The biomass of benthos on the littoral and spring spawning grounds of Kurile Lake in the period of low abundance of foraging juvenile sockeye salmon in 1974

Characteristics of qualitative and quantitative composition benthos organisms on littoral spring spawning grounds Kurile Lake was given for the first time in 1974. Grounds typically consist intermiting plots pebble or gravel (clean covered by biocrust) with permanent sand component, sometime silty. The silt component rivers Srednaya Kirushutk is more impressive comparing to lake grounds. Chironomids group Crico­ topus aff аlgarum dominated all sites. In mid July highest biomass among near head Ozernaya River, at Severnoye Blizhneye Dalneye grounds, lowest Gavryushka Bay Etamynk River mouth. Spring were extensively different: maximum benthos, which almost totally consisted chironomids, recorded minimum — River.