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(75-08) Temperature induced metal accumulation and stress responses in fish from Canadian arctic lakes. Koeck, Guenter*,1, Doblander, Christine1, Berger, Burkhard2, Niederstaetter, Harald2, Bright, Douglas3, Muir, Derek4, Reist, James5, Babaluk, John5, Kalra, Yash6, 1 Institute of Zoology and Limnology, University of Innsbruck, Innsbruck, Austria2 Institute of Legal Medicine, University of Innsbruck, Innsbruck, Austria3 Royal Roads University, Victoria, BC, Canada4 Environment Canada, Burlington, ON, Canada5 Department of Fisheries and Oceans, Winnipeg, Canada6 Canadian Forestry Service, Edmonton, Canada ABSTRACT- Here we report that global warming may endanger fish populations in arctic lakes by leading to an increase in metal accumulation and stress. This multi-year study of small sensitive lake ecosystems in the Canadian Arctic Archipelago, is aimed to explain the interactions between short and longer term variation in lake water temperature, the bioaccumulation of metals, biochemical stress indicators and energy status in land-locked populations of Arctic char (Salvelinus alpinus). Comparison of metal levels (e.g. cadmium, zinc) and biochemical stress indicators (e.g. glutathion, glutathion disulfide) in the blood or various tissues of char collected from small lakes near Resolute, Nunavut, during the summers of 1997, 1998, 1999 and 2000 revealed marked seasonal and inter-annual trends in the turnover of metals, as well as stress responses in the liver. Similar to char from Austrian high mountain lakes, concentrations of Cd and Zn in the liver of char from Resolute Lake exhibited a clear seasonal change during summer, and were significantly higher at the end of the ice free period. Atypically warm temperatures in the Canadian Arctic in 1998, likely to be a consequence of the very strong 1997/1998 El Niño event, led to an early break-up of ice and much higher than normal summer-time lake water temperatures. These high water temperatures were reflected by a clear physiological response of the fish studied. In 1998, both the concentration of metals in fish liver and the level of stress were significantly higher when compared to the colder years 1997, 1999 and 2000. Concentrations of Cd in the liver were positively correlated with the mean summer air temperatures at the sampling site. Rising water temperatures lead to increased metabolic rates and thus pumping of higher volumes of water across the gills which in turn resulted in increased uptake of dissolved metals from the water. Predictive relationships between lake temperature and metal uptake were similar for high arctic lakes and previously studied Austrian high mountain lakes, thus confirming water temperature to be the driving force of metal accumulation in fish from these sensitive ecosystems. The study illustrates that fish from high latitude and high altitude lakes could be used as sensitive indicators of the interactive effects of pollution and global climate change. Key words: climate change, Arctic, metal contamination, stress |
