The dynamics of the chinook salmon stock in Kamchatka River with regard to the fishery dynamics

Abstract

Current speciics of the condition of the stock of chinook salmon in Kamchatka River can be characterized by increased spawning runs which demonstrate signiicant structural transformations; the age composition has changed toward younger groups, and the percent of females has decreased. In the river basins where the ishery management is well organized, including the basin of Kamchatka River, the main factor, limiting the stock abundance and forming biological indexes of salmons is the ishery. An important instrument in interpreting the mechanisms of the inluence of the ishery onto the condition of the chinook salmon stock is the analysis of archive and current extensive data pools. The basis data pool consisted of Russian oficial commercial ishery statistics of chinook salmon catches on drift-net ishing at sea from 1952, drift-net ishing near shore in Kamchatsky Gulf and in the basin of Kamchatka River from 1934. For today 80% of chinook salmon stock in Kamchatka River are harvested by ixed nets set within Kamchatsky Gulf southward from the river mouth. The most impressive effects on the character and scale of the commercial use of chinook salmon are strongly depend on existing multispecies ishery of Paciic salmon in the basin, where the main target species is sockeye salmon. Aside of the nearshore ishery, not the last role in revealed transformation of the structure of the chinook salmon parental stocks and in the size-age composition and sex range, is played by the drift-net ishing at sea.