Repeated copper sulfate treatments have no effect on growth and survival of juvenile Walleye

Objective An experiment was conducted to evaluate the effects of repeated copper sulfate (CuSO 4 ) treatments on the growth and survival of juvenile Walleye Sander vitreus . Methods Culture tanks were treated with 0 or 0.76 mg/L CuSO 4 every other day for five exposures, then were not treated for 14 consecutive days; this regimen was repeated for a total of 10 exposures over the course of 50 days. Copper sulfate treatments had a half‐life of about 60 min. The study was conducted in flow‐through well water at ≈1.5 L/m and 23.8°C. Result The resulting survival data for CuSO 4 treated and nontreated fish was 96% and 85% survival, respectively, and not statically different. There was no difference in weight, with treated weighing 25.3 g compared to 25.2 g for nontreated control fish. Both groups had weight increases of over 400% during the study. Neither group differed in length, with treated fish reaching a mean length of 14.6 cm and nontreated reaching a mean length of 14.5 cm. Conclusion The results indicate that repeated CuSO 4 treatments had no effect on Walleye growth or survival.