Tusk

Scientific: Brosme brosme. English: Tusk, torsk, cusk. Icelandic: Keila, brosma. For more languages see the Marine Animal Dictionary.

Biology and distribution

The tusk is a medium to large sized codfish, usually between 40 to 90 cm long, but the largest individual caught in Icelandic waters measured 120 cm. It is found all around Iceland, but is much rarer in the colder waters north and east of the country. Mostly it occurs on hard bottoms at depths between 20 to 1,000 m, older fish usually in the deeper waters. It is found in European waters from Murmansk in the north to Ireland in the south. It also occurs around the Faroe Islands, in southern Greenlandic waters and from Newfoundland to Cape Cod in North America.

It feeds on a variety of crustaceans and fishes, such as lobster, crabs, Norway pout and redfish. Spawning takes place along the south and southwest coasts, at a depth of 200 to 400 m, from April to July. It reaches sexual maturity at the age of 8 to 10 years, then 45 to 60 cm long. It can reach at least 20 years of age.

Catch and fishing methods

Total catches have been remarkably stable at around 6,000 tonnes annually since 1950. The Icelandic catches have been slightly more than half the total catch. The largest part of the foreign catch is taken by Faroese boats, still fishing in Icelandic waters. More than 95% of the catch is taken by longline as the tusk is usually found over hard bottom where trawlers cannot operate. The catch is evenly spread over the year.

Stock status (from the Marine Research institute)

Landings of tusk (Brosme brosme) from Icelandic waters were 8.300 t in 2009. Indices of fishable biomass in the groundfish survey increased between 2001 and 2005 but have not changed significantly since then. However, recruitment indices have de-creased by 50% at the same time. The tusk stock assessment is based on the Gadget model as recommended by the ICES benchmark meeting on the assessment of deepwater species (WKDEEP-2010). The MRI recommends that the catches be less than 6.000 t in the quota year 2010/2011, including catches of foreign vessels. This advice is based on F0.1=0.2. It is furthermore recommended that the closure of nursery areas off the southeast and south coasts is continued.

Processing and markets

The majority of the catch is salted but a considerable share is also frozen as fillets, and also dried. The largest market for tusk is in the Netherlands, where the frozen fillets are exported to. Italy comes second, with the salted tusk and Nigeria third, with the dried tusk. Spain is fourth in line, also with salted products.

References and further information

References: (Bergstad et al, 1998), (Magnúsdóttir et al, 1997) (Jónsson & Pálsson, 2006).

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

Hreiðar Þór Valtýsson, University of Akureyri