The Effectiveness of Flow‐Through or Static Copper Sulfate Treatments on the Survival of Golden Shiners and Fathead Minnows Infected with Flavobacterium columnare

Abstract

AbstractFour studies were conducted to compare the effects of copper sulfate (CuSO4), when delivered in either a flow‐through or a static system, on the survival of Golden Shiners Notemigonus crysoleucas and Fathead Minnows Pimephales promelas infected with Flavobacterium columnare. The treatment regimens were administered to fish in well water and were based on the recommended treatment rate (1% of alkalinity). Golden Shiners (experiments 1 and 3) and Fathead Minnows (experiments 2 and 4) were treated separately. In experiments 1 and 2, the treatment rate was 2.0 mg/L CuSO4 applied to a flow‐through system daily for five consecutive days; control fish were untreated. Study durations were 7 d with the majority of the mortalities occurring in the first 5 d. Survival rates in the flow‐through system were 77% and 69% for CuSO4‐treated Golden Shiners and Fathead Minnows, respectively. Survival in both species was significantly different from that in their untreated control fish, which was 33% for Golden Shiners and 41% for Fathead Minnows. Static applications of CuSO4 were investigated in experiments 3 and 4. Treatment doses were 0, 0.5, 1, 2, and 4 mg/L (approximately 0.0, 0.25, 0.5, 1, and 2 times the recommended rate). Survival of Fathead Minnows in this experiment was 10, 28, 52, 47, and 35% in the 0, 0.5, 1, 2, and 4 mg/L CuSO4 treatments, respectively. The corresponding survival of Golden Shiners was 49, 50, 65, 75, and 60% in the 0, 0.5, 1, 2, and 4 mg/L CuSO4 treatments, respectively.