The tendency of an increase in the abundance of macrozoobenthos species in Sevastopol Bay (Black Sea)
In: Inland Water Biology. MAIK NAUKA/INTERPERIODICA/SPRINGER: New York. ISSN 1995-0829; e-ISSN 1995-0837, more
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| Abstract |
In Sevastopol Bay, a decrease in the number of species and the disappearance of some zoobenthos communities was recorded back in the 1920–1930s and persisted until the 1960–1990s. Only five species of macrozoobenthos were the most resistant to high anthropogenic load and eutrophication in those years. The relative recovery of the species composition and the improvement of benthic biological parameters have been observed in the bay since the beginning of the 21st century. The zoobenthos was replenished by 39 new species which here were not marked earlier. The largest number of species was recorded for Mollusca, Crustacea, and Polychaete. These changes occurred even in those areas of the bay where previously benthic animals were absent in zoobenthos samples or found in very small numbers, conditionally a dead zone. The reduction in the eutrophic level, the improvement in the oxygen regime, and the expansion of the area with oxidizing conditions in the bottom sediment were the major factors in the improving benthic habitats in Sevastopol Bay. These ecological changes coincided with increase in the water temperature in the summer period. Positive zoobenthos tendencies are typical for Romanian and Bulgarian coasts in the last decade. |
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