Atlantic catfish

Scientific: Anarhichas lupus. English: Wolffish, Atlantic wolffish, catfish, Atlantic catfish, seawolf. Icelandic: Steinbítur, sladdi. For more languages see the Marine Animal Dictionary.

Biology and distribution

The catfish is a large sized, rather long fish, usually around 50 to 60 cm long, but the largest individual caught in Icelandic waters measured at 125 cm. It is found all around Iceland, but is most common off Vestfirdir (West Fjords) peninsula in the west. It mostly occurs on mud or sand bottoms at depths between 40 to 200 m. It is found in European waters from Murmansk in the north to the English Channel in the south. It is also around the Faroe Islands, in southern Greenlandic waters and from Labrador to Cape Cod in North America.

The catfish has enormously strong jaws and teeth. In fact so strong that it has to be handled with caution by fishermen. However, these strong jaws are not put there by nature to bite fishermen but to crush shellfish and echinoderms as these are the main food of the catfish. It also feeds on fishes, such as capelin, when available.

Spawning takes place at 160-200 m depth off Vestfirdir peninsula in autumn and early winter, as opposed to most other fish that spawn in late winter and spring. Some spawning also occurs off the eastern part of Iceland. Unlike most other fish, the catfish guards the eggs until they hatch; usually it seems to be the role of the males to do that. During this time they lose their teeth. After the eggs hatch they migrate back to other areas around Iceland. Growth rate is slow but it can reach more than 20 years of age.

Catch and fishing methods

Most of the fisheries are conducted in March or April when the catfish is migrating back from the spawning grounds. These fisheries are mostly by longline. In other seasons of the year, the catfish is a prized bycatch in other longline, trawl or Danish seine fisheries. The catfish has for a long time been a valuable catch for the Icelandic fleet as well as for the English and German fleets when they conducted their fisheries around Iceland. The catch has been in the general range of 10,000 to 15,000 tonnes annually for the last 30 years. The fisheries are conducted all around Iceland, but the largest catches are off western and eastern Iceland.

Stock status (from the Marine Research institute)

Landings of Atlantic wolffish (Anarhichas lupus) in 2010 were 12 600 t, around 2 500 t less than in 2009. Recruitment indices are now at a historical low level and the index of fishable biomass is decreasing. According to the stock assessment, the fishable part of the stock has been decreasing since 2006 and further decline is foreseen, as recruitment to the fishable stock will be low in the coming years. MRI recommends a TAC according to the management strategy of Fmax or 7 500 t for the quota year 2011/12. In addition, the MRI recommends a continued closure of the major spawning area off West Iceland during the spawning and incubation season in autumn and winter.

Processing and markets

The majority of the Iceland catch is either iced at sea and then processed and frozen in Icelandic factories or, in equal amounts each, exported fresh in containers or by air. Compared to many other species, a relatively large share also goes to local consumption. In Iceland the catfish is considered one of the best fishes to wind-dry. The catfish is a popular food fish in Western Europe and is exported in roughly equal amounts to France, the United Kingdom, Germany or the Netherlands. The fillet is commonly eaten fried or battered in fish and chips.

References and further information

References: (Jónsson, 1982), (Gunnarsson, Hjörleifsson, Þórarinsson, & Marteinsdóttir, 2006), (Jónsson & Pálsson, 2006).

For full citation and further information on the main species in general see this page

Hreiðar Þór Valtýsson, University of Akureyri