The killer whale (Orcinus orca) in the northeast Atlantic

During the last two or three years schools of killer whales have often been reported in fjords and even harbours in Norway. The fishermen and their organizations fear that an increasing number of killer whales may decimate the growing population of Atlantic- Scandian herring. In order to obtain more information about the whales a marking cruise was made by the Institute of Marine Research, Bergen, to Kristiansund on the coast of Møre in January 1978. On the cruise about 30 killer whales were observed. Two whales were marked and possibly one more. Before marking the killers were not afraid of the vessel. After a hit of a mark, the whales ran away, and it was impossible to approach the school again. The whales also could identify the marking vessel amongst other ships. When the school ran away, the females with calves went first, and then, side by side, the rest of the animals in the school. During the flight, the whales dived and surfaced synchronously. Whalers have observed that when scattered killer whales are frightened, they always gather in a school before they run away. Fishermen have observed killer whales gathering herring by swimming in circles around the fish. When a compact school has been collected, two or three whales at time swim inside the ring and eat the herring while the rest of the killers hold the circle. Previous unpublished data from examination of stomach contents show that killer whales eat herring, squid and seals. ( The skin of the seal was found inverted in the stomack.) Small brown-reddish calves in the schools of killer whales found near Kristiansund in January, confirm earlier statements that birth occurs in November -December