Benthic macroinvertebrates of the northern Caspian Sea during recent rises in water-level

Data on benthic macroinvertebrates of the northern Caspian Sea in 1980–1991 were collected by the Caspian Fishery Research Institute. During the initial period of the water-level rise, the main trends in benthic macroinvertebrates were increases in the biomass of the main groups and decreases in the relative abundance of species of Mediterranean origin. There was no significant alteration in species composition. The increased abundance was due to improved trophic conditions and a decrease in the numbers of benthos-feeding fish. Some decrease in the relative abundance of species of marine origin was related to a decrease in water salinity.