Comparison of the effects of sublethal concentrations of biofoulants, copper pyrithione and zinc pyrithione on a marine mysid - A multigenerational study

Abstract

To determine the effect of copper pyrithione (CuPT) and zinc pyrithione (ZnPT), a set of acute (96 h–LC50) and chronic endpoints was studied in the marine mysid, Neomysis awatschensis. Based on the 1/10 NOECs and NOEC values calculated from 96 h–toxicity test, survival and growth, intermolt duration, feeding, and the number of newborn juveniles were measured by evaluating enzymatic activity of detoxification parameter glutathione S–transferase (GST) and cholinergic biomarker acetylcholinesterase (AChE) in the marine mysid exposed to 96 h–NOECs of CuPT and ZnPT for four weeks across three generations. Dose–dependent decreases in survival rate monitored for four weeks were observed with age–specific sensitivity in response to the 96 h–NOECs of both antifoulants. Higher growth retardation was observed with an increase in intermolt duration and inhibition of the feeding rate in CuPT–exposed mysid compared to ZnPT–exposed mysid across generations. The numbers of newborn juveniles significantly decreased at the third generation by exposure to the 96 h–NOECs of both antifoulants. GST activity was significantly inhibited in response to 96 h–NOECs of both antifoulants, whereas AChE activity was only reduced by the 96 h–NOECs of CuPT at the third generation. These results indicate that CuPT has a higher toxicity than ZnPT and even sublethal levels of CuPT and ZnPT would have detrimental effects on the maintenance of the mysid population. Finally, consistent exposure to environmentally relevant concentrations of CuPT and ZnPT can induce intergenerational toxicity in mysid.