CALIFORNIA ENVIRONMENTAL PROTECTION AGENCY

Abstract

In the summer and fall of 2006, the Department of Pesticide Regulation (DPR) sampled water and sediment from 23 marinas to assess the geographical scope and severity of pollution stemming from the use of antifouling paint (AFP) pesticides in California. Copper, zinc, Irgarol, M1 (the primary breakdown product of Irgarol), and aquatic toxicity were selected as potential indicators of AFP pollution. The highest dissolved copper concentrations were observed in larger salt water marinas along California’s Central and South Coast, the lowest were seen in freshwater lake marinas. Copper and zinc concentrations were almost always higher in the marinas than in the adjacent local reference sites, indicating that significant sources of metals existed in the marinas. Concentrations of zinc never exceeded California’s water quality standards. In contrast, concentrations of dissolved copper in salt and brackish water marinas were frequently above California water quality standards established for the protection of aquatic life. Developmental toxicity tests on the copper-sensitive embryo of the mussel Mytilus galloprovincialis were conducted on 47 marina water samples. Eight of these samples showed a statistically significant toxic response and copper was the likely cause of the toxicity. Several copper toxicity models that account for copper bioavailability to aquatic organisms were used to predict toxicity for the 517 samples for which sitespecifi