Title: Species Sensitivity to Copper: Acute Toxicity to Channel Catfish and Sunshine Bass Author
Submitted to: Journal of Applied Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 26, 2005
Publication Date: May 1, 2006
Citation: Straus, D.L. 2006. Species sensitivity to copper: acute toxicity to channel catfish and sunshine bass. Journal of Applied Aquaculture. 18(1):88-99. Interpretive Summary: Copper sulfate is a widely used chemical in aquaculture where it is used to kill algae and fungus or parasites on fish. Sunshine bass (hybrid striped bass) production is a rapidly expanding industry, but there is no data on the toxicity of this chemical. Tests were run to find out how much copper sulfate is acutely toxic to channel catfish and sunshine bass juveniles (10 and 12 g, respectively) over a 96 hour period. Copper is toxic according to the alkalinity and hardness of the water (in lower alkalinity waters it is more toxic); the alkalinity and hardness was 224 and 110 mgL-1, respectively. We found the amount that would be toxic to the fish, but we also found that the copper sulfate was more toxic to sunshine bass; the difference was statistically significant. This is the first research to determine the acute toxicity of copper to sunshine bass. This information is important to fish farmers and aquaculture extension agents, and will save the farmers money from fish losses.
Technical Abstract: Channel catfish, Ictalurus punctatus (Rafinesque, 1818), and sunshine bass, female white bass Morone chrysops (Rafinesque, 1820) x male striped bass M. saxatilis (Walbaum, 1792), juveniles (10 and 12 g, respectively) were exposed to copper sulfate in a series of static toxicity tests to observe species sensitivity. The water used in this study was 18.9°C filtered well water with initial pH of 8.71, and total alkalinity and total hardness of 224 and 110 mgL-1, respectively. Estimates of mean 96-hr median lethal concentration (LC50) values were 1.75 mgL-1 Cu (6.89 mgL-1 CuSO4) for channel catfish and 0.85 mgL-1 Cu (3.35 mgL-1 CuSO4) for sunshine bass. These values differed significantly. This study demonstrates that sunshine bass juveniles are less tolerant of CuSO4 than channel catfish fingerlings when exposed concurrently in waters from the same source.