Vågehvalundersøkelser ved Spitsbergen og i Barentshavet i mai og juni 1972

Abstract

Small whale investigations were carried out in the month May and June 1972 with two whaling vessels in the area off Svalbard and in the Barents .Sea. As far as possible all whales observed during the cruise were recorded. Poor weather was probably the reason why only 10 minke whales (Balaenoptera acutorostrata) and 2 killer whales (Orcinus orca) were observed in the beginning of May off Spitsbergen and only 3—4 minke whales and 2 killer whales near Centralbanken. During the period 10—16 June two fin whales (Balaenoptera physalus} but no minke whales, were observed off Spitsbergen. The weather was better in the Barents Sea, and minke whales were found in areas with good food conditions. Between 24—27 May 50—60 minke whales were observed at Østbanken, and between 3—10 June 80 minke whales, 7 killer whales and 2 fin whales were seen in the area Østbanken — Lewis Hole. At Nordkappbanken 100—200 white beaked dolphins (Lagenorhynchus albirostris) were observed. Altogether 39 females and 8 males of minke whales were caught by the two vessels. General biological data including total length and 20 body measurements were sampled from all the catch. Blood and tissue samples were collected for a study of population criteria. Of the females 24 were sexually immature and 15 mature. All the mature females were pregnant, which supports the earlier statements that the minke whales in the north Atlantic give birth every year. All the foetuses were found, and 14 of these measured from 29.0 to 80.3 cm with a mean lenght of 54.0 cm. The 15th was an embryo with a length of 8.5 mm. This material indicates a pairing season between January and May. From the small numbers of corpora in the ovary it may be oncluded that the females in the catch are relatively young. The length at sexual maturity and the length distribution in the catch are nearly the same as in previous findings. Examination of stomach contents showed that the whales had fed on krill, capelin and polar cod.