Temporal trends of polychlorinated biphenyls (PCBs) in Lake Ontario fish and invertebrates

1999 ◽  
Vol 7 (4) ◽  
pp. 203-223 ◽  
Author(s):  
E Bentzen ◽  
D Mackay ◽  
B E Hickie ◽  
D RS Lean
Keyword(s):  
Food Web ◽  
Lake Trout ◽  
Temporal Trends ◽  
Lake Ontario ◽  
Fish Food ◽  
International Joint Commission ◽  
Analytical Protocol ◽  
Fish Lipid ◽  
Key Species ◽  
Aquatic Food

A comprehensive review is presented of changes of PCB concentrations in aquatic biota collected from Lake Ontario between 1977 and 1993, with emphasis on data for lake trout. Results of three major lake trout surveys from Canadian and United States agencies indicate lake trout PCBs have declined from the early 1980s, but changes in recent years are masked by interannual variability. These results also apply to other biota in the aquatic food web. PCB concentrations were consistent among the surveys after consideration of fish lipid content, age or size and analytical protocol. Variability of 20 to 30% in annual average estimates is attributed to both analytical and in situ sources. Current levels of PCBs in many salmonids exceed PCB consumption and wildlife protection advisories. The average half-life for PCBs in Lake Ontario biota is about 12 years and it will take three to four times that to reach the International Joint Commission target of 100 ng/g (ww) for protection of wildlife. It is essential that the design of monitoring programs ensures consistent, coordinated sampling and analysis. A monitoring strategy of annual sampling of key species supplemented with periodic intensive sampling of the entire food web (e.g., every 5 years) is suggested as more effective than current practices. There is a frequently neglected need for fuller interpretation of contaminant dynamics based on complementary research on the nature of the changing biotic and abiotic environments in a complex aquatic ecosystem like Lake Ontario. Key words: Lake Ontario, PCBs, fish, food webs, monitoring data, bioaccumulation.

Dechlorane plus monoadducts in a lake ontario (Canada) food web and biotransformation by lake trout (Salvelinus namaycush)liver microsomes

2013 ◽  
Vol 32 (6) ◽  
pp. 1376-1381 ◽  
Author(s):  
Gregg T. Tomy ◽  
Ed Sverko ◽  
Vince Palace ◽  
Bruno Rosenberg ◽  
Robert McCrindle ◽  
...  
Keyword(s):  
Food Web ◽  
Lake Trout ◽  
Liver Microsomes ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Dechlorane Plus

Spatial and temporal trends of mercury in the aquatic food web of the lower Penobscot River, Maine, USA, affected by a chlor-alkali plant

2019 ◽  
Vol 649 ◽  
pp. 770-791 ◽  
Author(s):  
A. Dianne Kopec ◽  
Karen A. Kidd ◽  
Nicholas S. Fisher ◽  
Marcia Bowen ◽  
Corey Francis ◽  
...  
Keyword(s):  
Food Web ◽  
Temporal Trends ◽  
Aquatic Food Web ◽  
Penobscot River ◽  
Aquatic Food ◽  
Spatial And Temporal Trends

Present Status and Temporal Trends of Organochlorine Contaminants in Young-of-the-Year Spottail Shiner (Notropis hudsonius) from Lake Ontario

1991 ◽  
Vol 48 (8) ◽  
pp. 1568-1573 ◽  
Author(s):  
K. Suns ◽  
G. Hitchin ◽  
E. Adamek
Keyword(s):  
Present Status ◽  
Temporal Trends ◽  
Lake Ontario ◽  
Forage Fish ◽  
Aquatic Life ◽  
International Joint Commission ◽  
Organochlorine Contaminants ◽  
Residue Levels ◽  
Young Of The Year ◽  
Collection Sites

Contaminant residue data from Ontario nearshore collections of young-of-the-year spottail shiner (Notropis hudsonius) were used to assess present status and temporal trends of bioavailable organochlorine contaminants in Lake Ontario. PCB residues in spottail shiners were in excess of the International Joint Commission Aquatic Life Guideline at 11 of the 14 sites sampled in 1987; mirex residues exceeded the Guideline at 7 of the 14 sites sampled. PCB and total DDT residues in the recent shiner collections were significantly (p < 0.01) lower relative to residue levels in collections in the 1970's. However, residue declines have slowed during the 1980's. Thus, PCB residues in spottail shiners declined by 69% over a 5-yr interval (1975–80) whereas residues declined only by 17% at the same sites during the following 7-yr interval (1980–87). Residues of hexachlorobenzene, heptachlor, aldrin, total hexachlorocyclohexane, octachlorostyrene, total chlordane, and toxaphene were generally near their detection limits in all shiner collections. A Forage Fish Contaminant Index was established for the purpose of ranking the collection sites in relative order of contamination to assess the need for point-source investigations.

Occurrence and trophic transfer of nanoparticulate Ag and Ti in the natural aquatic food web of Taihu Lake, China

2019 ◽  
Vol 6 (11) ◽  
pp. 3431-3441 ◽  
Author(s):  
Bowen Xiao ◽  
Yinqing Zhang ◽  
Xiaolei Wang ◽  
Meng Chen ◽  
Binbin Sun ◽  
...  
Keyword(s):  
Food Web ◽  
Taihu Lake ◽  
Trophic Transfer ◽  
Aquatic Food Web ◽  
Fish Food ◽  
Aquatic Food

Nanoparticulate Ti was biodiluted while nanoparticulate Ag was biomagnified in the fish food web in Taihu Lake, China.

Prey fish exploitation, salmonine production, and pelagic food web efficiency in Lake Ontario

1998 ◽  
Vol 55 (2) ◽  
pp. 318-327 ◽  
Author(s):  
Peter S Rand ◽  
Donald J Stewart
Keyword(s):  
Food Web ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Prey Fish ◽  
Rainbow Smelt ◽  
Time Model

Estimates of production and predation rates from bioenergetic models of chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and lake trout (Salvelinus namaycush) suggest a long-term decline in their gross conversion efficiency (gross production/prey consumption) and the gross production to biomass ratio in Lake Ontario during 1978-1994. The former pattern was caused primarily by a declining trend in adult alewife (Alosa pseudoharengus) energy density during 1978-1985; the latter pattern resulted from reductions in growth rates (coho salmon) and a buildup of the older age-classes in the population (lake trout) over time. Model results suggest that over 100 and 25% of the annual production of adult alewife and rainbow smelt (Osmerus mordax), respectively, was consumed by salmonines during 1990 in Lake Ontario; hence, we claim that recent observations of reduced salmonine growth in Lake Ontario may be a result of prey limitation. Energy transfer from primary production to salmonines appeared to be more efficient in Lake Ontario than in Lake Michigan, probably due to higher stocking levels per unit area and higher densities of preferred prey fish in Lake Ontario. Through separate analyses, we arrived at conflicting conclusions concerning the sustainability of the food web configuration in Lake Ontario during 1990.

Recent Changes in the Aquatic Food Web of Eastern Lake Ontario

1987 ◽  
Vol 44 (S2) ◽  
pp. s37-s52 ◽  
Author(s):  
W. J. Christie ◽  
K. A. Scott ◽  
P. G. Sly ◽  
R. H. Strus
Keyword(s):  
Prey Species ◽  
Lake Trout ◽  
Prey Availability ◽  
Lake Ontario ◽  
Size Composition ◽  
Osmerus Mordax ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Aquatic Food ◽  
Representative Samples

During the past 10 yr there have been dramatic increases in piscivorous populations of walleye (Stizostedion vitreum) in the Bay of Quinte and of planted lake trout (Salvelinus namaycush) and double-crested cormorants (Phalacrocorax auritus) in the Kingston basin of Lake Ontario. This paper documents changes in the prey stocks shared by these piscivores, including reduction in size and abundance of the slimy sculpin (Cottus cognatus) with subsequent stock equilibration and unabated reduction in the size and abundance of rainbow smelt (Osmerus mordax), both owing to predation pressure from the lake trout. The third primary prey species, alewife (Alosa pseudoharengus), has not yet suffered severely from the depredations of the piscivores. Symptoms of the effects are discernible, however, and the implications of a possible collapse are discussed. Lake trout survival and growth have not yet been affected by the changes in prey availability, but their diet has shifted both in response to their own expanded size composition and relative abundance of the three prey species. Increased utilization of alewife makes the hunting of the trout more pelagic. Problems of obtaining representative samples of the prey are discussed.

BROMINATED AND CHLORINATED FLAME RETARDANTS IN LAKE ONTARIO, CANADA, LAKE TROUT (SALVELINUS NAMAYCUSH) BETWEEN 1979 AND 2004 AND POSSIBLE INFLUENCES OF FOOD-WEB CHANGES

2009 ◽  
Vol 28 (5) ◽  
pp. 910 ◽  
Author(s):  
Nargis Ismail ◽  
Sarah B. Gewurtz ◽  
Kerri Pleskach ◽  
D. Michael Whittle ◽  
Paul A. Helm ◽  
...  
Keyword(s):  
Food Web ◽  
Flame Retardants ◽  
Lake Trout ◽  
Lake Ontario ◽  
Salvelinus Namaycush

Dynamics of bacteria–substrate stable isotope separation: dependence on substrate availability and implications for aquatic food web studies

2008 ◽  
Vol 65 (9) ◽  
pp. 1983-1990 ◽  
Author(s):  
Daryl J. McGoldrick ◽  
David R. Barton ◽  
Michael Power ◽  
Ryan W. Scott ◽  
Barbara J. Butler
Keyword(s):  
Food Web ◽  
Exponential Growth Phase ◽  
Substrate Availability ◽  
Aquatic Food Web ◽  
Fish Food ◽  
Web Studies ◽  
Isotopic Signatures ◽  
C And N ◽  
Isotopic Separation ◽  
Aquatic Food

Heterotrophic bacteria growing without substrate limitation discriminate against the heavier stable isotopes of C and N, which is reflected in the isotopic signatures of consumers of bacteria. We measured bacteria and substrate isotopic separation (C and N) during glucose and ammonium uptake by three strains of bacteria ( Pseudomonas putida , Bacillus megaterium , and Enterobacter aerogenes ) grown in batch culture at 4 and 30 °C. Isotopic separation between bacteria and substrate was dependent on substrate availability. Higher discrimination against the heavier isotopes, and therefore more depleted δ13C and δ15N values of bacterial biomass, were observed during the exponential growth phase when the nutrient supply was in excess of the demand. We also compared the isotopic ratios of Chironomus tentans grown on aged macrophyte detritus and commercial fish food. Isotopic signatures of Chironomus larvae grown on fish food were within the ranges typical of one trophic step, whereas larvae grown on detritus were strongly depleted in13C, suggesting assimilation of bacteria that had grown on the C-rich detritus. Our results are consistent with the very few other studies of bacterial fractionation of nonlimiting nutrients and may also explain the frequent observation of unexpectedly depleted isotopic signatures in aquatic food web studies.

Alternative Ecological Pathways in the Eastern Lake Ontario Food Web—Round Goby in the Diet of Lake Trout

2006 ◽  
Vol 32 (2) ◽  
pp. 395-400 ◽  
Author(s):  
Jason P. Dietrich ◽  
Bruce J. Morrison ◽  
James A. Hoyle
Keyword(s):  
Food Web ◽  
Lake Trout ◽  
Round Goby ◽  
Lake Ontario
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