Composition and distribution of the pelagic and sympagic algal assemblages in the Laptev Sea during autumnal freeze-up

摘要: The phytoplankton and ice algal assemblages in the Siberian Laptev Sea during autumnal freeze-up period of 1995 are described. spatial distribution taxa (diatoms, dino- flagellates, chrysophytes, chlorophytes) newly formed waters at surface 5 m depth differed considerably between regions. This was also true for biomass measured by situ fluorescence, chlorophyll (Chl) a taxon-specific carbon content. Highest fluorescence Chl concentrations (ranging from 0.1 to 3.2 µg l -1 ) occurred with maxima Buor Khaya Bay east Lena Delta. standing stock on shelf consisted mainly diatoms, dinoflagellates, chrysophytes chlorophytes total abundance (excluding unidentified flagel- lates <10 µm) 351-33 660 cells -1. close Phytoplankton (phytoplankton carbon; PPC) ranged 5.3 C 0.3 2.1 depth, followed pattern abun- dances. However, shown PPC. assemblage sea ice, which could not be quantified due high sediment load, dominated diatom species, accompanied dinoflagellates. Thus, already early stage freeze-up, incorporation processes, selective enrichment subsequent growth lead differences water assemblages.