Pelagic fishes

Pelagic fishes

5-Pelagic_fishes-(P)-Elderly_capelin_boat--(copyright-Hreidar_V)

An "elderly" capelin boat with a full hold

Photo: Hreiðar Valtysson

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Average catch of plagics from 2002 to 2011 by month and species

Source: Statistic Iceland, weight repor

The highest catches in Icelandic waters are from the few pelagic species. These fisheries are also characterized by great fluctuations, as the stock size and migration routes of these species are highly variable. The herring is probably the most important species historically. Three stocks occurred around Iceland: the Icelandic spring spawning, Icelandic summer spawning, and Atlanto-Scandian stocks. All of them collapsed in the late 1960´s, but the two last ones have fully recovered and now sustain considerable catches by Icelandic boats.

After the collapse of the herring stocks, the Icelandic boats turned to capelin, previously virtually unfished. This fishery rapidly grew to around 1 million tonnes annually, in some years as much as for all other species in Icelandic waters combined.

Three other pelagic fisheries have developed in Icelandic waters in recent years, all on international stocks. Icelandic fisheries for oceanic redfish began in 1989, blue whiting in 1997 and mackerel in 2006.

Another character of the pelagic species, as opposed to the demersal ones, is that their migration routes are much more extensive. The pelagic fisheries are consequently spread over a wider area. The capelin fisheries are conducted far north of Iceland at the start of the spawning migration and then follow the spawning migration around Iceland. The fishery for the Atlanto-Scandian herring is mostly in the Norwegian Sea, northeast and east of Iceland. This stock also used to provide a large part of the herring fisheries in Icelandic waters before 1967, but has not migrated into Icelandic waters after its collapse. The blue whiting fisheries are in international waters as well as within the Icelandic EEZ, east and southeast of Iceland. In the last couple of years, mackerel has made an appearance southwest of Iceland. Further west, over the Reykjanes Ridge, on the south western part of the EEZ and also outside it, considerable fisheries are conducted on oceanic redfish. The only commercial pelagic species that only occurs over the Icelandic continental shelf is the Icelandic summer spawning herring.

These fisheries are now exclusively carried out by vessels operating purse seines or pelagic trawls (herring and capelin) or only pelagic trawls (redfish, blue whiting and mackerel). Previously some quantities of herring were also fished with driftnets.

All these fisheries are seasonal; the capelin fishery is mostly from January to March during spawning migrations. Blue whiting fisheries begin at the end of the capelin season in spring but mackerel and Atlanto-Scandian herring fisheries are essentially conducted during the summer months. The rest of the year, from October to December, the pelagic fleet devotes to Icelandic summer spawning herring.

A large proportion of the landing of pelagic species is used for fish meal and oil production. However, an increasing share is used for human consumption. The oceanic redfish goes exclusively to human consumption. The pelagic fisheries are relatively clean, that is few other species are caught than the species targeted. However, if considerable bycatches occur, especially of juveniles, the areas can be closed for fishing.

Other pelagic species

5-Pelagic_fishes-(D)-Blue_fin_tuna--(copyright-Jon_B_H)

Blue-fin tuna

Illustration: Jón Baldur Hlíðberg

5-Pelagic_fishes-(D)-Sandeel--(copyright-Jon_B_H)

Sandeel

Illustration: Jón Baldur Hlíðberg

5-Pelagic_fishes-(D)-Pearlside--(copyright-Jon_B_H).jpg

Pearlside

Illustration: Jón Baldur Hlíðberg

A few other commercially important pelagic species occur in Icelandic waters. Horse mackerel (Trachurus trachurus) is not native in Icelandic waters but has in some years migrated there and some low amounts have been reported in catches. Blue-fin tuna (Thunnus thynnus) is also a migratory species in the southern extreme of the Icelandic EEZ. Pearlsides (Maurolicus mulleri) are among the smallest of the pelagic fishes. They occur regularly in Icelandic waters and have recently gained the attention of fishermen.

Sandeels (ammoditydae) and the great silver smelt are essentially benthopelagic fishes. The great silver smelt is found in the water column during the night, but close to the bottom during the day where they are fished in bottom trawls. Sandeels bury themselves into the sediment to escape predators. Some low amounts of sandeel have been fished in the past, but the fisheries were discontinued due to high bycatch of juveniles of other fish. Sandeels are of great ecological importance, as many other species depend on them as food. .

Four other fish species are also pelagic during a large part of their life, but we know them better from other habitats. These are the three salmonid species and the lumpsucker.

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