Effect of the mariculture of the Japanese scallop on foraminifera assemblages in Alekseev Bight, Sea of Japan

Abstract

The species composition and population densities of foraminifera were studied in scallop farming grounds in Alekseev Bight (Amurskii Bay, Sea of Japan). Ninety-one species of foraminifera were identified; members of the Elphidiidae, Discorbidae, and Ataxophragmiidae were numerically dominant. When the scallop mariculture farm was in operation, the species composition of foraminifera in farming grounds was impoverished and their population densities were an order of magnitude lower than at more distant locations. Between 1988 and 1995, after the liquidation of the farm, the species diversity and population density of foraminifera in farming grounds increased, while there was a general decline of the foraminifera population in the bay. The highest density and species diversity of foraminifera occurred on coarse silty sand and small silty pebbles, and the lowest species diversity was found on silty sediment.