Good Fish Guide
Method of production - Caught at sea
Capture method - All applicable methods
Capture area - North East Atlantic (FAO 27)
Stock area - Northeast Atlantic
Stock detail - IV, VII-IX, IIIa, Vb, VIa, and XIIb
Certification - None
Fish type - White round fish
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. Avoid eating.
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.
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 reference points is undefined. Catches in all subareas were stable from 2002 to 2012, lower in the last two years.
No specific management objectives known to ICES. It is considered incredibly difficult to manage a fishery for deepwater species sustainably; with the current poor data on the vast majority of deepsea fisheries, and poor understanding of the effects on the deepsea ecosystem and seabed, present knowledge is inadequate to provide sustainable advice. Due to the international nature of many of the deep sea fisheries on the high seas, compliance with any regulations can be low, and due to the difficulties in enforcement, there can be huge problems with Illegal, Unregulated and Unreported catches.
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. Many deepsea fisheries are experimental and are targeted with heavy bottom trawling gear, which can decimate seamounts and ocean ridge ecosystems. Lost gear, especially static gear such as gillnets, is likely to ghost fish for a very long time, as there are few currents in the deep sea to collapse or degrade the nets. Any bycatch in deepsea fisheries is likely to be of vulnerable species. Thus deepwater fisheries are considered unsustainable.
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.
ICES Advice 2015, Book 9 http://www.ices.dk/sites/pub/Publication%20Reports/Advice/2015/2015/usk-oth.pdf
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