ABSTRACT
In August-September 2015 in the southwest part of the Kara Sea, visual censuses of ringed seal (Phoca hispida) and bearded seal (Erignatus barbatus) from research vessels were carried out in the water area of 49 814 km2. For the first time, for calculation of abundance and density on ice-free area the SEAL-CALCULATION (TYULEN-RASCHET) software was used with application of separate extrapolation method by the selected sectors. Calculation for the whole census polygon yielded abundance of ringed seal of 4163 ± 16.9% and abundance of bearded seal of 1026 ± 28.4%. On the basis of the census results, a preliminary estimation of distribution of pinnipeds by various depths is presented.
Subject(s)
Phoca , Seals, Earless , Animals , Arctic Regions , Demography , Environmental Monitoring , Oceans and Seas , SeasonsABSTRACT
The study of the most abundant components in freshwater plankton in the Gulf of Ob and Taz Estuary in the summer-autumn season has demonstrated that the abundance and biomass of bacteria are stable and typical for mesotrophic waters during active microalgae vegetation. The abundance of viral particles varies in the range which is reported for unproductive or medium-productive water bodies. The environmental factors affecting affect the development and patterns of bacterio- and virioplankton distribution are considered.
Subject(s)
Bacteria/isolation & purification , Microbial Consortia/physiology , Seawater/microbiology , Seawater/virology , Viruses/classification , Viruses/isolation & purification , Bacteria/classification , Estuaries/classification , Russia , Water MicrobiologyABSTRACT
The seasonal dynamics of biomass and size structure of nanophytoplankton in the Central Murman (off the southern coast of the Barents Sea) are described according to the results of six-year continuous observations. The pattern of the annual successional cycle indicates that the nanophytoplankton community as a structural unit of coastal pelagic algocenoses represents a specific integrated ecological group of primary producers. The issue of a major contribution of nanoalgae to the total biomass and production of the autotrophic component of coastal ecosystems in Arctic seas is discussed.
