СОСТОЯНИЕ ДОННЫХ СООБЩЕСТВ СЕВЕРО-ЗАПАДНОЙ ЧАСТИ ЧЕРНОГО МОРЯ В УСЛОВИЯХ ИЗМЕНЕНИЯ РЕЧНОГО СТОКА

Certain changes in the structure and distribution of the bottom communities hi occurred in the north-western part of the Black Sea, in the region between the Dnieper and Danube, during the last 6 years (1978-1983). Two new biocenoses (Nereis succinea and Balanus) have appeared. The areas occupied by the Mya arenaria biocenosis have extended greatly, especially in the region influenced by the Dnieper flow. Degradation of the Melinna palmata biocenosis was observed in this region. All these changes are caused by intensification of mass mortality of the benthic fauna and by freshening of water in the region between the Dnieper and Danube in recent years.