The seasonal and annual fluctuation of the sperm whale, Baird’s beaked whale, killer whale, the globicephalids, and the dolphins and porpoises in the past 11 years are discussed. The sperm whale is abudant in the northern areas, in summer and autumn seasons. Its density fluctuates with a period of 4 years. The Baird’s beaked whale is found only in the northern areas in the season from spring to autumn. The killer whales is relatively abundant in the northern areas.
The globicephalids and the delphinids from the warmer waters migrate into the northern areas in summer season.