Accumulative characteristics of organochlorine compounds (OCs) in squid

The world-wide distribution of squid has led researchers to propose that th ese animals be used for biomonitoring of persistent organic chemicals in th e open ocean. However, their utility as a bioindicator species has not been examined in detail. The present study examined the accumulative characteri stics of organochlorine compounds (OCs) in the Japanese common squid Todaro des pacificus. Sampling was done in the Japan Sea and East China Sea, with a focus on whether contaminant levels in squid reflected those in surface w aters at particular sampling sites. Accumulation of OCs was primarily in th e liver, and concentrations did not vary with stage of maturation of the an imals. This suggests that an apparent equilibrium of OCs between liver and seawater may occur in a relatively short time at each sampling area. Moreov er, we found that it may be possible to estimate the concentrations of OCs in seawater from levels of alpha-HCH and PCB congener (Cl-5-Cl-9) in squid liver, because concentrations of these compounds in squid liver displayed a significant linear correlation with concentrations in seawater of 1-2 late r years at almost the same area. The present study indicates that the Squid Watch program using T. pacificus can be a useful biomonitoring method to estimate OCs levels in surface sea water of the open ocean.