Lipid biogeochemistry of plankton, settling matter and sediments in Trinity Bay, Newfoundland. I. Lipid classes

Seawater, settling particles and sediments were sampled in Trinity Bay, a f jord-like bay on the east coast of Newfoundland, to determine the nature an d rates of lipid inputs. At the height of the spring bloom, diatom triacylg lycerol storage increased in response to lowered nitrate and silicate conce ntrations. This was followed by increased concentrations of phospholipids w hich coincided with biomass increases in dinoflagellates and zooplankton. S ediment trap results from 50 100 m show that planktonic lipids appear to be transferred with little alteration through the water column to benthic and demersal food webs. Fluxes are high, especially in spring, and incorporati on into the food web seems to be very efficient with little loss through bu rial in the sediments, Much higher lipid concentrations are seen in sedimen ts closer to shore where terrestrial plants are likely to be an important c ontributor to the lipids. The sediment trap results also show that the use of poisons can cause an overestimation of fluxes of some acyl lipid classes , while leaching during deployment may cause an underestimation of fluxes o f most lipid classes. (C) 1998 Elsevier Science Ltd. All rights reserved.