THE PHYTOPLANKTON COMMUNITY STRUCTURE AND ITS RELATION TO DIMETHYLSULFONIOPROPIONATE (DMSP) DISTRIBUTION DURING EARLY SUMMER BLOOM (PHAEOCYSTIS) IN KONGSFJORDEN, SVALBARD

Abstract

Kongsfjorden is a glacial fjord in the Arctic that is influenced by both Atlantic and Arctic water masses. This area is affected by large range of environmental factors, and it is important to measure, characterize and monitor the ecological status. The size structure and species composition were investigated during early summer of 2008 to 2010, with special attention to small phytoplankton (cells <20 μm in diameter). To aid the interpretation of phytoplankton data, hydrographic data were also collected. Measurements made on the phytoplankton included size fractionated chlorophyll, photosynthetic pigments by HPLC, cell counts by inverted microscopy. The Prymnesiophyceae Phaeocystis pouchetii was making huge bloom in outer site of Fjord, and small diatoms and flagellates were occurred in the most stations. The size fractionated chlorophyll a study was indicated that major contributor is the small-sized fractions in this area. The dimethylsulfoniopropionate (DMSP) was also measured to understand the intercellular DMSP content differences between dominant species, Phaeocystis pouchetii, and other diatoms.