in this study, eutrophication was investigated in lake ontario to identify the interactions among effective drivers. the complexity of such phenomenon was modeled using a system dynamics approach based on a consideration of constant and variable stoichiometric ratios. the system dynamics approach is a powerful tool for developing object-oriented models to simulate complex phenomena that involve...

High-volume air samples were collected during research cruises of Lake Superior in August 1996 and May 1997 and of Lake Ontario (North America) in July and September 1998 and June 2000 and analyzed for polychlorinated naphthalenes (PCNs). Levels of tetra- to octachloronaphthalene (sigmaPCN) varied spatially, with mean values (+/-SD) of 1.78 +/- 0.74 and 1.46 +/- 1.07 pg m(-3) for Lake Superior ...

Diets containing coho salmon (Oncorhynchus kisutch Walbaum) from the Pacific Ocean or from Lakes Erie, Michigan, and Ontario [containing a gradation from low to high of halogenated aromatic hydrocarbons, (HAHs)] were fed to C57B1/6 and DBA/2 mice. Following a 4-month dietary exposure to Lake Ontario salmon, both strains of mice demonstrated hepatomegaly. The ethoxyresorufin-O-deethylase (ERR) e...

O. El-Sherif, R. Z. Stodilka, N. A. Pack, E. V. Dibella, J. A. White, R. T. Thompson, and F. S. Prato Imaging, Lawson Health Research Institute, London, Ontario, Canada, Medical Biophysics, University of Western Ontario, London, Ontario, Canada, Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States, Radiology, Utah Center for Advanced Imaging Research, Salt Lake ...

The identification, persistence, accumulation and trophic transfer of 25 polybrominated diphenyl ether (PBDE) congeners, 23 non-PBDE halogenated flame retardants (NPHFRs), 4 polybrominated-diphenoxybenzenes (PB-DiPhOBzs) and 6 methoxylated (MeO-) PB-DiPhOBzs were investigated in predator and prey fish collected in 2010 from sites in the North American Great Lakes of Ontario (n = 26) and Erie (n...

Crayfish (Orconectes spp.) and sculpins (Cottus spp.) were collected at eight lake trout spawning reefs in Lake Ontario to assess abundance and potential to consume lake trout eggs. Abundance of crayfish ranged from a high of 9.5/m2 in eastern Lake Ontario to 0/m2 in western Lake Ontario where the absence or near absence at four reefs sampled was attributed to cold water upwelling. Sculpin abun...

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 concentrations of OH-PCB congeners, pentachlorophenol (PCP...

Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow ...

1. In North America, the invasive predatory cladoceran Cercopagis pengoi was first detected in Lake Ontario. We explored the impact of Cercopagis on the lower food web of Lake Ontario through assessments of historical and seasonal abundance of the crustacean zooplankton, by conducting feeding experiments on the dominant prey of the invader, and by estimating its food requirements. 2. Between 19...

The extent of bioaccumulation of the syn- and anti-isomers of Dechlorane Plus (DP) is assessed in archived food web samples from Lake Winnipeg and Lake Ontario. Concentrations of the isomers were determined using purified analytical solutions of individual isomers as opposed to the technical mixture. The syn-isomer was consistently detected in all samples from both lakes; the anti-isomer was de...