DDT Residues in Pacific Sea Birds: a Persistent Insecticide in Marine Food Chains

THE accumulation and biological concentration of DDT and its metabolites^*within food chains of terrestrial, freshwater and estuarine ecosystems have been well documented. Significant residue concentrations have occasionally been reported in marine organisms, but these have usually been attributed to local sources of contamination⁴. The present study, which is based on analyses of collections of birds, fish and invertebrates from Pacific Ocean localities, indicates that DDT is also a component of marine ecosystems and that pelagic species may accumulate high concentrations of DDT residues. The results of the work with fish will be published elsewhere.