| Abstract/Description or Keywords |
We combine information on the influence of temperature on the thermal physiology, growth, and survival of sockeye salmon (Oncorhynchus nerka) with projections of temperature change associated with a doubling of atmospheric CO2 concentrations (over pre-industrial levels) to determine the effect of global warming on two freshwater life history stages (lake residence of juveniles, and spawning by adults) of sockeye salmon from Adams River, British Columbia. Air temperatures are expected to increase by approximately 4.0ﾰ and 2.5ﾰ C in the summer and winter respectively in the vicinity of the Adams River. Shuswap Lake is used as a rearing area by the juvenile sockeye salmon and global warming will probably change the production characteristics of lake towards a more oligotrophic system. This will cause a reduction in the abundance and availability of food for the juvenile sockeye salmon, and hence a decrease in their freshwater growth, and freshwater and marine survival. However, the increased temperature encountered by adults on the spawning grounds of the Adams River is unlikely to result in higher rates of prespawning mortality. It is anticipated that the net effect of global warming over all freshwater life history stages will be a reduction in the freshwater production of Adams River sockeye salmon. |
