Features of the distribution and habitat conditions of cetaceans in the Barents Sea in the summer-autumn period 2004–2021

Abstract

The aim of the paper is to identify the features of distribution of cetaceans in ice-free areas of the Barents Sea and adjacent waters in August-November and to characterize their habitat conditions (abiotic factors, distribution relative to mass fish species and macroplankton).The material of the study was the data collected by the Polar branch of VNIRO during the joint RussianNorwegian ecosystem surveys.Methods: geoprocessing and mapping of the studied parameters, comparative and statistical (principal component and correlation) analysis of the data.Results: Cetaceans were mainly observed in the western Barents Sea and distributed in waters with depths of from 23 to 2294 m, at temperatures of –1.9…10.7 °C and salinities of 33.0–35.2, the weighted averages of these parameters were 265 m, 3.1 °C and 34.7 respectively. Minke whales, fin whales, humpback whales, whitebeaked dolphins, killer whales, and porpoises were observed in waters with wide ranges of temperature and salinity, while blue whales and sperm whales were observed in waters with narrow ranges of these parameters. The lowest weighted average water temperature (0.3 °C) and salinity (34.4) were typical of humpback whale. Minke whale, fin whale, humpback whale and white-beaked dolphin had the largest overlap in their distribution with that of possible preys. Statistical analysis showed that priority preys for these cetaceans could be capelin and polar cod for the studied period. In addition, one of the possible preys for baleen whales was also macroplankton, and for the white-beaked dolphin — cod, blue whiting and redfishes.Practical significance: The results of this study can be used in studying the ecology of cetaceans in the Barents Sea, in assessing their impact on stocks of commercial fish species, as well as in ecosystem modeling.