Distribution and composition of fatty acids in muscle lipids of inshore fish and deep water sharks from the eastern Mediterranean

Abstract

Total lipid content and fatty acid composition were analysed in muscles of inshore fish ( Diplodus sargus, Lithognathus mormyrus) and deep water sharks ( Centrophorus granulosus, Galeus melastomus). The inshore fish were obtained from Haifa Bay, which is slightly contaminated by mercury, and from 40 km south of the bay, a relatively clean area. Higher mercury levels were found in fish from Haifa Bay compared with fish of the same size and species from the relatively clean control area. Nevertheless, mercury levels in deep water sharks (1300–1500 m water depth) caught in the eastern Mediterranean were revealed to be higher than in the inshore fish. Lipid content and fatty acid composition were similar in the two inshore fish species for both areas. No correlation was found between the reported mercury levels (Hornung & Kress, 1991) and fatty acid composition in the fish from the two areas. The fatty acid composition and lipid content of the two shark species were similar. There was no correlation between mercury concentration and fatty acid composition or lipid content in the muscle of the sharks.