PT13 Aquatic Ecotoxicology I
Exhibit Hall
8:00 AM - Tuesday
(PT186) Effect of TBT and PAHs in Contaminated Waters on the Survival of Ark Shell Clams, Scapharca broughtonii.
Lee, K.-T.1, Lee, J.-S.1, Kim, C.-K.1, Kim, D.-H.1, Park, K.-H.1, Shim, W.-J.2, Oh, J.-R.2, 1 Institute of Environmental Protection & Safety, NeoEnBiz Co., 549-11 (Rm 201), Banpo-dong, Seocho-gu, Seoul, Korea, Korea2 South Sea Institute, Korean Ocean Research and Development Institue, Jangmok, Geoje, Kyungsangnamdo, Korea, Korea
ABSTRACT- Ark shell clams, Scapharca broughtonii, are economically important edible bivalves and widely cultivated in the south coast of Korea. Recently, the production of ark shell has been dramatically decreased. The reason is still not evident, but many fishermen accused that the chemical pollution could be closely related to the decline of shellfish population. Recent research results showed that the concentration levels of TBT and PAHs are considerably increased in Korean coastal environments especially near the shipbuilding docks, harbors and industrial complexes. In the present study, a series of experiments using ark shell as a test organisms were conducted to assess the toxicity of PAHs and TBT in both laboratory-spiked and field collected waters. Juvenile S. broughtonii was exposed to salinity-adjusted freshwater and coastal waters collected from sites near shipbuilding dock and simultaneously ark shell clams were exposed to 0.01-100 
g/l of PAH mixture and TBT, respectively, in a static renewal system for 40 days. Mortality was checked twice a day and dead individuals were removed quickly. Additionally, number of unattached clams was counted in each treatment occasionally. TBT was relatively toxic to clams compared to PAH mixture. All clams were dead after 10 d of exposure to 10 and 100 g/l of TBT. The LT50 of clams exposed to 1, 10 and 100 g/l of TBT were 25, 7.5 and 3.5 d, respectively. However, most clams (>90%) survived in Control and 0.1 g/l of TBT and all PAH treatments for 40 d. Clams exposed to some freshwater and estuarine field samples began to die after 3 days of exposure and half of clams were dead within 7 d. Chemical concentration of TBT and PAHs in field-collected waters were measured and compared to the observed mortalities of clams. S. broughtonii could be successfully used in the assessment of TBT toxicity in spiked and field-contaminated waters.
Key words: Scapharca broughtonii, ark shell clam, TBT, PAHs