Pathways of the Amur pink salmon Oncorhynchus gorbuscha to the areas of reproduction

Abstract

Biannual sequence of high-numerous and low-numerous year-classes of pink salmon ( Oncorhynchus gorbuscha ) is disturbed rarely in the areas close to its spawning grounds where mostly local groupings are landed, as it is shown on the data of fishery statistics in many areas of Russian Far East for 1907-1986. The disturbances are related usually with by-catch of transitory fish, in particular for the Sakhalin-Kuril region. Dynamics of the pink salmon annual landings in the Amur correlates with its dynamics at northwestern Sakhalin, that allows to suppose the species migration from the Okhotsk Sea to its spawning grounds via northwestern Sakhalin. Besides, a part of the Amur pink is caught at the mainland coast of the Gulf of Sakhalin, but the landings in the Amur correlate well with this transitory area in even years only, when the run is stronger. The highest catches of pink salmon on the mainland coast of the Gulf of Sakhalin in 2015 could be ensured neither the Amur nor the Sakhalin groupings; a hypothesis on the Shantar groupings contribution is discussed. In general, high catches of pink salmon in Khabarovsk Region in 2015-2016 are possibly reasoned by its good survival and lowered fishery in the Sakhalin-Kuril region.