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

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

Evidence of successful river spawning by lake trout (Salvelinus namaycush) in the Lower Niagara River, Lake Ontario

2021 ◽  
Author(s):  
Alexander Gatch ◽  
Dimitry Gorsky ◽  
Zy Biesinger ◽  
Eric Bruestle ◽  
Kelley Lee ◽  
...  
Keyword(s):  
Lake Trout ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Niagara River

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

2010 ◽  
Vol 408 (7) ◽  
pp. 1725-1730 ◽  
Author(s):  
Charles P. Madenjian ◽  
Michael J. Keir ◽  
D. Michael Whittle ◽  
George E. Noguchi
Keyword(s):  
Sexual Difference ◽  
Lake Trout ◽  
Lake Ontario ◽  
Salvelinus Namaycush

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.

Bioenergetics and PCB, DDE, and Mercury Dynamics in Lake Ontario Lake Trout (Salvelinus namaycush): A Model based on Surveillance Data

1992 ◽  
Vol 49 (6) ◽  
pp. 1086-1096 ◽  
Author(s):  
U. Borgmann ◽  
D. M. Whittle
Keyword(s):  
Gastrointestinal Tract ◽  
Lake Trout ◽  
Prey Selection ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Whole Body ◽  
Alosa Pseudoharengus ◽  
Assimilation Rate ◽  
Feeding Rates ◽  
Dynamics Model

Lake trout (Salvelinus namaycush) ingestion rates in a bioenergetics and contaminant dynamics model were estimated directly from contaminant concentrations in lake trout and their prey, rather than from the sum of growth and predicted metabolism. Elimination rates for PCB and DDE, but not for mercury, were dependent on either body mass or lipid content. Concentrations in lake trout responded rapidly to changes in concentration of their prey. This was due primarily to growth dilution and not contaminant elimination, especially for DDE and PCB. Changes in lipid concentrations, therefore, have only minor effects on final concentrations in lake trout, and it is not appropriate to lipid normalize PCB or DDE concentrations when examining trends in whole-body concentrations for this species. Concentrations of PCBs and lipids have declined in lake trout from 1977 to 1988. The drop in PCB concentrations is probably not caused primarily by the lowered lipid concentrations but is the result of either a reduction in feeding rates and improved growth efficiencies, a reduction in PCB concentrations in alewife (Alosa pseudoharengus), or an undocumented change in prey selection. Models based on chemical kinetics across the gastrointestinal tract are more consistent with observed data than models based on a constant contaminant assimilation rate and direct excretion.

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.

Assessment of Sea Lamprey (Petromyzon marinus) Predation by Recovery of Dead Lake Trout (Salvelinus namaycush) from Lake Ontario, 1982–85

1988 ◽  
Vol 45 (8) ◽  
pp. 1406-1410 ◽  
Author(s):  
Roger A. Bergstedt ◽  
Clifford P. Schneider
Keyword(s):  
Lake Trout ◽  
Stock Assessment ◽  
Petromyzon Marinus ◽  
Lake Ontario ◽  
Sea Lamprey ◽  
Salvelinus Namaycush ◽  
Fish Stock ◽  
Annual Fish ◽  
Dead Fish ◽  
Fish Stock Assessment

During 1982–85, 89 dead fake trout (Salvelinus namaycush) were recovered with bottom trawls in U.S. waters of Lake Ontario: 28 incidentally during four annual fish-stock assessment surveys and 61 during fall surveys for dead fish. During the assessment surveys, no dead lake trout were recovered in April–June, one was recovered in August, and 27 were recovered in October or November, implying that most mortality from causes other than fishing occurred in the fall. The estimated numbers of dead lake trout between the 30- and 100-m depth contours in U.S. waters ranged from 16 000 (0.08 carcass/ha) in 1983 to 94 000 (0.46 carcass/ha) in 1982. Of 76 carcasses fresh enough to enable recognition of sea lamprey (Petromyzon marinus) wounds, 75 bore fresh wounds. Assuming that sea lamprey wounding rates on dead fish were the same as on live ones of the same length range (430–740 mm), the probability of 75 of the 76 dead lake trout bearing sea lamprey wounds was 3.5 × 10−63 if death was independent of sea lamprey attack, thus strongly implicating sea lampreys as the primary cause of death of fish in the sample. The recovery of only one unwounded dead lake trout also suggested that natural mortality from causes other than sea lamprey attacks is negligible.

A stable isotope evaluation of the structure and spatial heterogeneity of a Lake Superior food web

2000 ◽  
Vol 57 (7) ◽  
pp. 1395-1403 ◽  
Author(s):  
Chris J Harvey ◽  
James F Kitchell
Keyword(s):  
Stable Isotope ◽  
Spatial Heterogeneity ◽  
Food Web ◽  
Lake Trout ◽  
Trophic Position ◽  
Lake Superior ◽  
Salvelinus Namaycush ◽  
Trophic Relationships ◽  
Rainbow Smelt ◽  
Western Lake

We used stable isotope analysis to derive trophic relationships and movement patterns for components of the western Lake Superior food web. Trophic linkages implied by previous gut content studies were only marginally supported by stable isotope data. Siscowet lake trout (Salvelinus namaycush siscowet) were the top predators, and trophic overlap between siscowet and lean lake trout (Salvelinus namaycush) was low. Exotic Pacific salmon (Oncorhynchus spp.) occupied a lower trophic position than native piscivores because the latter relied more on coregonids. To evaluate spatial heterogeneity of the food web, we assumed that the adjacent cities of Duluth and Superior (DS) were a point source of 15N, and we measured isotopes of organisms close to and far from DS. Slimy sculpin (Cottus cognatus) were enriched in the DS area relative to other sites, implying that they are relatively sedentary. Rainbow smelt (Osmerus mordax) showed no differences at any sites, implying high vagility. Other organisms showed differences that could not be attributed to DS, implying that other mechanisms, such as trophic ontogeny, were influencing their isotopic signatures.

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