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

ObjectiveAn experiment was conducted to evaluate the effects of repeated copper sulfate (CuSO4) treatments on the growth and survival of juvenile Walleye Sander vitreus.MethodsCulture tanks were treated with 0 or 0.76 mg/L CuSO4 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.ResultThe resulting survival data for CuSO4 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.ConclusionThe results indicate that repeated CuSO4 treatments had no effect on Walleye growth or survival.