High levels of organochlorine pollutants in the tunids Thunnus thynnus and Thunnus alalunga at the Balearic Islands

Abstract

Persistent organochlorine polluntant levels have been analysed in the muscle and liver of Thunnus thynnus i Thunnus alalunga in the Balearic waters. These two species are apical predators of the throphic web and they are directly exposed to high organochlorine compounds and indirectly by the bioaccumulation of pollution into the throphic web. The present results show that the pollutant concentrations analyzed are higher at T. thynnus than the concentrations at T. alalunga. In fact, the PCBs, DDT derivates and PBDEs leves in the T. thynnus liver are high. It is important to note that some of the studied subtances present higher legal concentrations for human consumption. It could be necessary to establish urgent monitoring programmes to evaluate the organochlorine pollutant concentrations in the apical levels of the throphic web. Moreover, it is important to determinate the social, sanitary, economic and ecològic implications by this pollution in the Balearic environment.