State of marine biota in the water area of the Muchke Bay’s Coal Terminal of the Tatar Strait

Abstract

An analysis of the species composition of phytoplankton and ichthyoplankton was carried out for the first time in the port water area of the Muchke Bay (Tatar Strait) in autumn. The species composition, distribution features and structure of macrozoobenthos were considered. Phytoplankton density is evenly distributed in the study area. The density of diatoms reached 97 % of the total phytoplankton density, and the biomass was 99 %. The microalgae Sceletonema costatum (Greville) Cleve, 1873 and Cylindrotheca closterium (Ehrenberg) Reimann & J.C.Lewin, 1964, species that live in polluted waters, were discovered. The development of phytoplankton in the autumn period was active, but the peak of flowering was not observed. Ichthyoplankton in October 2017 is represented by live eggs of Limanda sakhalinensis (Schmidt, 1904) (8 ind./m3), in September 2018 - by the larvae of Hexagrammos stelleri Tilesius, 1810 (0.003-0.056 ind./m3) and H. octogrammus (Pallas, 1814) (0.01-0.077 ind./m3). Up to 85 representatives of macrozoobenthos were registered from the research area, including 40 species of Polychaeta, 19 ones of Crustacea, 16 species of Mollusca, 5 ones of Echinodermata and 5 species of other fauna groups. After dredging, a decrease in the species diversity of phytoplankton, ichthyoplankton and macrozoobenthos was found in the samples.