The distribution of Fulmarus glacialis and Puffinus tenuirostris, in the North Pacific Ocean and the Okhotsk Sea during the summer

Abstract

1) This paper is based on the data obtained by r. v. Tansei Maru, between June 1977, and July in Sanriku offshore waters, the southern sea of Hokkaido, and the Okhotsk Sea, and reports the distribution and habits of Fulmarus glacialis and Puffinus tenuirostris.2) The southern limit of F. glacialis in summer was approximately 39°-30'N and a sea surface temperature of 20°C was regarded as appropriate.3) In areas where the sea temperature was 11-17°C F. glacialis and P. tenuirostris were abundant.4) In the Okhotsk Sea, a cold upwelling zone existed in the vicinity of 100m isobath and the density of F. glacialis and P. tenuirostris was very high. This zone was estimated to a food supply for sea birds.5) Large flocks of more than 20, 000 birds, P. tenuirostris were seen in the Okhotsk Sea.