Swedish Agency for Marine and Water Management

The conflict between seals and fisheries along the Swedish coast is of serious concern. In the Baltic Sea, certain coastal fisheries, such as the herring gillnet fishery, are on the point of collapse because of this conflict. Damage caused by grey seals in this fishery is shown to be much more extensive than previously recognised. When seals raid the nets, a significant part of the catch is lost without trace. Seals pick out the fish from the nets without leaving any remains. In addition, the presence of seals around fishing gear scares fish away from the area, which can extend to a total loss of catch. The development of seal-safe fishing gear is crucial and is at present the only long lasting solution which would respect the needs of both seals and fishermen. However, development of new fishing gear is challenging and time-consuming and requires greater knowledge of both fish and seal behaviour. At present there is no suitable alternative fishing gear available for the gillnet fishery. If no solution is presented in the very near future, the only option for this fishery’s survival will be to reduce the seal population in areas subject to severe interference.

In the eel fishery on the west coast of Sweden, seal-safe fishing gear (eel fyke nets) has been developed and is already in use in the commercial fishery along the west coast. Trials with seal-safe fyke nets were carried out over many years both by professional fishermen and the Swedish Board of Fisheries. A fyke net which resisted attacks and retained a comparable fishing efficiency was developed.

In order to find a lasting solution to the problem, seal behaviour has been studied as well as the fyke nets' fishing efficiency. The issue of whether it is the eels or the by-caught species which attract harbour seals to attack fyke nets was raised. It was shown that harbour seals raiding fyke nets have a preference for eel. Certain harbour seals specialise in foraging at fyke nets and have developed different feeding preferences compared to other seals. Video observations of a fyke net baited with eel also showed that seals which have specialised in this behaviour may return repeatedly to attack the fishing gear. This is important knowledge which has been useful in the development of seal-safe fishing gear and in the management of harbour seals.