Whiting

Merlangius merlangus

Method of production — Caught at sea
Capture method — Demersal otter trawl
Capture area — North East Atlantic (FAO 27)
Stock area — West Scotland
Stock detail

VIa


Picture of Whiting

Sustainability rating five info

Sustainability overview

The stock biomass is at an all time low with a large proportion of the annual catch discarded annually. Ask for fish from trawlers using approved methods to improve selectivity and reduce discards. Avoid eating fish below the size at which it matures, 30 cms, and during its breeding season, January to July.

Biology

Whelks are large marine gastropods, or snails, with strong, whitish shells. They are found from Iceland and northern Norway to the Bay of Biscay, and can be locally abundant around the UK except for the Isles of Scilly. They inhabit sandy and muddy areas, although they can be found on gravel and rocky surfaces, down to depths of 1,200 metres.

Whelks mate during autumn and winter and baby whelks emerge in the spring.

Whelks are carnivorous. They scavenge at depths between 3 - 600m. They have an exceptionally acute chemical sensory ability - which enables whelks to be commercially exploited in baited pots.

Whelks are a particularly vulnerable species because they are long-lived (up to about 15 years), mature late (5-7 years) and produce relatively low number of eggs. In addition, they aggregate together, lay their eggs on the seafloor and are easy to catch. Their exceptional acute sense makes it easy to attract them to whelk pots. These factors make them more susceptible to local overfishing, and once overfished, have a slow path to population recovery. This is further exacerbated when few whelks have had a chance to mature, which can lead to stock collapse e.g. in the Dutch Wadden Sea in the mid 1970as.

Stock information

Criterion score: 1 info

Stock Area

West Scotland

Stock information

The spawning-stock biomass (SSB) has been increasing since 2006 but remains very low compared to the historical estimates and is well below Blim. Fishing mortality (F) has declined continuously since around 2000 and is now very low. Recruitment is estimated to have been very low since 2002 but estimated to have increased in recent years.
ICES continues to advise that when the MSY approach is applied, there should be zero catch in each of the years 2017 and 2018.

Management

There are no specific management objectives known to ICES. Given the continued high discards and low Total Allowable Catch (TAC) this stock could become a major ‘choke species’ for the Nephrops fishery in the area in the context of the landing obligation. Choke species are fish species for which quotas are so limited relative to local or general abundance that the imposition of a landing obligation (LO) in a mixed fishery is liable to result in fishing vessels having to cease operations well before they have caught their main quota allocations. The TAC agreed for the fishery has been above catches advised by scientists for the past 10 years.

Capture Information

There is no directed fishery for whiting in this area. It is primarily taken as a bycatch by trawlers using 80-120 mm nets, fishing for nephrops and whitefish. Demersal trawling is associated with benthic impacts and high levels of bycatch. The highest proportion of effort is by relatively small meshed trawlers fishing for Nephrops, which are less selective for whitefish resulting in high levels of discarding. Measures to reduce discarding and improve the selectivity of the fishery such as the use of sorting grids and square-mesh panels are being adopted. The Scottish nephrops fleet have been actively working towards, and implementing, improved selectivity measures in small mesh trawls which are specifically aimed at reducing whitefish catches and discards, and are now operating on the West Coast with several approved gears. But despite the widespread use of large square mesh panels the proportion of fish discarded from this fishery remains high. The minimum landing size for whiting is 27cm, however fish over this size have been observed to be discarded. From a total catch of 1620 t in 2015, 1400 t (86%) were discards with Nephrops trawlers using small-meshes accounting for 77% of discards and 1% of landings. Discard rates in this fishery have in fact increased compared to in 2014 when 84% of a catch of 1113 t were discards with small-mesh trawlers accounting for 58% of discards and only 4% of landings.

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
Whiting

References

ICES Advice 2016, Book 5 http://www.ices.dk/sites/pub/Publication%20Reports/Advice/2016/2016/whg-scow.pdf