Biomass of the Population of Invasive Gmelinoides fasciatus (Crustacea: Amphipoda), Its Production during the Vegetation Season, and Its Bioresource Value in Lake Onega

The total biomass of an invasive amphipod, Gmelinoides fasciatus , in Lake Onega has been estimated for the first time based on our own data and published data; it ranges from 1.6 to 2.2 thousand t of wet weight for the entire water body. Its production over the growing season varies from 2.9 to 4.0 thousand t. The biotope with the richest stock of this species (reed thickets, where the biomass of the crustacean can reach 39 g/m 2 ) is located mainly in the northern part of the lake. The possibility of considering G. fasciatus a potential commercial species with an estimated total allowable catch of up to 1.5–2.0 thousand t per year is discussed.