First Detection of the Invasive Amphipod Gmelinoides fasciatus (Crustacea: Amphipoda) in the Vygozero Reservoir and the Water Catchment of the White Sea-Baltic Canal (Republic of Karelia)

The Vygozero Reservoir is located in the Subarctic territory, the north of the European part of Russia, and is a component of the White Sea–Baltic Waterway. The results of studies of the littoral bottom biocenoses of the Vygozero Reservoir, Lake Voitskoe and the Segezha River in June 2025 are presented. It is shown that the invasive species Gmelinoides fasciatus (Stebbing 1899) (Crustacea: Amphipoda) was identified at littoral stations located close to shipping routes. The fairly rapid dispersal of the Baikal species G. fasciatus to the littoral of other water bodies gives reason to assume that in the coming years these amphipods may colonize the entire littoral zone of the Vygozero Reservoir.