Diet of the harbour seal, Phoca vitulina, in the Hvaler area in 1990 and 1991, compared to the abundance of fish in the area
Working paper
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http://hdl.handle.net/11250/104996Utgivelsesdato
1992Metadata
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The harbour seal, Phoca vitulina, occurs in small groups along
the entire coast of Norway. It is thought to interact with the
commercial fisheries, both as predator and as final host for
parasitic nematodes infecting fishes. In order to describe the
diet and the feeding behaviour of the harbour seal, field-studies
were carried out in the Hvaler area in outer Oslofjord in 1990
and 1991. The studies include both analysis of harbour seal
faeces and trawling for information on prey-occurrence. In the
trawl-catches the species of Gadidae and Pleuronectidae were most
frequently found, with norway pout and plaice, respectively,
being the most important single species. Analysis of faeces
showed that the harbour seal feed opportunistic on some species
but not on all. The most important groups were the Gadidae,
Clupeidae and Ammodytidae, norway pout being the most important
single species. Benthic trawls, constructed to catch shrimps and
crayfish, were used, and Ammotydidae and Clupeidae were not found
in the trawls.