Some features of walleye pollock spawn in the northern Okhotsk Sea in 20042006
The data of ichthyoplankton surveys in the northern Okhotsk Sea in 20042006 are analyzed. Spatial and vertical distribution of mature pollock and its eggs, age-size composition of the males and females at different stage of maturing are presented. The areas of high spawning activity are determined. Influence of oceanography conditions on distribution of mature fish and eggs is analyzed. Dependence of postspawning pollock distribution on feeding organisms distribution is revealed. Longer spawning with several spawning grounds is noted for the cases of wide and complicated age-size composition of the spawning stock. Spawning period of males is longer than females spawning as judged by proportion of males and females at different stages of maturing.