Stratification in Karnataka Reservoirs

Abstract

Stratification studies unveil some of the ongoing limnological processes related to fish production. In the present paper, an attempt is made to study the thermal and chemical stratifications in eleven reservoirs under Cauvery, Krishna and Sharavathy river systems in Karnataka. Harangi, Manchanbele and Bhadra reservoirs showed thermoclinity with clear demarcation of epi- and metalimnion. Oxygen profile was orthograde in Ghataprabha, Malaprabha, Narayanpur and Bhadra and clinograde in Harangi, Manchanbele, Nugu, Vani Vilas Sagar and Linganamakki. The strength of oxycline in water column especially during pre-monsoon influences the success of gillnetting operations, as the fish confines to the epilimnetic zone as observed in Manchanbele.