Effectiveness of artificial reproduction of pink and chum salmon in the Sakhalin-Kuril Region

Catch dynamics of chum and pink salmon in the Sakhalin-Kuril Region did not correlate positively with the changes in their juveniles release from salmon hatcheries — the catches grew after the release of 500–600 . 106 ind. but decreased when the higher volumes were released. The effect of artificial reproduction of juveniles on the stocks of pink salmon was insignificant, so far as the fish from natural spawning grounds provided > 95 % of the catches in eastern Sakhalin. For chum salmon, the artificial reproduction was effective when the juveniles release did not excess 100 . 10 6 ind. in Iturup Island, 200–250 . 10 6 ind. in eastern Sakhalin, and 70 . 106 ind. in southwestern Sakhalin. So, the salmon hatcheries activity in the Sakhalin-Kuril Region requires adjustments to resolve contradictions between the natural environments and economic activities in the salmon water bodies; between the desired short-term and long-term economic outcomes and approaches to planning; between the fishery industry focused on exploiting natural stocks and the aquaculture developing the hatchery reproduction; between the mostly natural reproduction of pink salmon and predominantly artificial reproduction of chum salmon; and between the trends in salmon stocks dynamics in the Sakhalin-Kuril Region and generally in the Russian waters.