WHOI Arctic Group | Projects

Sediment traps have been deployed worldwide since the 1970's in order to quantify the amounts, composition, and timing of particle flux to the ocean floor. Particle production, consumption, remineralization and subsequent delivery to the deep ocean are important features of the biological pump, biogeochemical and climate cycles. Extensive research has been carried out in the Greenland, Iceland and Norwegian (GIN) Seas to characterize the biogeochemical processes of settling particles collected by sediment traps. The Woods Hole Oceanographic Institution and the Marine Research Institute, Iceland, have deployed a time-series sediment trap from 1986 to present in the Iceland Sea. The mooring is located 1420 meters below the surface at 68N, 12.6W. The Iceland Sea trap location straddles the boundaries between the Polar and Arctic Fronts allowing us to monitor the effects of changing contributions of cold Polar and warm Atlantic waters into the gyre which influence both atmospheric and oceanographic conditions. Further, the spring onset and magnitude of nutrient uptake by plankters in the Iceland Sea also seems to depend largely on the influx of Polar and/or Atlantic waters into the area.

Our 15 year time-series particle flux results have revealed large interannual particle flux variability both in the type and amounts of particles delivered to the deep sea. For example, prior to 1997, average annual total particle fluxes consisted of about 40% CaCO3 and 22% SiO2. Since 1997, we have observed an 8-10 fold increase in the annual total particle flux, which consists of about 80.5% CaCO3 and 5.9% SiO2. Similarly, we have monitored a 10-fold increase in foraminiferal production between 1997 and 2000. Although the foraminiferal flux increase is remarkable in itself, it comprises only 1% to the total carbonate flux in 1999, which is an almost pure bloom of C. pelagicus.