Ringed seals Phoca h~spida and harp seals P groenlandca were collected for dlet analysis along the ice edge in the Barents Sea to investigate possible niche overlap between these 2 seal species. The diet analysis is based on contents from stomachs and intestines. A resource availability survey was conducted concurrently based on an echo survey combined with demersal and pelagic trawling. Th.is survey showed that the potential prey biomass was dominated by pelagic crustaceans (99% of total

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... s)-principally Themisto ljbellula and Thyssanoessa spp. Despite the prevalence of these crustaceans both seal species showed a strong preference for fish of various species, which constituted only 1 " A of the biomass in the area. The most common fish in their diet was polar cod Boreogadussaida, which had a Manly's prey preference index of 0.87 for nnged seals and 0.42 for harp seals. Pianka's niche overlap index for the 2 seal species in thls area was 0.985, indicating an almost complete niche overlap. However, harp seals prey on significantly larger polar cod than ringed seals, and the larger cod were distributed in deeper water than smaller cod. Thus it appears that the 2 seal species exploit different fractions of the same resource.