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 fjord-like bay on the east coast of Newfoundland, to determine the nature and rates of lipid inputs. At the height of the spring bloom, diatom triacylglycerol storage increased in response to lowered nitrate and silicate concentrations. This was followed by increased concentrations of phospholipids which coincided with biomass increases in dinoflagellates and zooplankton. Sediment 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 incorporation into the food web seems to be very efficient with little loss through burial in the sediments. Much higher lipid concentrations are seen in sediments closer to shore where terrestrial plants are likely to be an important contributor 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 of most lipid classes.