Brill

Scophthalmus rhombus

Method of production — Caught at sea
Capture method — Gill or fixed net
Capture area — North East Atlantic (FAO 27)
Stock area — North Sea, Skagerrak and Kattegat, English Channel
Stock detail — 4, 3a, 7.d-e
Picture of Brill

Sustainability rating three info

Sustainability overview

Updated: July 2019.

Brill in these regions is mainly landed as bycatch in beam trawl and pulse beam trawl fisheries for plaice and sole, particularly in the North Sea. Scientific advice for this stock is based on a commercial biomass index used as an indicator of stock size. It’s likely that the stock is not at risk as ICES assesses that fishing pressure on the stock is below the FMSY proxy and spawning stock size is above MSY Btrigger proxy, but as no absolute values are known, the data limited scoring approach has been applied by MCS. Management of turbot and brill is under a combined species Total Allowable Catch (TAC) which prevents effective control of the single-species exploitation rates and could lead to high-grading (where lower value fish are discarded to make room for higher value fish) of the lower value species (brill). Whilst gill net fisheries can be very selective with regards to targeted fish species, they can encounter bycatch of vulnerable species including porpoise, sharks and seabirds. Bycatch of harbour porpoise in the North Sea is not considered to be a threat to the population, but localised depletion may be an issue in some areas.

Biology

Brill, like turbot, belongs to the family Scophthalmidae, a group of left-eyed flatfish (they lie on their right side and both eyes are on the left). Similarly, brill are distributed from southern Iceland, down the coast of western Europe, including the Baltic, and into the Mediterranean and Black Seas. Brill is a shallow-water fish (between 5 - 70m) mainly found in areas close inshore and even in estuaries. Mature fish tend to inhabit offshore areas and are rarely observed inshore. Brill prefer sandy bottoms, but are also found on gravel and muddy grounds. They can attain a length of 75cm, but usually no more than 55cm, and a weight of around 2.5kg for females (which are larger). Length at first maturity is 33-40cm, with females fully mature at about 4 years and 40cm. Maximum reported age is 6 years. They spawn in spring and summer. Larger brill (> 40cm) are primarily piscivorous. Small brill feed on small benthic fishes, sandeels, gobies, anchovy, and crabs; with increasing length the diet moves to small gadoids. Brill grows relatively fast and generally reaches a certain length faster (at younger ages) than flatfish, such as sole and plaice, in the same areas.

Stock information

Criterion score: 0.25 info

Stock Area

North Sea, Skagerrak and Kattegat, English Channel

Stock information

The stock was last assessed in 2019 and indicated that the stock was likely in a healthy state. The Surplus Production in Continuous Time (SPiCT) analysis suggests the fishing mortality is below, and the stock size it above, proxies of the MSY reference points. The biomass index has been gradually increasing over the time-series with moderate interannual variability but has been decreasing since 2015. ICES advises that when the precautionary approach is applied, catches should be no more than 2559 tonnes in each of the years 2020 and 2021 which represents a 19% reduction in advised catch from the previous two years, although only a minor reduction in terms of actual catch.

The stock is classed as data limited (category three) and the assessment is based on a commercial biomass index which may not accurately detect changes due to changing fishing patterns, including the use of pulse trawls. ICES note that the current surveys in this area are not designed for catching brill, especially large brill, and that a fisheries-independent survey that covered the entire distribution area of the stock, would improve the assessment. To address this issue in future assessments, a Dutch science-industry partnership initiated a new fisheries independent beam trawl survey for turbot and brill in 2019.

Management

Criterion score: 0.5 info

Management of brill in the North Sea is only partially effective. Brill here is a bycatch species in fisheries for plaice and sole and is classed as a bycatch species under the EU North Sea Multiannual Management Plan (NSMAP) for demersal stocks which came into effect in 2018. The NSMAP aims to ensure that exploitation of living marine biological resources restores and maintains populations of harvested species above levels which can produce the Maximum Sustainable Yield (MSY) and that the precautionary approach to fisheries management is applied. Bycatch stocks do not have specific targets under the NSMAP but are supposed to be managed in accordance with the best available scientific advice and the precautionary approach when no adequate scientific information is available. However, MCS has concerns that the NSMAP is not being adhered to for all bycatch stocks, especially where adequate scientific advice is available.

Brill in this area is managed under a combined total allowable catch (TAC) together with turbot. ICES have indicated that management of brill and turbot under a combined species TAC prevents effective control of the single-species exploitation rates which can result in high-grading and discarding of the lesser value species, in this case brill. Despite this, the total catches of brill have been within the scientifically recommended levels.

The stock classed as data limited (category three) and the assessment is based on a commercial biomass index which may not accurately detect changes due to changing fishing patterns, including the use of pulse trawls. ICES note that the current surveys in this area are not designed for catching brill, especially large brill, and that fisheries-independent survey that covered the entire distribution area of the stock, would improve the assessment. To address this issue in future assessments, a Dutch science-industry partnership initiated a new fisheries independent beam trawl survey for turbot and brill in 2019.

There is no official EU minimum conservation reference size (MCRS) for brill, although some regional authorities have applied their own. The most frequently applied is 30cm (e.g. in Belgium, Baltic, Cornwall), although even this size could be considered too small as brill do not mature until 33 -40cm for males and females respectively.

Brill has been under the landing obligation since the start of 2019 without exemptions.

Surveillance activities on fisheries for demersal stocks in the North Sea, Skagerrak and Kattegat and English Channel include the use of vessel monitoring systems (VMS) on vessels over 12m; direct observation by patrol vessels and aerial patrols; inspections of vessels, gear, catches at sea and on shore and requirements to record data in electronic logbooks (although vessels under 10m do not have to keep logbooks).

Capture Information

Criterion score: 0.5 info

Brill is mainly taken as a bycatch species in Dutch and Belgian beam trawl fisheries for plaice and sole in the North Sea. In 2018, about 63% of the catch was taken in beam trawl fisheries, 22% taken in otter trawl fisheries and 12% in trammel and gill net fisheries. The North Sea accounts for almost half of landings of brill from the northeast Atlantic. The English Channel is the second most productive area for brill.

Gillnets and fixed nets can be very size selective, but can bycatch species such as sharks, cetaceans and other marine mammals. Reports indicate that there is concern regarding the bycatch of cetaceans, particularly harbour porpoise, by gillnets. One of the areas of most concern is off the South West of England, where areas of higher gillnet fishing effort coincide with areas of larger harbour porpoise populations. However, these reports are based on highly uncertain data which cannot indicate the likelihood of bycatch either causing populations to decline or preventing populations from recovering. Progress on this issue is being made in some areas, with Defra leading work to improve monitoring and mitigation of cetacean bycatch (“Hauling Up Solutions”). A pilot project trialling self-reporting of bycatch is taking place in Cornwall, potentially backed up by electronic monitoring and VMS in time, and trialling the use of pingers and other mitigation technologies, which are known to deter harbour porpoise from entanglement in nets. MCS is pleased to see this progress, but notes that if catch rates of harbour porpoise do not show a decrease then scoring of this capture method may be affected. Because of gillnets’ durability (they are made of nylon), if lost, they can continue to fish for several weeks before becoming tangled and bundled up, a phenomenon known as ‘ghost fishing’. However, static nets, as with all gear, represent an investment by fishermen, and therefore there are incentives to avoid losing or damaging gear.

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

ASCOBANS, 2009. Conservation Plan for Harbour Porpoises in the North Sea as adopted at the 6th Meeting of the Parties to ASCOBANS, Bonn, Germany. 16 - 18 September 2009. Available at https://www.ascobans.org/sites/default/files/document/ASCOBANS_NorthSeaPlan_MOP6.pdf [Accessed on 31.07.2019].

Calderan, S. and Leaper, R., 2019. Review of harbour porpoise bycatch in UK waters and recommendations for management. January 2019, WWF. Available at https://www.wwf.org.uk/sites/default/files/2019-04/Review_of_harbour_porpoise_in_UK_waters_2019.pdf [Accessed on 31.07.2019].

EU, 2019. Technical measures regulation. EU 2019/1241. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1241 [Last accessed 13.09.2019].

EU, 2018. Regulation 2018/973 establishing a multiannual plan for demersal stocks in the North Sea and the fisheries exploiting those stocks. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32018R0973&from=EN [Accessed on 02.07.2019].

EU, 2018. Commission Delegated Regulation (EU) 2018/2035 of 18 October 2018 specifying details of implementation of the landing obligation for certain demersal fisheries in the North Sea for the period 2019-2021. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2018.327.01.0017.01.ENG [Last accessed 13.09.19].

ICES, 2019. Brill (Scophthalmus rhombus) in Subarea 4 and divisions 3.a and 7.d-e (North Sea, Skagerrak and Kattegat, English Channel). Available at http://ices.dk/sites/pub/Publication%20Reports/Advice/2019/2019/bll.27.3a47de.pdf [Last accessed 15.09.2019].

ICES, 2018. ICES Advice: Bycatch of small cetaceans and other marine animals - review of national reports under Council Regulation (EC) No. 812/2004 and other information. Published 11 September 2018. Available at https://www.ices.dk/sites/pub/Publication%20Reports/Advice/2018/2018/byc.eu.pdf [Accessed on 31.07.2019].

OSPAR, 2017. Intermediate Assessment 2017: Harbour Porpoise Bycatch. Available at https://oap.ospar.org/en/ospar-assessments/intermediate-assessment-2017/biodiversity-status/marine-mammals/harbour-porpoise-bycatch/ [Accessed on 31.07.2019].