Phytoplankton of the Khatanga Bay, Shelf and Continental Slope of the Western Laptev Sea

Resumo

The studies were conducted along the transect (11 stations) from the inner part of Khatanga Bay in the south to the Laptev Sea continental slope in the north in September 17—20, 2017. Four biotopes with different parameters of the pelagic environment, composition, quantitative characteristics and vertical distribution of phytoplankton have been distinguished: the inner part of the Khatanga Bay, estuarine frontal zone, western shelf of the Laptev Sea and continental slope area. The inner part of Khatanga Bay and the continental slope are characterized by the highest values of phytoplankton abundance and biomass, which reach 1 × 10⁶ cell/L and 160 mg/m³, respectively. The formation of the maximum at a depth of 45 m is typical for the phytoplankton vertical distribution in the continental slope area. Algal biomass in the maximum reaches 400 mg/m³ which is the highest value for the transect. Well-pronounced latitudinal zoning in the structure of phytoplankton communities has been determined in the western part of the Laptev Sea similar to that in other regions of the Arctic seas under a strong impact of Siberian rivers discharge.