Wax Esters in the Marine Environment: Origin and Composition of the Wax from Bute Inlet, British Columbia

Abstract

During severe winters large amounts of a solid lipid accumulate on the water surface and on the shores of Bute Inlet, a deep fjord on the mainland of British Columbia. Chromatographic analyses show that this wax consists chiefly of wax esters (48%), with minor amounts of hydrocarbons (4%) and triacylglycerols (6%). Dominant among the zooplankton in this inlet is the copepod Calanus plumchrus, which also is rich in wax esters (40–50% of dry weight). Except for the lack of polyunsaturation in Bute Inlet wax there is a close similarity between the wax ester, alcohol, and fatty acid compositions of C. plumchrus and Bute Inlet wax. The major hydrocarbon of both is pristane. We hypothesize that Bute Inlet wax is produced by some major change in water conditions which cause a massive kill of copepods. At winter temperatures this lipid is a solid and as such may accumulate on the beach. Copepods are the likely source for the wax esters in slicks and sediments reported from oceanic areas throughout the world. Key words: marine pollution, biological pollutant, lipid, hydrocarbon, wax, zooplankton, Copepoda