Variability of vertical particle flux at the long-term observatory HAUSGARTEN in Eastern Fram Strait since the year 2000. Are we witnessing a change in epipelagic community structure?
The export and composition of particles has been measured by means of annually moored sediment traps at the AWI long-term observatory HAUSGARTEN in Fram Strait (79°/4°E) in 200-300m depth since the year 2000. The area of investigation west of Spitsbergen at a water depth of 2500m is temporally covered by sea ice during the course of the year. It is further influenced by the inflow of warm Atlantic waters at the surface as well as recirculating of the warm waters modified by out-flowing cold arctic waters. With our study we aim at tracing effects of environmental changes in pelagic system structure and impacts on the fate of organic matter produced in the upper water column in a region that is anticipated to react very sensible to climate change. We present data on the export of total particulate matter (TPM), particulate organic carbon and nitrogen (POC/PON), biogenic particulate silica (bPSi), carbonate (CaCO3) and protist composition achieved during the period 2000 - 2009. We observed a bimodal seasonal sedimentation pattern for almost all flux components. Annual fluxes showed greatest variation for TPM and CaCO3 (3-5 fold), and a drastic decrease in bPSi, a proxy for diatoms. The export of organic carbon and total biogenic matter on the other hand hardly showed any variation (1-2 fold) since the begin of the measurements in the year 2000. The results obtained during the 9 year period of the study are compared to the findings of sediment trap studies conducted in the Fram Strait during the end of the eighties and we will discuss our findings in regard to the changing environmental conditions in the area.
AWI Organizations > Biosciences > Deep Sea Ecology and Technology
ARK > XVIII
ARK > XX
ARK > XXI
ARK > XXIII
ARK > XXIV
ARK > XXV