About walleye pollock (Theragra chalcogramma) spawning nearby the Southwest Kamchatka
It has been found from the results of ichthyoplankton surveys accomplished in 2007-2008 that the Okhotsk Sea waters on Southwest Kamchatka and the North Kuril Islands provide mass spawning of walleye pollock. The peak of the spawning can take place in the third decade of April or in early May, what is later, comparing to the peak spawning on the principal ground on West Kamchatka. The April-May spawning activities of walleye pollock on Southwest Kamchatka is usual judging by analysis of the archive data pool. That is allowing to suggest existence of "southern" spawning, coinciding in the time and scale to that in the Shelikhov Bay, although never taken into account in the course of standard ichthyoplankton survey in the first half of April. It has been suggested on the base of walleye pollock spawner growth rate studies that the "southern" spawning is provided by the East Kamchatkan population of walleye pollock, what normally uses to spawn on a mass scale in late April and early May. It has been assessed on the data for 2008 that the biomass of walleye pollock spawned in vicinity of the "Ozernovskaya Hollow" in the second half of April was 600 thousand tons approximately. It is suggested to provide a monitoring of the "southern" spawning at the expense of additional late April - early May ichthyoplankton survey southward from 53° N in the Okhotsk Sea waters and the area of the North Kurils.