There were no special researchers on marine mammals on board of Norwegian vessels during ecosystem survey. However, the Norwegian observers of seabirds on boards «Eros», «Johan Hjort», and «Helmer Hansen», as far as possible in parallel also did observations of marine mammals.
8 species of marine mammals were observed during the observation period in the research area, reaching a total of 899 individuals.
The most observed species was white-beaked dolphin (Lagenorhynchus albirostris) (68.4% of all recordings). This species had a wide distribution in the research area (Figure 3.8.1). The most frequent observations of this dolphins were in areas close to obser ations of capelin, polar cod and Northeast Arctic cod aggregations with different densities, and this were in the western, central and eastern parts of the Barents Sea between 74°–80°N.
Figure 3.8.1 Distribution of toothed whales (a) and baleen whales (b) observed in August-September 2016.
Other observations toothed whales, besides white-beaked dolphin, consisted of two groups of Atlantic white-sided dolphin (Lagenorhynchus acutus) to the south of Spitsbergen. Previous years, this dolphin was not recorded in the Barents Sea during the research period. Also, one killer whale (Orcinus orca) and two harbour porpoise (Phocoena phocoena) were observed.
Out of the baleen whales of research area, minke whale (Balaenoptera acutorostrata), humpback whale (Megaptera novaeangliae) and fin whale (Balaenoptera physalus) (in total about 28.5% of all animals) were observed (Figure3.8.1). Minke whale were recorded mainly in the western, northern and southeastern parts of the research area. The densest concentrations of this species was seen on the southern ridge of Novaya Zemlya Archipelago coast in the herring aggregations that were observed, as well as on the southern tip of Spitsbergen and in the Great Bank area in capelin aggregations. In the northeastern parts of the Barents Sea minke whale were found in aggregations of juvenile polar cod and capelin, and in the southeast part of the Barents Sea it was in aggregations of juvenile cod, herring and other fish.
Recordings of the main groups of humpback whale were in the areas adjacent to the southern tip of Spitsbergen and in the Great Bank area, in capelin aggregations. Fin whale observed in the northern and western regions of the research area together with humpback whale and minke whale.
As a result of conducted study, main points of marine mammal research during Barents Sea ecosystem survey in August-September 2016 can be condensed to following:
- the main groups of humpback and fin whales were feeding at concentrations of capelin, primarily in areas south of Spitsbergen and on the Great Bank;
- other marine mammals in the Barents Sea were observed at concentrations of polar cod, capelin, herring, and cod fish;
- when compared with the last year, there was a decrease in the number of registered humpback whales by almost sevenfold;
- the Russian vessel «Fridtjof Nansen» did not fully cover the southern regions of the Barents Sea, and thus, data on the occurrence of the harbour porpoise was not received;
- total expert estimate of the number of main species of cetaceans in the whole area of the Barents Sea in August-September 2016 was estimated at 82.5 thousand individuals.