Field studies of harp seal (Phoca Groenlandica) distribution and feeding ecology in the Barents Sea in september 1990

The harp seal Phoca groenlandica is the most abundant seal species in the Barents Sea, and it may be a significant predator on other marine resources in this area. In order to evaluate the ecological role of harp seals, field studies, including both analysis of harp seal stomach contents and concurrent estimates of prey abundance, were carried out in the Barents Sea during August/September 1990. It appeared that, at this time of the year, the harp seals were confined to the northmost areas of this sea, either close to or within the pack ice belt. Trawl surveys revealed that the most abundant food resources in sea surface layers in areas close to the pack ice belt were the amphipod Parathemisto libellula and krill Thysanoessa spp. The fish fauna is poor, and occurs mainly near the bottom. Numerically, capelin Mallotus villosus and polar cod Boreogadus saida dominated, but also long rough dab Hippoglossoides platessoides, Greenland halibut Reinhardtius hippoglossoides, snailfish Liparis fabricii and Atlantic poacher Leptagonus decagonus occured quite frequently. The amphipod P. libellula is the prey item found most often in seal stomachs and it also contributed most to the biomass of the seal diet. A few fish, in particular polar cod and Greenland halibut, were also found in the seal stomachs.