Purse seine

Purse seine is the largest fishing gear used in Icelandic waters as regards weight and net opening. About two thirds of the total Icelandic catch has sometimes been fished with this single type of gear, the largest quantity being capelin which is mainly used for fishmeal and oil processing. Large amount of herring are also fished with purse seines while other pelagics are mostly fished by pelagic trawl. Lately the importance of the purse seine for pelagic has declined due to increasing use of pelagic trawls.

Purse seine is a circular netting fence, which is placed around a school of pelagic fish. Floaters keep the top edge of the net on the ocean surface while lead pieces weigh the lower edge down. A wire is threaded through metal hoops at the lower edge and on pulling this wire the net will be closed around the fish within. The circumference of the net is gradually decreased until the catch has been collected, often in a dense mass. The fish is then pumped on board.

The first recorded use of purse seines in Iceland was in 1904, although land seines had been used earlier. These early purse seines were used along with driftnets to catch herring in the first decades of the 20^th century. However, purse seines were heavy to operate and the fish schools needed to be seen from the surface before the gear could be deployed. Otherwise this cumbersome fishing gear would not catch anything. The first Icelandic purse seiners experimented with sonar in 1954 and powerblock in 1959 and by 1961 the whole purse seine fleet was equipped with these. The previous problems were, therefore, solved and purse seines quickly almost completely replaced the driftnetting for herring. Before these inventions herring catches reached a maximum of 200,000 tonnes per year, in 1966 the herring catches almost reached 800,000 tonnes. As might be expected the herring stocks collapsed soon after that due to overfishing, but also, partly, because of environmental changes. Pelagic fish species do not have much of a chance against purse seiners equipped with sonars and powerblocks in an uncontrolled fishery. Fortunately the fisheries for the herring and capelin, have been carefully managed after the collapse of the herring stocks in the late 1970´s.

Purse seines are used by large decked vessels, some of which are of similar size to large trawlers. The current two main types of purse seines are the herring and capelin seines. The main difference is the mesh size, which is 31,4 mm in herring seines and 21,0 mm in capelin seines. Cod fisheries were also conducted with seines from 1962 until 1976. These proved to be highly efficient but wasteful as the quality of the catch was low. These fisheries were, therefore, restricted within a few years after they started and were banned after 1976. Purse seines are used all around Iceland, following the spawning migrations of capelin from the waters north of Iceland to the southern coast or the feeding migrations of herring off the N and E coast and, more rarely, off the S and W coast.

References and further information

References: (Gunnarsson et al. 1998), (Kristjánsson 1985), (Þór 2003), (Þór 2005)

For full citation and further information on fishing gear see this page

Hörður Sævaldsson / Hreiðar Þór Valtýsson University of Akureyri