Известия ТИНРО (Dec 2021)
Comparative analysis on distribution of common cetacean and fish species in the Barents Sea
Abstract
Comparative analysis of cetacean and fish species distribution in the Barents Sea is conducted on the data of joint Russian-Norwegian ecosystem surveys in August-October of 2005–2014. The number of observed minke whale (Balaenoptera acutorostrata), humpback whale (Megaptera novaeangliae), fin whale (Balaenoptera physalus), white-beaked dolphin (Lagenorhynchus albirostris), and harbor porpoise (Phocoena phocoena), as well as the acousticmeasured distribution density of fishes, as capelin (Mallotus villosus), polar cod (Boreogadus saida), herring (Clupea sp.), cod (Gadus morhua), haddock (Melanogrammus aeglefinus), saithe (Pollachius virens), blue whiting (Micromesistius poutassoumes), redfish (Sebastes sp.), norway pout (Trisopterus esmarkii), and fish fingerlings are summarized by the squares 50 x 50 km and maps of their distribution are drawn. A degree of overlapping between distributions of cetacean and fish species is estimated for each pair of species, as ratio of number of the squares where the species were presented together to total number of the squares where the species were found. Associations between cetaceans and their potential prey are determined by the methods of principal components and correlation analysis applied to the log-transformed data. Distribution of the widely distributed cetaceans, as minke whale and white-beaked dolphin, overlapped largely (up to 42 %) with many of studied fish species, therefore their possible predation on these species was significant. On the contrary, locally distributed cetaceans, such as harbor porpoise, had possibly lesser impact on fish because of low overlapping with their distribution (< 11 %). By the results of correlation analysis, capelin and polar cod were the priority potential prey for baleen whales (p < 0.01 and p = 0.02, respectively), whereas cod, haddock, blue whiting, and redfish – for toothed whales (p = 0.02, 0.01, 0.02, and < 0.01, respectively), in particular for white-beaked dolphin.
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