Turbot (Caught at sea)

Psetta maxima

Method of production — Caught at sea
Capture method — Trap
Capture area — North East Atlantic (FAO 27)
Stock area — North Sea
Stock detail

IV


Picture of Turbot (Caught at sea)

Sustainability rating two info

Sustainability overview

Turbot is taken as a valuable bycatch in flatfish fisheries for plaice and sole. There is a general absence of stock data for turbot, insufficient to evaluate stock status. Available information suggests the North Sea stock biomass, where 90% of the catches in the Northeast Atlantic are taken, has decreased and in recent years has stabilised at a low level. Avoid eating wild-caught turbot during its spawning season, April to August, and below the size at which it matures, 30 cms.

Biology

Turbot belongs to a small family of left-eyed flatfish (both eyes on the left of the body), known collectively as the Scophthalmidae. This family of fish is confined to the north Atlantic basin and includes megrim and brill. Turbot becomes sexually mature at an age of 3-5 years and in most parts of its range spawns in April to August, females each producing up to 10-15 million eggs. Turbot is one of the fastest growing flatfish, with females growing faster than males, in the North Sea reaching a length of around 30 cm (males) and 35 cm (females) in about 3 years. In the Baltic Sea growth is slower, and the males become sexually mature at a length of 15 cm, the females at 20 cm. By 10 years of age growth rates have reduced to 1-2 cm per year for females and less than 1 cm per year for males. Consequently, females are larger than males at any given age. Turbot can attain a length of 1m and a weight of 25 kg. Maximum reported age 25 years. For some reason males are generally more abundant than females. Turbot is distributed from Iceland, down the coast of western Europe and into the Mediterranean. Turbot are typically found at a depth range of 10 to 70 m, on sandy, rocky or mixed bottoms. It is one of the few marine fish species that inhabits brackish waters. Turbot appears to be a rather sedentary species, although some adult migration may occur.

Stock information

Criterion score: 0 info

Stock Area

North Sea

Stock information

Fishing mortality (F) is estimated to have decreased since the mid-1990s and has been stable for the past ten years. Spawning stock biomass (SSB) has increased since the late 1990s. ICES advises that when the precautionary approach is applied, catches should be no more than 4952 tonnes in each of the years 2018 and 2019. If discard rates do not change from 2016, this implies landings of no more than 4159 tonnes (1925 t in 2016 and 2017; 2,406t in 2015; 2,978t in 2014). Discard rates estimated at 16%.

Management

Criterion score: 0.75 info

No specific management objectives are known to ICES. An EU total allowable catch (TAC) is set for EU waters of ICES Division IIa and Subarea IV together with brill. ICES suggests TACs may not be an appropriate management tool for bycatch species such as turbot. Also a combined species TAC prevents effective control of single species exploitation rates, leading to overexploitation of either species. Currently, the catches consist predominantly of immature fish, which is having a negative impact on the potential yield from the stock. As turbot is a fast-growing species, reduction in the exploitation on younger ages would lead to an increase in maximum sustainable yield. No official minimum landing size has been set, but Belgian and Dutch producer organizations have adopted voluntary minimum landing sizes, although this still leads to a large proportion of immature fish being caught.

Capture Information

Criterion score: 0 info

Turbot is a valuable bycatch species in beam (62%) and otter (23%) trawl and gillnet (13%) fisheries for flatfish (plaice and sole) and demersal species. Quota restrictions apply only to the North Sea, where aroud 90% of the catches in the Northeast Atlantic are taken, and where they are included in a quota with brill. There is no official EU minimum landing size, although Minimum Landing Sizes (MLS) have been introduced by different authorities. The most frequently applied MLS is 30cm (e.g. Belgium, Baltic, Cornwall).

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.

Dab
Halibut, Atlantic (Farmed)
Halibut, Pacific
Megrim
Plaice
Sole, Dover sole, Common sole
Sole, Lemon
Turbot (Caught at sea)
Turbot (Farmed)

References

ICES Advice 2017 http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/tur.27.4_replaced.pdf (Accessed December 2017)