Infiltration phyto- and protozooplankton assemblages in the annual sea ice of Disko Island, West Greenland, spring 1996

Abstract

During the spring of 1996 we occupied a station on annual sea ice located several kilometers from Disko Island, West Greenland in water depths greater than 200 m. The goal of this 3-week field season was to characterize sea-ice communities and the underlying water column prior to, and during, ice break-up. A heavier than usual snow load depressed the sea ice below sea level and the snow-ice interface became flooded. Some of this flooded region subsequently refroze and the whole process repeated itself when additional snow accumulated. The infiltration phytoplankton and protozooplankton assemblages that developed in this region were abundant and diverse. Algal biomass in the infiltration layer was approximately an order of magnitude greater than in the underlying water column but an order of magnitude less than in the well-developed bottom ice community. The infiltration autotrophic assemblage resembled the bottom-ice assemblage while the protozooplankton assemblage was more similar to the water column assemblage.