaryonic cells . Exploiting the potent inhibitory property of the DSP toxins, we have developed an enzyme-based assay (PP2A assay) capable of detecting both okadaic acid and dinophysistoxin-1 in nanogram amounts . The assay employs purified PP2A, which has an extremely high affinity for both DSP toxins . This provides the PP2A assay with a level of sensitivity comparable to, or surpassing, that of most monoclonal antibody probes . To evaluate the PP2A assay as a means of detecting contaminated shellfish, a series of spike recovery experiments was conducted . The findings from these studies suggest that the PP2A assay has the potential for development into a rapid and relatively simple method for detecting PSPase inhibitors in crude extracts produced from shellfish. Rev Biol Trop, 1996 Aug, 44(2A), 395 - 416 The use of water chemistry and benthic diatom communities for qualification of a polluted tropical river in Costa Rica; Silva-Benavides AM; The water quality of several sections of a tropical river subjected to severe pollution was studied through physico-chemical water analysis and benthic diatom assemblages . The methodology follows the concept of differential species groups and that of its modification for the groups of nutrient-differentiating species for rivers rich in both oxygen and inorganic nutrients . The trophic indication of the latter authors correspond clearly with the results of chemical observations made in this study . The most abundant species found in this river were Navicula goeppertiana, Gomphonema parvulum, Gomphonema sp . aff . pumilum, Nitzschia palea, Nitzschia amphibia, Nitzschia clausii Nitzschia inconspicua, Navicula seminulum, Navicula sp . aff . cryptocephala, Navicula schroeterii var . escambia, Cymbella sinuata and Surirella sp . aff . roba . These species are known to be tolerant to organic pollution and eutrophication . Therefore we may conclude that diatoms are useful for biological monitoring of disturbed tropical rivers. J Appl Toxicol, 1996 Mar-Apr, 16(2), 153 - 6 Effects of N,N-dimethylnitrosamine (DMNA) on in vitro oocyte maturation and embryonic development of fertilized eggs of carp (Cyprinus carpio L.) kept in eutrophied ponds; Bieniarz K et al.; Toxic effects of N,N-dimethylnitrosamine (DMNA) at doses of 100 or 500 micrograms l-1 on in vitro carp oocyte maturation (steroidogenesis), embryonic development and hatching of larvae (obtained as a result of artificial spawning of females kept for four seasons in normal and eutrophicated ponds) were investigated . There were no significant effects of DMNA on oocyte maturation and steroidogenesis during 24 h of incubation . The DMNA decreased the hatching of fertilized eggs derived from control females . This decrease reached a level of significance at a dose of 500 micrograms l-1 . However, the effect of long-term exposure of female fish to eutrophied water was very much higher . The trend of the in vitro DMNA effect was the same, but it did not reach a statistically significant level . The results suggest that nitrosamines, through their effect on egg hatchability, may reduce fish populations along with increasing aquatic eutrophication. Biomed Environ Sci, 1996 Mar, 9(1), 46 - 51 Promoting activity of microcystins extracted from waterblooms in SHE cell transformation assay; Wangth HB et al.; Microcystis aeruginosa is the dominant algae in most of the eutrophicated lakes in China . It can produce cyclic heptapeptides, known as microcystins, which can cause liver damage in wild and domestic animals . In this paper, a two-stage transformation assay for demonstrating the carcinogenic effects of the algal toxins is reported . The cell strain used in this assay was derived from embryos of Syrian golden hamster and the algal toxins were extracted from Microcystis aeruginosa, termed microcystis raw toxin (MRT) . To elucidate its promoting activity, the target cells were first exposed to a low dosage of 3-methylcholanthrene (MCA) and then to MRT . The results showed that MRT significantly enhanced the MCA initiated cell transformation, and a dose-response relationship was observed, but it failed to induce transformation of SHE cells not pretreated by MCA . These results suggest that the MRT play an important role in the malignant transformation of SHE cells . MRT may thus be a tumor promoter, and this transformation assay with SHE cells may be used to predict tumor prompting activity of environmental chemicals, before long-term in vivo two-stage carcinogenesis experiments are carried out. Bull World Health Organ, 1996, 74(2), 159 - 63 {Cercarial dermatitis in Europe: a new public health problem?}; de Gentile L et al.; Cercarial dermatitis is a parasitic impasse that has worldwide distribution . The condition manifests itself as a highly pruriginous skin rash and is due to penetration of the dermis by larval stages (furcocercariae) of avian trematodes . Many species may be responsible for this disease . In Europe the genus Trichobilharzia is widely represented, in particular by the species T . ocellata; the definitive host is the duck (Anas platyrhinchos); the intermediate hosts are snails of the genus Lymnea (L . ovata or L . stagnalis) . In France, cases of cercarial dermatitis were reported in June and July 1994 to the health authorities of three departements in the Pays de la Loire Region (western France) . The epidemiological situation, common to the three maintained ponds that were concerned, is as follows: high level of eutrophication of the sites, colonization of the ponds by L . ovata, and settlement by many duck colonies . The simultaneous occurrence of these three phenomena, combined with long hours of sunshine in the summer, is responsible for most of the foci of cercarial dermatitis recently described in Europe . Control of this condition is difficult, requiring strict maintenance of bodies of water and if necessary the use of molluscicides such as niclosamide . The use of praziquantel in baits for treating the definitive hosts appears to interrupt the natural cycle of the avian Schistosomatidae . In the light of the observations reported here and the analysis of recent publications, cercarial dermatitis may be regarded as an emerging disease . Its public health impact needs to be evaluated at the global level. Arch Toxicol Suppl, 1996, 18, 417 - 34 Ataxonomic assessment of phytoplankton integrity by means of flow cytometry; Steinberg CE et al.; Flow cytometry, a method well established in medicine and biotechnology, can also make an important contribution to (applied) limnological as well as ecotoxicological studies on phytoplankton . Flow cytometry can, for instance, contribute to the ataxonomic structural and functional assessment of phytoplankton . This approach may serve as a supplement to the well-established taxonomic evaluation by means of various microscope techniques . We present some examples for such ataxonomic phytoplankton evaluation . These examples include phytoplankton of eutrophicated and acidified water bodies as well as slowly flowing rivers . Phytoplankters may be differentiated by their pigment contents into carotinoid-rich ones (such as Chrysophyceae, Bacillariophyceae, and Dinophyceae) and carotinoid-poor ones (such as Euglenophyceae and Chlorophyceae) . As a useful biomass parameter of phytoplankton algae we tested successfully protein staining by fluorescein isothiocyanate . We discuss the advantage of this approach as compared with results obtained by Coulter counter or by biomass calculations from microscope analyses . Up to now, evaluation of the biological quality of pelagic water bodies is still laborious and time consuming because of the microscopical examination of planktic communities usually practiced . As a possible improvement we present a structural ataxonomic approach for assessing the integrity of individual phytoplankters (on the basis of physiological parameters) as well as of the phytoplankton communities that is based on annual means of biomass spectra . Flow cytometry can provide considerable relief. Mem Inst Oswaldo Cruz, 1995 Mar-Apr, 90(2), 195 - 204 The snail hosts of schistosomiasis: some evolutionary and ecological perspectives in relation to control; Thomas JD; Despite opportunities for radiation provided by spatio-temporal isolation, the basic morphological plan of pulmonate snails has remained conservative . In consequence of the resulting dearth of morphological characters and their plasticity, there is a case for using biochemical characters such as exogenous chemicals released by the snails (e.g . amino acids) and their chemoreception niche as taxonomic aids to classify snails of medical importance . As these same chemicals are used by snails to distinguish conspecifics they could also be used as "environmental antibodies" in controlled release formulations (CRF's) designed to remove target snails in a specific, cost-effective and ecologically acceptable manner . The snails, surface-living bacteria, algae and macrophytic plants are considered as co-evolved, interactive modular systems with strong mutualistic elements . Recently, anthropogenic perturbations such as deforestation, and damming of flowing waters, have benefited these modules whereas others such as river canalization, acid deposition, accumulation of pesticide residues and eutrophication have harmed them . Research is needed to elucidate the factors which limit the growth of snails in primitive habitats, uninfluenced by man, as well as in those subject to harmful anthropogenic factors . The understanding thus gained could be applied to develop cost-effective primary health care strategies to reduce or prevent transmission of schistosomiasis and other water related diseases. Toxicon, 1994 Oct, 32(10), 1270 - 4 Toxic effects of water eutrophication on pancreatic, hepatic and osteogenic tissues of rats; Novelli EL et al.; Pollution, industrial solvents, concentrations of metals and other environmental agents are widely related to biochemicals values which are used in disease diagnosis of environmental toxicity . A rat bioassay validated for the identification of toxic effects of eutrophication revealed increased serum activities of amylase, alanine transaminase (ALT) and alkaline phosphatase (ALP) in rats that received algae, filtered water and nickel or cadmium from drinking water . Serum Cu-Zn superoxide dismutase activity decreased from its basal level of 40.8 +/- 2.3 to 26.4 U/mg protein, at 7 days of algae and at 48 hr of nickel and cadmium water ingestion . The observation that lipoperoxide concentration was not altered in rats treated with filtered water, while amylase, ALT and ALP were increased in these rats and in those treated with nickel or cadmium, indicated that pancreatic, hepatic and osteogenic lesions by eutrophication were not related to superoxide radicals, and might be due to a novel toxic environmental agent found in filtered and non-filtered algae water. Eisei Shikenjo Hokoku, 1994, (112), 1 - 16 {New regulation of tap water quality and exposure assessment}; Ando M; Recently, social concerns regarding tap water quality have increased, mainly because of the possible reduction in safety due to contamination of tap water by various chemicals and more frequent occurrence of the strange odors and tastes in as a result of resource water eutrophication . Consequently, the Ministry of Health and Welfare conducted a detailed two-year investigation of the Water Quality Standards of the Water Works Law by summoning an expert committee, and as a result, totally revised the Standards in December 1992 . This was the first overall revision since 1958 when the Water Quality Standards were established, and an additional 21 items, including mainly hazardous chemicals including pesticides and chlorinated by-products, were newly added . Values and testing methods are now listed for 46 items, and the Law obliges every water supply to conduct periodical water testing for the necessary items almost every month with ad-hoc testing, as required of hydrants . Simultaneously, 26 monitoring items are listed in hazardous contaminants guidelines which should be checked, when necessary . The new Water Quality Standards and the guidelines were brought into force in December 1993, and the quality of all parts of the water supply is now tested in accordance . Risk assessment is a scientific process that includes some form of measurement as one of its central elements . In many cases, the measured parameter is the level of exposure to a hazard . Also, measurements are essential in establishing the quantitative relationship between exposure and response, and in determining natural baseline conditions in the environment . Exposure assessment is the process of measuring or estimating the intensity, frequency, and duration of human or other population exposures to risk agents . Exposures may occur in a variety of ways, such as through ingestion, dermal contact, or inhalation . For many risk assessments, exposure assessment is the most difficult task . The reason for this is that exposure assessment often depends on factors that are hard to estimate and for which there are few data . Critical information on the conditions of exposure is often lacking . To be comprehensive, an exposure assessment must describe the levels of exposure and all conditions that might be needed to assess the effects of such exposures, including their magnitude, duration, schedule, and route . This report presents the various problems covered in exposure assessment relevant to monitoring, testing, and methodology. Int J Health Serv, 1993, 23(3), 519 - 39 Population, development, and the environment: trends and key issues in the developed countries; Commoner B; The quantitative relationship between environmental degradation (pollution) and the factors that influence it can be expressed by the identity: Pollution = population x (good/population) x (pollution/good), where "affluence" is expressed as good/population and the technology of production as pollution/good . Annual data for the emission of carbon monoxide and nitrogen oxides from mobile sources and for the use of pesticides and inorganic nitrogen fertilizer from agriculture, for the member countries of the Organization for Economic Cooperation and Development and the United States, were analyzed to determine the relative change in the three factors over the period 1970-1987 . In each case the considerable variation in pollutant emissions among the different countries is most closely related to the concomitant change in the technology factor (pollution/good) . In contrast, there is much less variation among the countries in the population and "affluence" factors, which are consequently uncorrelated with the variation in pollutant emissions . The data show that the change in production technology is by far the most important of the several factors responsible for changes in pollution emissionPIP: The notion of "pollution per capita" has obscured the role of technology in production, which governs the impact of population and economic development on the environment . The common view has been that population growth affects economic development which, in turn, affects the environment . A more accurate representation would be that population affects production technology which affects both economic development and the environment . Various technologies affect economic development and the environment differently . Photochemical smog, toxic chemicals, rapid eutrophication, hazardous waste and trash disposal have all been transformed by production technologies since World War II . Environmental improvement in developed countries must entail changes in decisions made about the design of systems of production . Ecologically sound economic development requires transforming the means of production . Data on carbon monoxide (CO) and nitrogen oxide (NO) emissions from automobiles for 1970-87 were obtained from the Organization for Economic Cooperation and Development and analyzed . The magnitude of change in vehicles per km, in CO emissions, in population, in vehicle-km per population, and in CO emissions per vehicle-km showed that changes varied over time by country . The technology impact on CO emissions improved in every country . When the PAT equation was converted to logarithm form, the result indicated that population change had little impact on CO emissions in developed countries . Although the changes in the "affluence factor" were great, the impact on CO emissions was limited and the major impact was from technology . In only four countries was the impact of annual CO emissions too small to affect the impact of population growth and the increase in traffic: Norway, France, Italy, and the United Kingdom . However, NO emissions, which result from high compression engines of passenger cars and which cannot be controlled with exhaust control devices, have increased in every country . Changes in population had a smaller effect on NO emissions than affluence or technology . Technology had the strongest impact on NO emissions; the impact of technology varied by country . Similar analysis of inorganic nitrogen fertilizers and pesticides showed the strong impact of technology . J Egypt Public Health Assoc, 1993, 68(5-6), 593 - 615 Phosphorus-nitrogen loading and trend of fish catch as index of lake Mariut eutrophication; Thomas GH et al.; Lake Mariut was considered in the past to represent an important source of fish production in Alexandria especially during the periods which were characterized by low catch from its marine fisheries . The growing population in Alexandria and the expanding industries around the lake were accompanied with increased quantities of domestic and industrial wastes discharged annually into the lake proper . These quantities were increased from 192 million cubic meters in 1974 to about 300 million cubic meters in 1992 . Consequently, the water quality in this basin was highly deteriorated and changed to become markedly eutrophic . High input of nutrients through sewage and industrial wastes has considerably increased the phosphorus and nitrogen load in the lake proper . Phosphorus and nitrogen loading in this basin were estimated in 1992 to be 60.2 gm/m3 P/y and 79.8 gm/m3 N/y . According to the nutrient concept given by Vollenweider (1974), these two figures have provided an evidence that the lake proper was strongly changed from oligotrophic to polytrophic phase . The trend of its total fish catch as well as the trend of different fish categories catch during the period 1970-1992 also confirms its eutrophication . This is in addition to bad changes that took place with respect to environmental conditions due to the continuous inflow of domestic and industrial wastes from different sources into this part of Mariut lake . Marginal increments of the lake proper total catch were decreased from 20.6% in 1970 to -28.8% in 1992, while the marginal increments of Tilapia sp., Clarias sp, Anguilla sp . and Mugil sp . were decreased from 21.4%, 14.3%, 29.8%, and 28.9% respectively in 1970 to -29.1%, -25.3%, -43.0%, and -36.8% in 1992 . Based on these two indices of the lake proper eutrophication, the expected improvement of its environmental conditions will take several years after treating all inland discharges flowing into the lake and/or diverting all relevant outfalls away from this basin. Sci Total Environ, 1992, Suppl, 631 - 62 Eutrophication, marine biotoxins, human health; Viviani R; Eutrophication phenomena in marine coastal waters can today be explained on the basis of natural or anthropogenic causes . Undesirable effects and also sanitary problems in both types of eutrophication are often produced, but they may differ greatly in frequency and significance . Some algal biotoxins can affect both marine animals and man, whilst others affect man alone . From data currently available it appears that the sanitary state of man can be affected through the digestive, respiratory and cutaneous apparatus . Four main dinoflagellate biointoxications are now recognized: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), diarrhoetic shellfish poisoning (DSP), and venerupin poisoning . Other biointoxications are due to a diatom bloom responsible for amnesic shellfish poisoning (ASP) and to blue algae blooms which have effects on the skin and the respiratory tract . All these marine toxins are considered and particular attention is paid to: producing organisms, chemistry of the components, compromised sea foods, methods of analysis, occurrence worldwide, human intoxications, toxicology and mechanism of action on a molecular level, therapeutical notes, tolerance levels and remarks on safety . Attention is also paid to the relationship between the anthropogenic eutrophication and PSP and DSP since these are the most widespread biointoxications from toxic marine dinoflagellates in the world today and for which the European Economic Community (EEC) is proposing health legislation such as tolerance limits and methods for official analysis . In view of the harmful potential of coastal anthropogenic eutrophication, the main current committment of various countries concerns control . Finally, it is important to develop a suitable monitor research system using all the specific standards of allowed toxic substances, and also research on effective antiodotes against all biotoxins. Rev Sci Tech, 1991 Sep, 10(3), 629 - 54 {The role of nitrogen and phosphorus in pollution of animal origin}; Audoin L; Despite some variability in the data, the author has been able to establish the average characteristics of animal wastes, and to formulate an overall view of nitrogen and phosphorus wastes originating from livestock, in order to compare them with other wastes . Nitrogen is originally present mainly in the form of dissolved ammonia, whereas phosphorus is present in inorganic particles . Ammonium nitrogen is toxic for the aquatic fauna and, in favourable conditions, can be oxidised into nitrates and nitrites, which are undesirable constituents, capable of affecting the health of consumers . Phosphorus and nitrogen compounds in excess of the requirements for soil fertilisation are responsible, among other things, for degrading the quality of surface water, leading to eutrophication. J Parasitol, 1991 Aug, 77(4), 551 - 6 The effects of periodic eutrophication on parasitism and stock identification of Trematomus bernacchii (Pisces: Nototheniidae) in McMurdo Sound, Antarctica; Moser M et al.; McMurdo Sound, Antarctica, is suited for the study of the effects of eutrophication on diet-related parasites of Trematomus bernacchii (Boulenger, 1902) (Pisces) . It has been relatively well studied, the environment is predictable, and there are significant differences in primary productivity over small distances . The differences in parasitism for 5 helminth species can be attributed to the enrichment processes in the sound . The prevalences of the acanthocephalan Echinorhynchus sp., the nematode Ascarophis nototheniae, the digenean Dinosoma sp., and the cestode Phyllobothrium sp . are significantly higher on the east side of the sound than on the west . The prevalence of the digenean Lepidepedon garrardi was significantly higher on the west side . We believe that the differences in the prevalences of infection between the east and west sides suggest that at least the benthic, adult fish do not readily move from one side of the sound to the other . We report the following (new host records are marked by asterisks): Echinorhynchus sp., Corynosoma hamanni (Acanthocephala); Phyllobothrium sp., Diphyllobothrium sp., Trypanorhyncha (Cestoidea); Clavellopsis (Copepoda); Dinosoma sp., Lepidepedon garrardi (Digenea); Pseudobenedenoides brachicola, Polyopisthocotylea (Monogenea); Contracaecum sp., Ascarophis nototheniae (Nematoda); Myxoproteus sp., Henneguya sp., Ceratomyxa sp., and Zschokkella sp . (Protozoa). Offentl Gesundheitswes, 1991 Mar, 53(3), 138 - 43 {Swimmers' dermatitis in an excavation pool--an incentive for the status analysis of the water and for the preparation of an ecology-friendly utilization concept}; Allgower R et al.; In recent years, swimmer's itch occurred in several ground water lakes dud excavation pools in sporadic or epidemic outbreaks in the upper Rhine valley . They were caused by Trichobilharzia szidati . The Public Health Offices in Offenburg and Freiburg have been dealing extensively with this problem . They were also requested to comment on the use of lakes within a framework for regional development (Landschaftsrahmenplan) by the Southern Upper Rhine Regional Authority . An ecological study of water quality was prepared in summer 1989 in Offenburg . Hydrological and biological criteria were applied . Eutrophication due to excessive nutrient input proved to be the main problem . Measures for reduction were proposed that also included determining water use . Thus, specific use should either be prescribed from the beginning for each lake and made possible via ecologically oriented long-term maintenance measures, or use should be adapted to the natural succession process . Thus, after gravel quarrying, water sports including bathing would be possible, followed by fish farming and finally reservation as protected area. Angew Parasitol, 1990 May, 31(2), 95 - 9 An outbreak of bucephalosis in fish of the Main river; Hoffmann RW et al.; High losses due to metacercaria of Bucephalus polymorphus especially in cyprinids were observed in summer 1984 during a period of a sudden increase in water temperature . Pathology of diseased fish is described . Factors, such as eutrophication of the water system and overcrowding of distinct fish species, are discussed to be the main causes provoking outbreak of the parasitosis. Sci Total Environ, 1989 Jan, 78, 59 - 75 Environmental stress in five aquatic ecosystems in the floodplain of the River Rhine; Admiraal W et al.; General theories of stress ecology were applied to aquatic communities in the floodplain of the polluted River Rhine . These communities inhabited (i) a brackish section of the Ems-Dollard estuary with large intertidal flats, (ii) the coastal waters of the North Sea and the adjacent Wadden Sea, (iii) a former estuary of the Rivers Rhine and Meuse: the newly endiked Lake Grevelingen, (iv) the shallow Loosdrecht Lakes, and (v) the lower River Rhine . These systems are characterized by natural perturbations, such as suspension of sediments and flushing of the shallow waters . Organic pollution, eutrophication and chemical pollution reinforce the natural tendency to severe selection in the communities, in extreme cases leading to an abundance of small and opportunistic species participating in relatively simple food chains . Signs of ecosystem distress, as defined by Rapport et al., were detectable in all five ecosystems . The application of the theory of Odum et al . on stimulation and inhibition of ecosystems helped in identifying the positive impact of man . The role of stress in natural aquatic ecosystems in the delta, together with observations on ecological recovery under reduced man-made perturbation, suggest that there is scope for effective water management that exploits the resilience of these ecosystems. Vet Med Nauki, 1987, 24(5), 91 - 6 {Content of chemical elements in the liquid manure of swine at a treatment plant using biological purification}; Baikov BD et al.; An atom absorption spectrophotometer was used to study 13 chemical elements in samples taken at the entrance of the purification station, at the mechanical step exit, at the biostep exist, and at the laguna exit as well as following treatment of the solid fraction in open surface purification and drying plots . It was found that part of the biogenic chemical elements remained in the liquid fraction after purification and were hazardous in terms of eutrophication of the water receptacle . A technology was worked out to treat the solid fraction, however, it did not provide for preserving the biogenic chemical elements . This lowered the qualities of the fraction in enriching the soil. Biol Bull Acad Sci USSR, 1979 Jul-Aug, 6(4), 487 - 93 Reaction of freshwater phyto- and zooplankton to pesticides; Braginskii LP et al.; The reaction of plankton to the toxic effect of pesticides is considered at four levels: the cell, the organism, the population, and the biocenosis . The basis for the methodological approach to evaluation of response at the cell level was the principle of phase reactions . Depending on concentration, the pesticides may either suppress or stimulate the plankton organisms . Temperature may be decisive intoxic effects (pesticides are effective in a range of 15 to 25 degrees C) . Most pesticides having algacidal activity are effective in a range of concentrations of 1-10 mg/liter . Phytoplankton as a whole has a high buffer capacity with respect to pesticides . Changes in ratios of basic components of phytoplankton effected by pesticides most often lead to a change of the dominant . Analogical changes are characteristic also for zooplankton; pesticides lead to the elimination of water fleas from its composition . The stimulating effect of a low concentration of pesticides, changes in the functional activity of the components of bacterial plankton, and changes coupled with this in biogeochemical cycles of nitrogen and phosphorous as well as elimination of water fleas from the plankton promotes the development of "secondary" eutrophication, that is, an increase in the biomass of the phytoplankton. Science, 1979 Jun 8, 204(4397), 1081 - 2 N-formyliminodiacetic acid, a new compound from the reaction of nitrilotriacetic acid and chlorine; Spanggord RJ et al.; It has been proposed that nitrilotriacetic acid be substituted for trisodium polyphosphates in detergents as a way to reduce the rate of eutrophication in the Great Lake Basin . The reaction of nitrilotriacetic acid with chlorine-containing solutions produces a hitherto unknown degradation production, N-formyliminodiacetic acid, in high yield . The toxicological and environmental implications of this reaction are unclear. Ecotoxicol Environ Saf, 1977 Dec, 1(3), 311 - 26 Fertilizers for food production vs energy needs and environmental quality; Olson RA; The world is experiencing an energy crisis that is restrictive to agricultural requisites production at the same time that food is becoming increasingly short on a global basis . Fertilizers are the most energy demanding of these inputs and have become very expensive and intermittently short in supply with the reduced availability of fossil fuels . They have been indicted, furthermore, as environmental pollutants due to their presumed role in eutrophication and in being a source of excessive NO3-N that may accumulate in some leaf crops and in drinking waters . Exponential growth in fossil fuel consumption cannot continue . Economies can be made in the agricultural sector, which does indeed consume substantial quantities of energy . The energy consumed in this very essential food-producing process, however, is almost insignificant compared with that involved in transport and processing of food beyond the farm and with other energy expenditures in modern society . A shift in priorities will certainly be required in adapting to the real world of the 1970s if man's first need is to be met . Economies in fertilizer use can be made by adherence to known agronomic principles . Savings in fossil fuel energy can probably be effected also in the production of N fertilizer, by far the most fossil-energy-demanding process in the realm of agriculture . Considerable research remains to be done, however, under varied climatic conditions for understanding and controlling processes by which residuals from fertilizers may become environmental pollutants . The various issues in this paper must be resolved promptly in consideration of the now-existing energy crisis and the imminent world food crisis. Ciba Found Symp, 1977 Sep 13-15, (57), 201 - 28 Phosphorus and the eutrophication of lakes--a personal view; Reynolds CS; The availability and abundance of biologically-active forms of phosphorus in natural waters are briefly reviewed in relation to the requirements, growth and development of algal populations . The consequences of artificial enrichment of lakes with agricultural, domestic and industrial effluents ('eutrophication') attributed to increased phosphorus loading are compared with evidence from a selection of natural lakes and experimental systems in the UK . The suggestion is made that increased loadings on richer lakes make relatively less impact than does mild eutrophication of unproductive waters . Within limits the effects of eutrophication are reversible. Rev Biol Trop, 1976 Jun, 24(1 Suppl), 87 - 112 Ecological aspects of water impoundment in the tropics; Goldman CR; Recognition of the potentially harmful effects of water development in the tropics had led to increasing efforts to assess the environmental impact of such projects prior to construction . Decisions regarding the development or non-development of water resources must be based on sound investigation of both the long-and short-term effects of reservoir construction and operation . The environmental effects of water impoundment vary greatly with the characteristics of the region as well as the type of reservoir to be constructed (area and depth of reservoir, ratio of water inflow to storage) . Of major concern are the reduction of reservoir capacity as sediments accumulate behind the dam and the loss of these sediments to downstream agriculture and fisheries . The potential impact of altered flow regimes, siltation, reduction in beach formation and nutrient enrichment at the mouths of rivers, and the possibility of saltwater encroachment should receive careful stdy . A thorough description of the plants and animals to be affected by inundation should be made to determine the possible loss of rare or key organisms as well as the potential development of "nuisance species" . Included in this survey should be a detailed study of existing fish and the potential for commercial fishery development in the proposed reservoir . Consideration should be given to vegetation removal in the reservoir basin prior to inundation, since decaying vegetation can result in deoxygenation, formation of hydrogen sulfide, possible development of suitable habitats for undesirable species and snagging of fish nets . Sanitation and land use practices as well as erosion in the watershed surrounding the reservoir must be controlled to prevent accelerated eutrophication caused by increased nutrient loading . Inundation in tropical areas can have serious sociological and human health implications including the increase of diseases, e.g., malaria, schistosomiasis, onchocerciasis, and dysentery, and the probable resettlement and alteration of land use practices . Census information and surveys concerning land use, housing and health standards and the social and economic structure of the community to be affected must be evaluated in order to anticipate and avoid potential problems . The archaeologic, historic, scenic and recreational value of the site to be inundated must also be considered . Studies of the EL Cajon site on the Sula River in Honduras and the Purari River Project in Papua, New Guinea, are utilized as examples in this report.
|
© 2005
Transgalactic Ltd (manufacturer of Bioscreen C software) |
Privacy Statement | P.O. Box
1393, 00101 Helsinki, Finland,
Last modified: May 25, 2005
| ||||||
