W10 PM Environmental Interactions of Marine Antifoulants
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 341-342

(ROM-1117-638996) Impacts of diuron and copper pyrithione on the sea urchin, Lytechinus variegatus.

Romano, J.¹, Rittschof, D.¹, McClellan-Green, P.^{1, 2}, ¹ Duke University Marine Laboratory, Beaufort, NC, USA² Department of Environmental and Molecular Toxicology, North Carolina State University, Morehead City, NC, USA

ABSTRACT- To control the growth of organisms on boats and marine structures, antifouling coatings are periodically applied to their surfaces. Unfortunately, these antifouling coatings leach into the aquatic environment where they have been shown to be extremely toxic towards non-target organisms. Recently, a number of compounds have been added as boosters to existing marine coatings in order to increase their efficiency and reduce their environmental impact on coastal ecosystems. We examined the toxic effects of two of these boosters, Diuron and copper pyrithione (CuPT). Adult variable sea urchins, Lytechinus variegates, were exposed to seawater containing 0.5, 1, 5, or 10 mg/L Diruon or 0, 5, 10, 15, 20, 25, and 50 g/L CuPT. The LC₅₀ and EC₅₀ (losing 5 or more spines per animal) for Diuron exposed urchins were determined to be 6.75 mg/L and 256.3 g/L, respectively. The LC₅₀ and EC₅₀ of urchins exposed to CuPT were determined to be 6.65 g/L and 368.2 ng/L, respectively. Next, gametes from healthy adults were exposed to the LC₅₀ concentrations of Diuron or CuPT. Fertilization rates decreased from a control value of 99.5% to 76.5 % for Diuron exposed gametes and 91.5% for CuPT exposed gametes. In addition, significant delays in embryo development (p<0.001) occurred as well as an increase in abnormal cell morphology (p<0.001). Critical time periods of development were also apparent in which a significant number of urchin embryos developed abnormally or further development was halted following exposure. These time periods ranging from 150-210 minutes at 23°C correspond to the 32 and 64 cell stage divisions. These cell stages are central in the formation of the various tissue layers. Continuous monitoring of biocide concentrations and further studies into their effects on larval development must be conducted to better understand biocide fate, effects and occurrence in other non-target species.

Key words: biocides, fouling, sea urchin, deveopment