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Vol. 19 (2016 year), No. 1, DOI: 10.21443/1560-9278-2016-1/2

Tyukina O. S., Kudelya Ya. S.
Biodiversity of phytoplankton communities of the Barents Sea in the summer of 2013

Information about taxonomic composition of phytoplankton communities of the Barents Sea in the summer of 2013 has been considered. It has been shown that biodiversity of phytoplankton communities was small in the observed water area, 43 species have been found referred to Diatoms, Dinoflagellate, Ochrophyta and Chlorophyta. Phytoplankton communities of the Barents Sea have been described as Arctic-boreal neritic complex of species with broad participation of cosmopolitan and oceanic forms

(in Russian, стр.0, fig. 0, tables. 0, ref 0, Adobe PDF, Adobe PDF 0 Kb)

Vol. 20 (2017 year), No. 2, DOI: 10.21443/1560-9278-2017-20-2

Tyukina O. S.
Abundance of phytoplankton communities of the Barents Sea in the first half of the growing season of 2013

Information on the abundance and biomass of phytoplankton communities of the Barents Sea in the summer of 2013 has been considered. Sampling has been carried out on board the research vessel "Professor Molchanov" in the course of the expedition "Arctic Floating University – 2013" in June, 2013 in the west (Kola Meridian), north-west, north (Franz Josef Land) and northeast (Novaya Zemlya) areas of the Barents Sea. The water samples have been collected from 32 stations on the surface layer of the sea water and from the layer of sharp changes in the density and temperature of the water – pycnocline – which lies at the depth of 20 to 50 m. Abundance and biomass of phytoplankton in the surface layer have varied from a few dozen to 74 thousand cells/L and 2.5 to 3 900 mkg/L; above the pycnocline layer – from several hundred to 63 thousand cells/L and from 0.9 to 3 000 mkg/L. As for the spatial distribution the greatest number of phytoplankton cells has been noted in the western region and the waters in the area of Franz Josef Land Archipelago, and the largest biomass – only in the western region. The average population size above the pycnocline layer is higher than in the surface layer, the average values of the biomass in two horizons are identical. Representatives of the two phylums of algae Bacillariophyta and Dinofita have been dominated in numbers in varying degrees in different areas. Diatoms are the main biomass formed in the northern part of the sea. Dinoflagellates have formed the main biomass in other regions in both the Barents Sea water horizons column.

(in English, стр.8, fig. 5, tables. 0, ref 13, Adobe PDF, Adobe PDF 0 Kb)

Vol. 21 (2018 year), No. 2, DOI: 10.21443/1560-9278-2018-21-2

Kalinina N. R., Anokhina V. S., Kravets P. P., Tyukina O. S.
Weight growth of different generation of the trout Parasalmo mykiss on Lake Imandra

The averaged indicators of the weight growth of four generations of trout at different temperatures in the time interval of the life cycle from the transfer of larvae to cultivation until the fish reaches a portioned commercial weight of 400 g when the first withdrawal of products for sale takes place have been analyzed. It has been shown that fish of different generations passes into the weight category "goods" sequentially, but after reaching different ages, while there is no direct correlation between the terms "generation formation" – "first withdrawal for sale". According to our data the most intensive weight growth of fish has been noted in the temperature range equal to 8–13 °C. An increase in the water temperature in the cages to 15–18 °C has led to a slowdown, and then to the suspension of the accumulation of fish biomass. In cages operating in the area of Kola NPP heated water trout of April generation gains the commercial weight of 400 g in 7–8 months after landing of larvae for cultivation, November trout – after 15 months. Trout of October and January generation reaches commercial weight at 11 and 9 months, respectively. The stretching of timing of biomass accumulation is most pronounced in the autumn generation of trout. It has been found that the greatest increase in weight per unit body (145.1 mg per day) is provided by the trout of the January biological group, the smallest – by the November trout (75.8 mg per day). The energy reserve of heat allowing for differently derived individuals to reach a commodity weight of 400 g, is in the range from 3 320 to 5 300 degree-day.

(in English, стр.8, fig. 6, tables. 4, ref 13, adobe PDF, adobe PDF 0 Kb)