Всестороннее изучение бентоса позволяет не только видеть текущие изменения донных сообществ и лучше понимать, чтό происходило с ними в прошлом, но и с некоторой степенью достоверности прогнозировать их будущее. Многощетинковые черви являются одной из самых многочисленных и значимых групп бентоса, способных выступать своеобразными биоиндикаторами состояния среды. В настоящей статье предпринята попытка проанализировать изменения биогеографических групп полихет Печорского моря в сравнительно длительный период времени (около 50 лет), чтобы понять, кáк влияют изменения климата на соотношение биогеографических групп многощетинковых червей и, как следствие, могут ли полихеты в той или иной степени выступать в качестве биоиндикаторов. На основе анализа новых и прежних данных составлен список многощетинковых червей Печорского моря. Он насчитывает 198 таксонов (из них 186 определены до вида), относящихся к 127 родам, 37 семействам и 15 отрядам. Соотношение биогеографических групп полихет Печорского моря указывает на постоянство их биогеографического состава в течение последних 50 лет и является ещё одним подтверждением цикличности процессов, происходящих в Арктике.

The modern taxonomic and geographical composition, trophic mode and spatial distribution of polychaete worms - one of the most important components of the bottom ecosystems of the Pechora Sea, is studied. This area characterized by the special abiotic conditions, a high level of biological production, a variety of biotopes and numerous populations of rare and protected species. According to the materials of the last expeditions in the Pechora sea, 198 taxa of polychaete worms were identified including 165 species belonging to 113 genera, 34 families, and 14 orders. Everywhere the species diversity of polychaetes and stress stability of their populations was high, with the exception of small areas, located near entrance to the Pechora and Khaypudir bays with amount of river runoff. The density of settlements widely varied from 26 to 7144 ind./m(2). Density gradients are most pronounced in the south-eastern shallow part of the Pechora Sea and in a lesser extent in the north-western of region. The spatial distribution of polychaete biomass is also heterogeneous, but varies much less in absolute terms from 0.7 to 387 g/m(2). Four major groups represent the trophic mode of polychaete bioresources. More than half of the total biomass is created by surface detrivorous, a few less than a third - by subsurface detrivorous, 2% - by suspension feeders, and 10% - by carnivorous. The 80% of all polychaetes constituted only by six species, and the most significant of which are Spiochaetopterus typicus and Maldane sarsi. During the last 70 years the number ratio of species belonging to main biogeographic groups remains stable, although the taxonomic list is constantly increasing. The stable state of polychaete taxocene, playing the significant role in the bottom ecosystems, assumes the stable state of bottom biocenoses of the Pechora Sea in general.

Using the materials collected in 2015, modern data have been obtained on the polychaete species composition and quantitative distribution in the West Spitsbergen area in winter. Polychaete species complexes corresponding to different habitat conditions have been identified in the outer and inner parts of the bays. The distribution of the Polychaeta communities proved to be dependent on the bottom sediment composition, depth, and specific hydrological regime.

On the basis of materials collected during 1995, 1997, 2000, 2001, 2003, 2007, 2010-2012 on the transect "Kola Meridian" distribution of polychaetes in the gradient of environmental factors has been analyzed. Dependence of species composition and quantitative characteristics of polychaetes from the type of bottom sediments and the peculiarities of the hydrological regime has been revealed

The species composition of the polychaetes derived from ichthyological and Sigsbee trawls in the Pechora and Kara seas in 2012 was studied and compared with the grab survey data of 1993–1995. The distribution of the large sabellidae, nektobenthic, and bathypelagic species that are poorly caught by a grab has been determined for the first time. Changes that were observed in the biogeographical polychaete structure in the Kara Sea (a higher proportion of the boreal species and a lower proportion of the Arctic species) may reflect a response of zoobenthos to the Arctic warming in the late 20th and early 21st centuries.

Based on the data collected in five marine expeditions of the Murmansk Marine Biological Institute from 2002 through 2007, the spatial and temporary variability of benthic communities in the Central Depression of the Barents Sea (licensed plot of the Shtokmanovskoe condensed gas deposit) has been analyzed. The range of quantitative characteristics and the variability of species composition of deep-water zoobenthos have been determined. The influence of an insignificant change in the collecting method on the obtained results has been examined.