SPATIAL DISTRIBUTION OF PHYTOPLANKTON COMMUNITY IN THE KONGSFJORDEN, SPITSBERGEN

Abstract

The marine ecosystem in Kongsfjorden (79°N), a glacial fjord in Svalbard, is to a large extent well known with regard to hydrography, mesozooplankton and higher trophic levels. Research on primary production and lower trophic levels is still scarce and especially investigations from winter and spring periods. To determine the spatial distributions of phytoplankton communities in the Kongsfjorden, we analyzed algal samples during spring and autumn seasons using light microscopic examinations of slides prepared by the HPMA method. The data for the period 20172018 were collected. Temperature and salinity were higher in the outside than in the fjord. And regional differences were larger in autumn than in spring. In the spring of 2017, phytoplankton communities dominated by nano and pico sized phytoplankton such as Phaeocystis species. In 2018, the relative abundance was lower than in 2017 and diatoms such as Fragilariopsis oceanica showed a high ratio. The species diversity was relatively high in spring (79 taxa in 2017, 57 taxa in 2018) compared to autumn (52 taxa in 2017). Based on the results, it was determined that Phaeocystis sp., Pyramimonas sp., Paralia sulcata, Thalassiosira sp., Nano-size unidentified species and Pico-size unidentified species were indicate species in this study area. The vertical mixing of the water masses has been done to some extent, but the influx of the Atlantic water (AW) of high temperature and salinity will be more influential on the phytoplankton. A better understanding of the ecology of phytoplankton comminities in the Kongsfjorden will require multi-season and multi-year analyses.