Microbial community of the Coastal Zone of Kola Bay under anthropogenic impact

This study presents the results of a comprehensive research of the composition and structure of microbial communities in the coastal soils of Kola Bay, Barents Sea, under conditions of anthropogenic pollution. A general decline in the taxonomic and functional diversity of microbial communities was observed. The most diverse and stable microbial community was found in the supralittoral zone soil, which is less affected by chemical pollution and subjected only to recreational pressure. The taxonomic structure of the microbiome in the oil-polluted zone showed an increased ratio of Proteobacteria among bacteria and Sordariomycetes among fungi, along with a decrease in community diversity and evenness. High levels of oil and heavy metal contamination led to an increased ratio of bacterial groups adapted to anaerobic conditions and parasitic groups of microscopic fungi. Significant positive correlations were found between oil product content and bacterial groups involved in sulfur oxidation, and negative correlations with nitrogen-cycle microorganisms and mycorrhizal fungi. A positive relationship was identified between mycorrhizal fungi and mineral nutrient elements, and a negative relationship between nitrogen-cycle functional groups and heavy metal content (Cr, Fe, Ni, As, Se, Mo). A decline in the abundance of hydrocarbon-oxidizing bacteria was noted in the oil-contaminated area, possibly indicating high toxicity of the pollution and insufficient efficiency of anaerobic degradation.