Composition and distribution of the pelagic and sympagic algal assemblages in the Laptev Sea during autumnal freeze-up
The phytoplankton and ice algal assemblages in the Siberian Laptev Sea during the autumnal freeze-up period of 1995 are described. The spatial distribution of algal taxa (diatoms, dinoflagellates, chrysophytes, chlorophytes) in the newly formed ice and waters at the surface and at 5 m depth differed...
| Published in: | Journal of Plankton Research |
|---|---|
| Main Authors: | , , , |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
2000
|
| Subjects: | |
| Online Access: | http://plankt.oxfordjournals.org/cgi/content/short/22/5/843 https://doi.org/10.1093/plankt/22.5.843 |
| Summary: | The phytoplankton and ice algal assemblages in the Siberian Laptev Sea during the autumnal freeze-up period of 1995 are described. The spatial distribution of algal taxa (diatoms, dinoflagellates, chrysophytes, chlorophytes) in the newly formed ice and waters at the surface and at 5 m depth differed considerably between regions. This was also true for algal biomass measured by in situ fluorescence, chlorophyll (Chl) a and taxon-specific carbon content. Highest in situ fluorescence and Chl a concentrations (ranging from 0.1 to 3.2 μg l–1) occurred in surface waters with maxima in Buor Khaya Bay east of Lena Delta. The algal standing stock on the shelf consisted mainly of diatoms, dinoflagellates, chrysophytes and chlorophytes with a total abundance (excluding unidentified flagellates <10 μm) in surface waters of 351–33 660 cells l–1. Highest algal abundance occurred close to the Lena Delta. Phytoplankton biomass (phytoplankton carbon; PPC) ranged from 0.1 to 5.3 μg C l–1 in surface waters and from 0.3 to 2.1 μg C l–1 at 5 m depth, and followed the distribution pattern of abundances. However, the distribution of Chl a differed considerably from the distribution pattern shown by PPC. The algal assemblage in the sea ice, which could not be quantified due to high sediment load, was dominated by diatom species, accompanied by dinoflagellates. Thus, already during the early stage of autumnal freeze-up, incorporation processes, selective enrichment and subsequent growth lead to differences between surface water and sea ice algal assemblages. |
|---|