Feeding habits of harp (&lt;i&gt;Phoca groenlandica&lt;/i&gt;) and hooded seals (&lt;i&gt;Cystophora cristata&lt;/i&gt;) during late winter, spring and early summer in the Greenland Sea

Vladimir Potelev,Tore Haug,Kjell Tormod Nilssen,Vladislav Svetochev

doi:10.7557/3.2970

Abstract

Diet data were collected in the Greenland Sea pack ice (the West Ice) from March to June from harp seals (Phoca groenlandica) in 1987, 1990-1992 and 1997, and from hooded seals (Cystophora cristata) in 1992 and 1994, during Soviet Russian commercial sealing and on Norwegian scientific expeditions. The majority of both harp and hooded seal stomachs were empty but intestinal contents were found in most of the seals. The harp seal diet was totally dominated by the amphipods Parathemisto sp. and Gammarus sp., but krlll (Thysanoessa sp.) and polar cod (Boreogadus saida) were also eaten quite frequently. Hooded seals had been feeding mainly on the squid Gonatus fabricii, which was found most frequently in the intestines, but which also dominated in the few stomachs with contents. Polar cod also occurred quite frequently in the hooded seal diet, while crustaceans, such as amphipods and krill, occurred only sporadically.

Highlights

Three stocks of harp seals (Pho ca groenlandica) (Fig. 1), and two stocks of hooded seals (Cystophora cristata), inhabit the North Atlantic Ocean
Studies based on mass transfer efficiency between mothers and pups and diving records of lactating females suggest that harp seal females have to consume some food during the lactation period (Lydersen and Kovacs 1993)
Stomach contents were found in approximately 30% of the lactating harp seals in this study, confirming that females feed during the lactation period

Summary

Introduction

Three stocks of harp seals (Pho ca groenlandica) (Fig. 1), and two stocks of hooded seals (Cystophora cristata), inhabit the North Atlantic Ocean. The harp seal is the most abundant seal species in the North Atlantic, but the stocks of hooded seals are large. All stocks of both species have been subject to exploitation and are managed separately. Their role as top predators is considered important in a management context, and a provisional attempt to estimate the consumption by harp seals off Newfoundland was made by Stenson et al (1997). In order to provide more data on the feeding habits of harp and hooded seals in the Greenland Sea, Norwegian studies of weaned pups of both species were initiated in 1995 (Haug et al this volume).

MATERIAL AND METHODS

Findings

DISCUSSION