Structure of Zoobenthos at Different Stages of Ecosystem Succession in Thermokarst Water Bodies of the Central Yamal Peninsula

Abstract The taxonomic composition, structure, and spatial distribution of zoobenthos have been studied in 25 water bodies the Arctic tundra. Eight types thermokarst bodies, representing stages succession cycle, identified for central Yamal Peninsula. Water initial cycle are located on hills, middle at edge valleys, latest valleys. In total, 161 species found; their abundance diversity vary within a wide range according to reservoir type. number per sample ranges 1–33, 0.02–23.40 thousand ind./m 2 , biomass 0.05–73.09 g/m . trophic status changes gradually from hypereutrophic beginning (bog stage) ultraoligotrophic (lake stage), becoming end (khasyrei stage). During succession, decreases due replacement small forms by larger ones: complex dominating chironomid through bivalves oligochaetes lake stages, gastropods gammarids cycle. Feeding preferences change phytophagous, spectrum (including filter-feeding), phytophagous detritus-feeding.