Characteristics of the spawning stock of chinook salmon Oncorhynchus tshawytscha from the Apuka River (northeastern Kamchatka)

Relation between biological parameters of Pacific salmons of the genus Oncorhynchus and their population dynamics off the northeastern Kamchatka Peninsula

“…It was noted earlier that when the total abundance of Pacific salmon increases, the proportion of 5 year old chum salmon breeders also increases, while the proportion of 4 year old chum salmon breeders decreases (Zavarina, 2008). We observed the same phenomenon in the Olyutorsky area (Klovach et al, 2013;El'nikov and Gritsenko, 2014). In odd years, the proportion of 4 year old breeders increased, whereas 5 year old breeders were markedly dominant in even years.…”

“…6). In years of low pink salmon abundance (i.e., odd years), chum salmon in catches were especially abundant; there were two such years within our study period, 2008 and 2010 (Klovach et al, 2013).…”

“…Verkhnyaya Krasnosel'skaya 17, Moscow, 107140 Russia e mail: norma@vniro.ru ing in the areas of the Karaginsky and Olyutorsky gulfs (Zorbidi, 2010;Klovach et al, 2011). It is well known that the pink salmon is represented by two reproductively isolated lines of even year and odd year breeders, considerably different in abun dance in most areas.…”

“…In years of high abundance, the pink salmon strongly affects biological parameters via food supplies both of its own and of other salmon species fattening together with it in the ocean (Bugaev, 1995;Volobuev, V.V. and Volobuev, M.V., 2000;Klovach, 2003;Volobuev and Marchenko, 2011;Karpenko et al, 2013;Klovach et al, 2013;El'nikov and Grit senko, 2014). Hence, it is necessary to determine the relation between the interannual dynamics of such integral parameter as the hard roe (ovary) yield to abundance and biological parameters of Pacific salmon in different area.…”

“…Hence, it is necessary to determine the relation between the interannual dynamics of such integral parameter as the hard roe (ovary) yield to abundance and biological parameters of Pacific salmon in different area. The possibility that this parameter can be used to estimate the size of Pacific salmon catches makes this challenge especially impor tant (Gritsenko and El'nikov, 2013).…”