Reproductive Success, Early Life Stage Development, and Survival of Westslope Cutthroat Trout (Oncorhynchus clarki lewisi) Exposed to Elevated Selenium in an Area of Active Coal Mining

The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewis,) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 microg/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability; however, in the present study, eggs with Se concentrations > 86.3 microg/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations > 46.8 and 20.6 microg/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish.