Organochlorine Pesticides, Polychlorinated Biphenyls and Heavy Metals Residues in Myctophids off South West Coast of India

Though myctophids are widely distributed in the Indian oceanic waters and contribute to a large proportion of the deep-sea fish biomass, the information regarding the presence of lipophilic chemical contaminants and heavy metals in these lipid-rich lantern fishes are relatively scanty. Analyses on the occurrence of heavy metals, organochlorine (OCPs) and polychlorobiphenyls (PCBs) in myctophids from Indian waters showed presence of organochlorine pesticides in Diaphus watasei, Diaphus luetkeni and Myctophum obtusirostre. The prominent pesticides detected in the fish tissue include endrin, dieldrin, heptachlor epoxide, alpha-BHC and heptachlor. Dieldrin and heptachlor epoxide were detected in M. obtusirostre while DDT isomers in D. luetkeni. The total PCB levels followed the order D. luetkeni> D. watasei>M. obtusirostre and 2, 2', 3', 4, 5 - pentachlorobiphenyl and 2, 3, 3', 4', 6-pentachlorobiphenyl. Trace metals (Fe, Zn, Cu and Mn) Composition is comparable with other fish species reported and followed the order D. luetkeni> M. obtusirostre> D. watasei. Results showed that POPs and heavy metal levels in myctophid species studied were much below the regulatory limits.