Wax ester composition of the dominant calanoid copepods of the Greenland Sea/Fram Strait region

Abstract

The composition of the intact wax esters of Calanus hyperboreus, C. finmarchicus, and C. glacialis from the Fram Strait area of the Greenland Sea was studied. In addition the fatty acid and alcohol composition of the wax esters was analysed. All copepods were rich in wax esters, especially C. hyperboreus in which long-chain wax esters were generally more abundant than in the other species. The wax ester composition was species dependent but strongly overlapped by spatial variabilities. Because phytoplankton fatty acids were partially incorporated directly into wax esters, the composition of the wax esters was widely influenced by the phytoplankton community which itself varied considerably in the Fram Strait region. Thus, the wax esters of the polar species, collected in the North East Water Polynya near Greenland, were dominated by diunsaturated compounds in the range from C32 to C44. The shorter chain components resulted from a combination of palmitoleic acid which is typical of diatom lipids with long-chain alcohols. In the marginal ice zone, higher levels of polyunsaturated wax esters were detected due to the presence of the 18:4 fatty acid, typical of a summer phytoplankton population.