Fatty acids in surface sediment at the Hebridean shelf edge, west of Scotland

Sediment samples were taken by multicorer from a site at 1000 m water depth on the Hebridean shelf edge, west of Scotland, nine times during the perio d April 1995 to July 1996, and the surface 1 cm was analysed for lipids. Th e aims of the study were to fa) determine the seasonal sources of the lipid inputs, and (b) assess the contribution of lipids of terrestrial origin to the lipid budget of surface sediments. The results indicate seasonal varia tion in the total fatty acid content, with highest concentrations in May, A ugust and September consistent with phytoplankton blooms in spring and autu mn. Bacterial biomass appears to increase in abundance in August and then s lowly decreases until April. However, sediment fatty acid profiles did not accurately reflect the known species succession within the sprint and summe r phytoplankton bloom. The general lack of longer chain fatty acids is cons istent with a predominantly marine input. (C) 1998 Elsevier Science Ltd. Al l rights reserved.