Some results of monitoring for the pink salmon hatchery stocks from the Aniva Bay (Sakhalin Island)

Abstract

Several population parameters (length and dynamics of spawning run, size-sex composition, variability of morphological and physiological characteristics) are determined and indices of survival are calculated for the pink salmon hatchery stocks from the Aniva Bay of the 2008-2011 generations on the base of the cultured pink salmon differentiation by thermal marks on otoliths. The hatchery pink salmon begin their migration to the bay rivers in late July, together with the wild fish. Size-weight parameters of the fish and their variability are similar for the hatchery and wild stocks in this period, obviously because of low impact of hatcheries on natural reproduction and high portion of wild fish among the spawners used in the hatcheries (> 50 %). Mean portion of the hatchery-reared pink salmon on spawning grounds of the main rivers was 17.9 % in the 2010-2013, the coefficients of their return varied from 1.0 % to 6.4 % that was lower than for the wild fish.

Keywords

• горбуша
• рыбоводные лососевые заводы
• маркирование
• структура нерестового стада
• оценка численности
• индексы выживаемости