Contamination and Distribution of Persistent Organochlorine and Organotin Compounds in Deep-Sea Organisms from East China Sea

Deep-sea organisms collected from East China Sea (ECS) from depths of 89-512 m during 2001 to 2003 were analyzed for organochlorine (OC) and organotin (OT) compounds. Among OCs, concentrations of DDTs (up to 7900 ng/g lipid wt) were the highest and other OCs were approximately in the order of PCBs>CHLs>HCHs = HCB. The high DDT levels found in this study area and the higher ratio of p,p'-DDT indicates the continuing usage of this compound in this region. Among OTs, concentrations of butyltins (BTs) were the highest followed by triphenyltin (TPT). Concentrations of monooctyltin (MOcT) and dioctyltin (DOcT) in most of the samples were below detection limits. Significant positive correlations were found between δ^<15>N (‰) and lipid normalized concentrations of the most lipophilic OCs like PCBs, DDTs and CHLs showing their high biomagnification potential in marine food webs. No such relationship was found for HCHs, HCB, TBTs and TPT. Deep-sea fishes had increased burdens of DDTs, PCBs and CHLs when compared to fishes living in the upper water layer within a particular geographical origin. These findings suggest a long term downward vertical transport of organochlorine pollutants via the organic carbon flow and their recycling in the biophase of the deep-water. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.