STRUCTURE OF MACROZOOBENTHOS COMMUNITIES ON ODES’KA AND DNISTROVS’KA BANKS (NORTH-WESTERN PART OF THE BLACK SEA)

Abstract

Introduction. Underwater banks influence the distribution of fish due to the presence of certain habitats and feed resources, a significant part of which is produced in macrozoobenthos biocenoses formed in different biotopes. There exist very little data on the state and structure of the macrozoobenthos of Odes’ka and Dnistrovs’ka banks in the modern period. Aim. The purpose of the work was to determine the structure of macrozoobenthos groupings on different types of substrate of Odes’ka and Dnistrovs’ka banks in modern conditions. Methods. The material was collected in the districts of Odes’ka and Dnistrovs’ka banks with a 10×10 cm area quantitative accounting frame using light diving equipment. In the laboratory, the samples were processed in accordance with the generally accepted methodology. Mathematical data processing was carried out with the introduction of multivariate statistics methods. Results. On different types of the substrate of Odes’ka and Dnistrovs’ka banks, six communities of macrozoobenthos which significantly differed in structure were identified. The macrozoobenthos of Odes’ka Bank is characterized by high abundance, biomass and biodiversity indices compared to the macrozoobenthos of Dnistrovs’ka Bank. In the community of Mytilus galloprovincialis on Odes’ka Bank, species that were present in it before the period of intensive development of hypoxia were registered. In this community, the abundance of Mytilaster lineatus, Prionospio cirrifera increased, Alitta succinea was not found. The community of Chamelea gallina in Odes’ka Bank is characterized by high biomass and high abundance of Donax trunculus. Conclusion. The structure of macrozoobenthos communities in the area of the Odes’ka and Dnistrovs’ka banks is significantly different. Their state reflects the trend of structural changes in macrozoobenthos in the northwestern part of the Black Sea in the modern period.