Feeding Preferences of Harbour Seals (Phoca vitulina) Specialised in Raiding Fishing Gear

Abstract: The Swedish eel (Anguilla anguilla) fishery has suffered an increase both in damage to fishing gear and in catch losses caused by harbour seals (Phoca vitulina). Eel fyke nets, which are the principal type of fishing gear used, tend to incidentally catch species like cod (Gadus morhua), flounder (Platichthys flesus), and eelpout (Zoarces viviparus). These are species known to be important in the harbour seals’ diet. This raised the issue of whether it is the eels or the by-caught species, which attract harbour seals to attack fyke nets. To examine this question, trials were made with experimental fyke nets in three geographically separated areas within the Archipelago of Göteborg. In each area, fyke nets with two bags each were baited with eels in one bag and cod, flounder, or eelpout in the other. In all three areas, the harbour seals showed a clear preference for eels in the fyke nets. The results indicated that certain harbour seals specialise in foraging at fyke nets and have developed different feeding preferences compared to other seals. Knowledge about harbour seals’ behaviour around fishing gear is important and will be useful in the development of seal-safe fishing gear to prevent damage caused by harbour seals.

Key Words: Harbour seal, Phoca vitulina, eel, Anguilla anguilla, prey preference, foraging specialisation, fyke net, Kattegatt, Skagerrak, sealfisheries conflict

Document Type: Research article

DOI: 10.1578/AM.32.2.2006.152

Page Numbers: 152-156

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