As inhabitants of the epipelagic zone (0–200 m), salmon dwell mainly in the upper layer (0–50 m). The pascual area of Pacific salmon in wintertime is located between 40 and 45° N in the Subarctic or Arctic front, marked by high biological and fishery productivity. With the coming of spring, the warming of the upper layers of water and abundant plankton development the zone of active life shifts towards the North and Northeast. Salmon follow it without leaving the eutrophic area, which is the reason for their rapid growth. Masu salmon is the only type of Pacific salmon found only on the Asian shore, mainly in the Sea of Japan. Chum and pink salmon prevail on both sides of the Pacific — from the Peter the Great Bay and San Francisco to the Bering Strait.