LONG-TERM VARIATIONS OF MACROBENTHOS STRUCTURE IN THE BLACK-RIVER ESTUARY (WHITE-SEA)

Long-term variations (1985-1992) of the species composition, total den sity, total macrobenthos biomass in the Black River estuary are relate d to changes in the salinity regime of the water body. These variation s do not influence the possibility to distinguish the marine and fresh ened zones, the border of which is determined by salinity 14-16 parts per thousand. They are not also related to distinguishing three subzon es (oligohaline, horohaline and brackish) with a specific set of domin ated species within the freshened zone. The highest integration of mac robenthos is due to increasing the water salinity, the highest differe ntiation is due to decreasing it.