Prognosing of periods and spawning migration intensity in spring-spawning Baltic herring of the Gulf of Riga according to the temperature factor of environment

Abstract

The relations of prognostic importance between the temperature regime in the Gulf of Riga (Baltic Sea) in February, April, May, the winter severity and the beginning of spawning migration, mass spawning as well as the intensity of Baltic herring (Clupea harengus membras) migrations to the spawning grounds at the Latvian coast of the gulf are considered. The corresponding correlation coefficients and regression equations important in planning of Baltic herring pound net fishery are given.