Vertical particle fluxes in the coastal areas of the Barents and White Seas

The studies of vertical particle fluxes were performed in 2006–2007 in Dalnezelenetskaya Inlet (the Barents Sea) and Chupa Inlet (the White Sea). The average annual particle flux in Dalnezelenetskaya Inlet was 20–21 cm³/(m² day), or 1350–1400 mg/(m² day), while, in Chupa Inlet, it was 17–18 cm³/(m² day), or 500–550 mg/(m² day). The sedimentary matter is mostly represented by flocculent detritus less than 100 μm in size. Currently, the estimated sedimentation rate constitutes 0.9–1.1 mm per annum in the DI and 0.3–1.0 mm per annum in the Chupa Inlet.     

Structure and Productivity of the Phytocenosis in the Southwestern Kara Sea in Early Spring

Results of plankton biota studies in the southwestern Kara are presented. The spatial distribution of hydrochemical and hydrophysical parameters related to structural and functional characteristics of phytoplankton in the surface water is considered. The chlorophyll a concentration varied in the surface layer of the Kara Sea from 0.08 to 3.22 mg m^–3 (mean value 0.62 mg m^–3). Primary production varied from 0 to 1.92 mg C m^–3 day^–1 (the mean value of 0.42 mg C m^–3 day^–1) in the ice-covered water areas and was greater by a factor of four, ranging from 1.01 to 3.46 mg C m^–3 day^–1 (the mean value of 1.79 mg C m^–3 day^–1) in ice-free areas. In this case, the total algal biomass varied from 0.8 to 110.7 mg C m^–3 (mean value 10.6 mg C m^–3). It is shown that in the study period, waters from the western Kara Sea were more productive than the estuarine water areas of the Ob and Yenisei rivers. The activity of phototrophic phytoplankton in river waters was almost completely absent. It is established that the contents of nutrients and iron were higher than the threshold for limitation of phytoplankton development. The experiments showed that the production activity of phototrophic algae is restrained by light deficit beneath the ice.     

Polymer Particles in Solid Atmospheric Precipitation in the Northwestern Kola Peninsula in 2020‒2021

Doklady Earth Sciences - From December 2020 to April 2021, in the northwestern part of the Kola Peninsula, including the infrastructure of the city of Murmansk, the quantity of polymer particles in...     

Phytoplankton in the south-western Kara Sea: composition and distribution

The taxonomic composition and spatial distribution of pelagic algae were studied in the south-western Kara Sea in August-September 1981. In the north-western and easternmost regions of the study area the phytoplankton community, dominated by neritic diatoms and autotrophic dinoflagellates, was at the late spring bloom stage of the seasonal succession. In the central deep-water zone of the sea, there was a predominance of heterotrophic dinoflagellates from the genera Protoperidinium and Dinophysis , and the autotrophic compartment of the algal community was clearly in a stage of decline. The distribution of the phytoplankton assemblages followed closely the major routes of receding marginal ice zones. Three stages of the seasonal succession were established for the area of interest: (1) early spring (ice edge) bloom of arcto-boreal neritic diatoms; (2) late spring bloom of neritic diatoms and autotrophic dinoflagellates, fuelled by continental run-off; and (3) summer minimum with a predominance of heterotrophic dinoflagellates, followed by autumnal decline of the phytoplankton community.     

The structure and distribution of the phytoplankton community in the deep region of the Northern Kara Sea

The phytoplankton community and its distribution were investigated in the eastern branch of the St. Anna Trough and over the adjacent Kara Sea shelf in September 2011 and in August 2014. The spatial and seasonal differences in the phytoplankton structure were analyzed in connection with ice melting and changes in the temperature, salinity, and biogenic regime. Four 4 zones were defined: the Kara Sea shelf, the upper part of the St. Anna Trough slope, the lower part of the St. Anna Trough slope, and its deep part. It was shown that over the Kara Sea shelf where riverine runoff influence was observed, the phytoplankton community differs from the community of the St. Anna Trough in both investigated periods: in September and August. Rearrangement of the phytoplankton community was observed in the frontal zone associated with the upper part of the slope in September of 2011. The main features of this rearrangement were a change in dominant species composition and a 1.5–2-fold increase in the number and biomass of algae. Over the lower part of the slope and deep area of the St. Anna Trough in August 2014 and September 2011, the phytoplankton community was at different successive stages: in August, at the late spring and summer stage, and in September, at the summer–autumn stage.