Пути подходов горбуши разных сезонных форм к побережью о. Итуруп (Южные Курильские острова)

Abstract

Results are provided of a study of the pre-spawning routes of pink salmon Oncorhynchus gorbuscha to the Okhotsk Sea coast of Iturup Island (South Kuril Islands). The South Kuril pink salmon has two seasonal forms: early (summer) and late (autumn). The results obtained showed that pink salmon of different seasonal forms comes to the island in two ways, the early form (summer) preferably chooses the Strait of Catherine and goes north along the Okhotsk Sea coast to the Kuril Bay, and only 3 weeks later, a massive coming of pink salmon is noted through the Freez Strait and the northern part of the island to the south to the Prostor Bay. Reliable differences in the size and weight parameters of the early (summer) and late (autumn) forms are presented. From 2008 to 2011 there were two waves in the approaches of pink salmon producers. According to the change in the sex ratio during the spawning period, a change in the approach of one form of another was judged. The main catch since 2012 is the late form, the approaches of the summer pink salmon are extremely small. Discussed the status of the seasonal forms of pink salmon.