Recently, there has been an increase in studies focusing on an emerging class of organic contaminants, hydroxylated PCBs (OH-PCBs) and chlorinated phenolic compounds (CPCs) in the environment, particularly in northern regions of Europe and Canada. Since information for fish from the Great Lakes are scarce, we determined the blood plasma ...

The results of measurement of polychlorinated biphenyls (10 PCB congeners recommended by AMAP) in surface bottom sediments collected from 26 remote lakes in Northern Norway and 11 lakes in North Russia in 1994 and 1995 are presented. Cores were collected from the deepest part of each lake with a gravity ...

Previous laboratory studies have demonstrated that estrogenic and antiandrogenic chemicals can alter several sexual characteristics in male poeciliid fishes. Whether similar disturbances occur under field conditions remains to be confirmed. Lake Apopka, Florida, is contaminated with numerous chemicals, some of which possess endocrine-disrupting activity. Male mosquitofish (Gambusia holbrooki) were collected ...

Caridina nilotica, a freshwater atyid prawn, is a vital component of the Lake Victoria ecosystem. Despite its important role in the food web leading to Nile perch, the diet of Caridina is not well understood. Caridina freshly collected from the inshore littoral and offshore plankton of Lake Victoria were cultured ...

This study tests a whole-lake experiment to reduce the bioaccumulation of radiocaesium (137Cs) in fish in lakes contaminated by the Chernobyl accident. In many lakes in the Chernobyl contaminated areas, radiocaesium activity concentrations in fish are still significantly higher (up to 100 times in some species) than acceptable limits for ...

Lake Ontario, bordering both Canada and the United States, is the only Great Lake with persistent, significant levels of mirex in its biota. Some models suggested that it would take hundreds of years before mirex disappeared from the ecosystem. From 1977 to 1996 the mirex concentrations in coho and chinook ...

The different use of P-resources between two sites in the deep oligotrophic Traunsee was studied by seasonal and vertical patterns of phytoplankton and nutrients from 12/1997 to 10/1998. The P-resources were evaluated from the proportion between the P-fractions, the dissolved reactive P (DRP), dissolved non-reactive P (DOP) and particulate organic ...

The U.S. Environmental Protection Agency has not recommended water quality criteria (WQC) to protect aquatic life from elevated sodium and sulfate concentrations, such as those associated with the coal-processing effluent of Meigs County Mine #31. This discharge, received by a tributary of the Leading Creek Watershed (SE Ohio), had a ...

We identify littoral microcrustacean indicators of acidification in 2 surveys of Canadian Shield lakes conducted 10 years apart. We found a total of 90 cladoceran and copepod species with richness increasing severalfold from acidic to nonacidic lakes. The fauna of the nonacidic lakes differed between the surveys. The 1987 survey ...

Water pollution caused by sulfide oxidation responds to two geochemical processes: a natural one of temporal patterns, and the 'acid mine drainage', an accelerated process derived from the extractive activity. The Odiel River is located in Southwestern Spain; it flows to the south and into the Atlantic Ocean after joining ...

A few physico-chemical and bacteriological parameters on certain locations of the river Torsa was studied. The major characteristics of Torsa river water were high alkalinity, high concentration of free ammonia with respect to albuminoid ammonia and the presence of bacteria of fecal origin. Marked seasonal variations of the parameters were ...

We used rehabilitation experiments involving the stocking of 2 native sportfish, lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieu), in combination with recent fish community surveys, to study the recovery dynamics of fish populations in acid-stressed lakes near Sudbury and Killarney, Ontario, Canada. Population recovery rates differed between the ...

Amoebic gill disease is the main disease affecting the salmonid industry in Tasmania, but no information on the distribution of the causative pathogen, Neoparamoeba pemaquidensis, in the aquatic environment is available. This pilot study aimed to determine temporal and spatial distributions of paramoebae species in the water column, using an ...

We investigated factors causing mercury (Hg) concentrations in northern pike to exceed the consumption advisory level (>500 ng/g) in some inland lakes of Isle Royale National Park. Using Hg-clean techniques, we collected water, zooplankton, macro invertebrates, and fishes in 1998 and 1999 from one advisory lake, Sargent Lake, for analysis ...

The status of fish populations in 3821 lakes in Norway, Sweden and Finland was assessed in 1995-1997. The survey lakes were chosen by stratified random sampling from all (126 482) Fennoscandian lakes > or = 0.04 km2. The water chemistry of the lakes was analyzed and information on fish status ...

We visited 51 lakes in Costa Rica as part of a broad-based survey to document their physical and chemical characteristics and how these relate to the mode of formation and geographical distribution of the lakes. The four oxbow lakes were low in elevation and tended to be turbid, high in ...

This study of the origin and fate of dimethyl sulphide (DMS) in a particular and complex lagoon ecosystem such as that of the Venice lagoon focuses on the temporal evolutions of DMS concentrations in surface water together with those of dimethylsulphoniopropionate (DMSP), carbon disulphide (CS2), nutrients (nitrate, nitrite, ammonium, phosphate, ...

Species such as Dreissena polymorpha sometimes contribute substantially in the transfer of primary to secondary production. During the ontogenetic cycle, the reproductive investment of adult mussels is one of the main parameters that affect recruitment success. We studied how food quality and temperature affect the reproductive investment in term of ...

The Salinas River watershed along the central coast of California, U.S.A., supports rapidly growing urban areas and intensive agricultural operations. The river drains to an estuarine National Wildlife Refuge and a National Marine Sanctuary. The occurrence, spatial patterns, sources and causes of aquatic toxicity in the watershed were investigated by ...

The role of ultraviolet radiation on shallow, high CDOM (colored dissolved organic matter) lakes was investigated during two consecutive summers (1999 and 2000) in replicated mesocosms (rectangular fiberglass tanks). Each tank (volume: 300 L; depth: 40 cm) was covered with a layer (approximately 3 cm) of sediment from lake El ...

Prior to construction of the Aswan High Dam, the annual Nile flood delivered about 7-11 x 10(3) t of biologically available phosphorus (P), at least 7 x 10(3) t of inorganic nitrogen (N), and 110 x 10(3) t of silica (Si) to the Mediterranean coastal waters off Egypt. These nutrients ...

There are two major routes through which fish are exposed to endocrine disruptors (EDs); one route is through water that is a habitat; the other is through aquatic food such as algae and benthos. Few studies on the bioaccumulation of EDs in food have been conducted. Therefore, we evaluated the ...

Water quality monitoring in Europe, especially in transboundary water courses has made steady progress during the last decades through establishment of international commissions. The main activities of these commissions include protection and management of the catchment, sustainable use of the river and establishment of Accident Emergency Warning Systems (AEWS). The ...

The springtime methane (CH4) emission from a small, eutrophied boreal lake was assessed during the winter ice-cover by measurement of gas ebullition and CH4 accumulation in the water column in association with the development of oxygen depletion after ice formation. The winter CH4 production was estimated to result in a ...

The present water quality conditions in the Seto Inland Sea of Japan are described along with an historical background before and after the measures taken to reduce eutrophication. The directive to reduce phosphorus discharge into this area was very effective, reducing the number of red tides from about 300 cases ...

The extent of nonpoint source pollution (NPSP) generated from upstream catchment areas of a reservoir is normally estimated based on a design rainfall. However, rainfall generally varies in different seasons. This seasonal change may significantly influence the estimation of runoff volume and associated NPSP arising within a reservoir watershed. The ...

Long-term trends (i.e., 1985 through 1999; 14 1/2 yrs) of the phytoplankton community in Chesapeake Bay indicated patterns of increasing phytoplankton abundance and biomass associated with mainly diatoms and chlorophytes, and to a lesser degree dinoflagellates. Decreasing trends in productivity rates above the pycnocline were present over a shorter time ...

The three shallow lakes of Mantua (Upper, Middle and Lower) formed by the Mincio River are today classified by Italian water authorities as sensitive areas, after, in the second half of the 20th century, the hydrologic regime of the lakes was heavily modified, and the influence of industrial activities operating ...

Chinook salmon (Oncorhynchus tshawytscha) has been the predominant piscivore in Lakes Michigan, Huron, and Ontario since the 1970s, and therefore accurate quantification of its energy budget is needed for effective management of Great Lakes fisheries. A new approach of evaluating a fish bioenergetics model in the field involves field estimation ...

The Reedy River branch of Lake Greenwood, SC, has repeatedly experienced summertime algal blooms, upsetting the natural system. This lake's shallow depth makes It susceptible to atmospheric influence. A series of experiments were carried out in order to investigate the effect of atmospheric nitrogen deposition into the lake. Nitrogen was ...

Fish are good indicators of the environmental health of rivers and their catchments as well as important conservation targets. Bioindication has to be based on an understanding of the requirement of characteristic species with regard to: (a). The match/mismatch between reproductive strategies and environmental conditions. (b). The niche dimensions of ...

Chironomid larvae were collected and abiotic variables measured at monthly intervals at 21 sampling stations in two lagoons (Guaraná and Patos) and two tributaries (Baía and Ivinheima) of the Upper Paraná River floodplain. The genera Procladius, Chironomus, Goeldichironomus, and Polypedilum were dominant in the lagoons and in the Baía River, ...

Safety is the prime consideration and food manufacturers must ensure that products pose a minimum hazard to the consumer. The required safety must be achieved by preventing growth of pathogens during production and by reducing the remaining contamination to the lowest possible level. Dry and semi-dry fermented sausages are generally ...

Bacterial community composition was monitored in four shallow eutrophic lakes during one year using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified prokaryotic rDNA genes. Of the four lakes investigated, two were of the clearwater type and had dense stands of submerged macrophytes while two others were of the turbid type ...

Cyanobacterial hepatotoxin accumulation in mussels (Mytilus edulis, Dreissena polymorpha), clam (Macoma balthica), and flounder (Platichthys flesus) tissues was measured. Flounder were caught with gillnets from the western Gulf of Finland on 21 August 1999, 25 July 2000, and 25 August 2000. Blue mussels were collected from: (1) a steel cage ...

Megalodicopia hians Oka is a solitary ascidian belonging to the family Octacnemidae inhabiting the bathyal /abyssal zone as well as other octacnemid ascidians. The phylogenetic relationship of octacnemids is open to argument because of its extraordinary morphological features due to habitat adaptation, e.g., a pharynx lacking ciliated stigmata. Aggregations of ...

In the current study, the hepatotoxic peptide microcystins, were measured in the zooplankton community of Jacarepaguá Lagoon during a 6-month period. Concurrent phytoplankton and seston samples were obtained. Microcystins were measured in seston and phytoplankton by High Performance Liquid Chromatography (HPLC), and in zooplankton by an Enzyme-Linked Immunosorbant Assay (ELISA). ...

The present estimates of ice drift in the Arctic include utilization of satellite imagery data (special sensor microwave/imager) and a reconstruction of air pressure for the period 1899-1998. A significant part of the sea ice in the Arctic Ocean has its origin in the Kara Sea and melts in the ...

Methane-oxidizing bacteria (methanotrophs) containing soluble methane monooxygenase (sMMO) are of interest in natural environments due to the high co-metabolic activity of this enzyme with contaminants such as trichloroethylene. We have analysed sMMO-containing methanotrophs in sediment from a freshwater lake. Environmental clone banks for a gene encoding a diagnostic sMMO subunit ...

Suspended fine particles (seston) are an important component of energy and nutrient cycling in streams, but they can also be pollutants. We examined seston dynamics and filter-feeding macroinvertebrate communities in sites representing headwaters to large rivers in the Kansas River drainage, northeastern KS. Seston samples were collected at least seasonally ...

Two kinds of stilbene-type fluorescent whitening agents (i.e., DSBP and DAS1), minor components of laundry detergents, were analyzed in surface waters of Tokyo Bay and adjacent rivers and in sewage effluents to examine their usefulness as molecular markers in the marine environment. Sensitive determination using HPLC (high performance liquid chromatography) ...

The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning ...

Physical processes such as advection, dispersion, and air-water gas exchange play important roles in determining the movement and change in concentration of contaminants discharged into rivers. In the following, we report results from a large-scale SF6 tracer release experiment conducted in the tidal Hudson Riverto examine longitudinal dispersion and net ...

In response to the recent focus by the U.S. Environmental Protection Agency on bioassessment of lakes, a multimetric index was developed for New Jersey lakes and reservoirs using benthic macroinvertebrates. Benthic samples were collected from reference and impaired lakes with muck and intermediate sediments in central and northern New Jersey ...

In Antarctic lakes, organisms are confronted by continuous low temperatures as well as a poor light climate and nutrient limitation. Such extreme environments support truncated food webs with no fish, few metazoans and a dominance of microbial plankton. The key to success lies in entering the short Antarctic summer with ...

The Susquehanna River watershed has a large drainage area (71200 km(2)) containing heavy agricultural land usage. The river provides approximately half the total freshwater input to the Chesapeake Bay. Water samples were collected at Conowingo Dam near the mouth of the river every 9 days from February 1997 through March ...

Nutrient loads to large, shallow Lake Balaton have been reduced by 45-50% since mid-1980s. While a delayed, but still surprisingly fast recovery was observed in the hypertrophic western areas of the lake, eutrophication followed sewage diversion from the mesotrophic northern basins. We assessed factors that could lead to this unusual ...

International regulation of organotin compounds for use in antifouling paints has led to the development and increased use of replacement compounds, notably the s-triazine herbicide Irgarol 1051. Little is known about the distribution of Irgarol 1051 in tropical waters. Nor has the potential impact of this triazine upon photosynthesis of ...

We investigated the validity and sensitivity of assessments of the induction of atrazine tolerance in freshwater outdoor mesocosmic phytoplankton communities, using the in vivo fluorescence of chlorophyll a as an endpoint, for monitoring ecotoxicology and for risk assessment programs applied to phytoplankton contaminated by photosystem II herbicides. Atrazine inhibits the ...

This work was conducted to analyse pressing and competing demands of water in Northeast Sicily, Italy. In this area, looking at the Ionian Sea, freshwaters and coastal seawaters have been studied on the quality and on the transport processes of pollutants. Attention has been focused on chemical and microbial parameters ...