Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen, Norway

摘要: Complete gastro-intestinal tracts (GITs) from 267 ringed seals five different locations in Spitsbergen were collected during spring of the years 2002 –2004. Diet was assessed based on hard part remains prey. Invertebrates constituted ,2% all prey (relative frequency, Ni). Fish otoliths found seals; 1.7, 34.3, and 64.0% recovered stomach, small large intestines, respectively, emphasizing importance analysing whole GIT, not only stomach. Otoliths stomachs intestines with minimal signs erosion measured to back-calculate pre-ingested size biomass. Based polar cod (Boreogadus saida) (n ¼ 7007), fed fish length range 44.4 – 229.2 mm, primarily consuming youngest year classes. Adult females ate smaller more often than adult males or juveniles. Polar dominated diet, a frequency occurrence (FO) 100%, Ni 71.9%, biomass contribution 77.2%. The taxon Stichaeidae second most frequent type (FO 55.6%) followed by Cottidae 35.6%). diet one locality markedly differed others, greater species diversity, low (15%), dominance (Ni 67%). Location sampling, as well sex age seals, had significant influences seal spring.