Tusk

Brosme brosme

Method of production — Caught at sea
Capture method — Longline
Capture area — North East Atlantic (FAO 27)
Stock area — Northeast Atlantic
Stock detail — IV, VII-IX, IIIa, Vb, VIa, and XIIb
Picture of Tusk

Sustainability rating three info

Sustainability overview

Many of the deepwater fisheries, including those for tusk, have limited data and there is little or no evidence that they are sustainable. Deepsea fish are highly vulnerable to over-exploitation and have a low resilience to fishing. Fishing effort on tusk impacts other deepwater species and habitat.

Biology

Tusk are found from depths of 20 m to 1000 m, but mainly inhabit deep water from 150 to 450 m. It spawns from April to July. It is regarded as the ‘odd fish out’ in the gadoid family (the group of fish that includes cod and haddock) because of its solitary and sedentary nature. It grows slowly and can attain a length of 120 cm and weight of 30 kg. Males and females mature at about 50 cm and 8 to 10 years old. Maximum age is about 20 years. Tusk’s life history traits are in line with other members of the gadoid family and suggest that it is less vulnerable to fishing mortality than typical deep-water species.

Stock information

Criterion score: 0 info

Stock Area

Northeast Atlantic

Stock information

Many of the deepwater fisheries, including those for tusk, have limited data and there is little or no evidence that they are sustainable. The state of the stock and fishery, relative to MSY reference points is unknown. The scientific advice for this stock is based on a standardized catch per unit effort (CPUE, the catch of fish in numbers or weight taken by a defined period of effort) series from the Norwegian longline fleet which shows an increasing or positive trend since 2004. Catches in all subareas were stable from 2002 to 2012, lower the last four years.

ICES advises that when the precautionary approach is applied, catches should be no more than 8984 tonnes in each of the years 2018 and 2019. Discarding is considered to be negligible.

Management

Criterion score: 0.75 info

There is no agreed precautionary management plan for tusk in the area.

Capture Information

Criterion score: 0.5 info

Tusk is taken in mixed fisheries with ling and as a bycatch species in longline, trawl and gillnet fisheries for a range of species, including cod. Longliners account for 90% of the catch of tusk in this area. It is mainly fished in depths in the range of 200-500 m. Fishing on the Mid-Atlantic Ridge is in the depth range 500-800m. Deep sea ecosystems are highly vulnerable and have a very low resilience, thus the impacts of any large scale removal of fish or abrasion of the seabed caused by fishing gear are likely to be severely detrimental with recovery slow, especially with regard to coldwater corals.

Alternatives

Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Basa, Tra, Catfish or Vietnamese River Cobbler
Bass, seabass (Farmed)
Bream, Gilthead (Farmed)
Cod, Atlantic Cod
Cod, Pacific Cod
Coley, Saithe
Haddock
Hake, Cape
Hake, European
Pollock, Alaska, Walleye
Sturgeon (Farmed)
Tilapia

References

ICES Advice 2017 http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/usk.27.3a45b6a7-912b.pdf