Features of the Structure of Macrozoobenthos of Watercourses in the Conditions of an Intact, Heavily Swamped Area: The Basin of Lake Vodlozero and the Vodla River (Vodlozersky National Park, Lake Onega Basin)

The features of the composition, diversity, abundance, and trophic structure of macrozoobenthos in nine rivers of the Vodlozersky National Park and its buffer zone (Ileksa, Verkhnyaya Okhtoma, Novguda, Kelka, Okhtoma, Sukhaya Vodla, Vama, Lepruchei, and Vodla) are analyzed. A total of 17 stations were surveyed in the summer of 2019 and 2022. Vodlozersky Park is one of the largest untouched areas in Europe, characterized by high swampiness and low-mineralized, highly colored waters. In the macrozoobenthos of rivers, chironomid larvae are leaders in abundance. Along with them, there are numerous caddisflies on boulder–pebble soils, oligochaetes on sandy soils, and bivalves on silt–clay–detritus soils. The areas located at the source of the lake are particularly abundant. The greatest α-diversity is observed in the biotope of boulder–pebble soils. The differences between biotopes in the ratio of trophic groups lie in the predominance of collectors–filters in fast flows and collectors–gatherers in slow flows.