Historical relationships between organochlorines and stable isotopes in Lake Trout from Lake Ontario
- Great Lakes Lab. for Fisheries and Aquatic Sciences, Burlington, Ontario (Canada)
- McGill Univ., Montreal, Quebec (Canada)
Large fluctuation in the organochlorine contamination reported in Lake Ontario lake trout has been attributed to temporal changes in diet composition. As part of an annual monitoring program a tissue archive of Great Lakes fish has been maintained since the late 1970`s. Archive samples of four year old lake trout from the eastern basin of Lake Ontario collected between 1978 and 1 992 were analyzed for organochlorines, including coplanar PCBs and dioxin/furan isomers, and stable isotope ratios of carbon and nitrogen. The isotope signature of nitrogen remained relatively constant over the study period while the isotope signature of carbon declined significantly since the mid 1980`s. Collections of net plankton, mysids, amphipods, forage fish (sculpin, alewife, smelt) and lake trout from 1992 showed a distinctive increase in the nitrogen signature with increasing trophic level. There was a very strong correlation between PCB, DDE and mirex concentrations and stable isotope signatures of nitrogen. A difference in carbon signatures in the forage fish species is consistent with a diet change (based on gut contents) and a carbon signature shift observed in lake trout. However, the carbon signatures in the foodchain are not correlated with the organochlorine contaminant levels. Changes in the carbon signature at the lower end of the foodchain in response to reduced nutrient availability could also result in a similar shift at the higher trophic levels.
- OSTI ID:
- 49516
- Report Number(s):
- CONF-9410273-; TRN: IM9523%%339
- Resource Relation:
- Conference: 15. annual meeting of the Society of Environmental Toxicology and Chemistry (SETAC), Denver, CO (United States), 30 Oct - 3 Nov 1994; Other Information: PBD: 1994; Related Information: Is Part Of Society of Environmental Toxicology and Chemistry 15th annual meeting: Abstract book. Ecological risk: Science, policy, law, and perception; PB: 286 p.
- Country of Publication:
- United States
- Language:
- English
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