Ray, Blonde

Raja brachyura

Method of production — Caught at sea
Capture method — Beam trawl
Capture area — North East Atlantic (FAO 27)
Stock area — S North Sea and E English Channel
Stock detail

4c & 7d


Picture of Ray, Blonde

Sustainability rating five info

Sustainability overview

The stock status is unknown. However, scientists believe that the population is declining. More information is required to better manage the fishery. Blonde ray is potentially vulnerable to fishing because it matures at a large size and produces relatively few young. As a result, young blonde rays can be overfished before they have had a chance to reproduce

There is no specific management plan for skates and rays in these waters. They are managed under a total allowable catch (TAC) for many skates and rays but greater protection is needed.

Beam trawling is also associated with discarding of unwanted fish and sometimes catch ETP species but capture rates can be reduced with appropriate gear modifications. This fishing method can pose significant damage to the seafloor.

Biology

Blonde ray are an inshore species belonging to the Rajidae family of skates and rays. Maximum length is 110 cm. Length at maturity is 81-83 cm at ages 4-5 years. Found predominantly on sand and steep sandbanks and commonly occurs at depths from 14-146 m. Relatively few eggs are produced, meaning that few juveniles will be produced each year. In the English Channel, females with well-developed eggs occur from February to August. Eggs are laid in cases known as “mermaids purses”. Blonde ray breed in the Bristol Channel in April and May. Although it has a relatively broad geographical range, this species is most abundant from the British Isles to Portugal. Blonde ray is relatively common in inshore and shelf waters (down to about 150 m) in the English Channel and Irish Sea, Bristol Channel and St George’s Channel. Blonde rays are particularly vulnerable to depletion due to their late age at maturity, slow growth and they produce few young. Little is known about connectivity of blonde ray stocks, yet, connectivity is crucial for managing skates and rays and provides a long-term perspective of their population trends.

Stock information

Criterion score: 1 info

Stock Area

S North Sea and E English Channel

Stock information

No formal stock assessments have been undertaken for this species and so the state of the stock in this area is unknown. Scientists estimate that the stock is declining but it is difficult to estimate the population because Blonde Rays have a patchy distribution. In the Irish and Celtic Sea and North Sea, the Blonde Ray has a patchy distribution but can be locally abundant on particular grounds. The patchy distribution of this species makes it difficult for scientists to interpret survey data, and its tendency to form aggregations makes it vulnerable to localised depletion. Blonde ray is assessed as Near Threatened by IUCN.

Scientists advise that total allowable catches (TAC)s should be set at 195 tonnes for years 2018 and 2019. Catches that are brought back to port (called landings) have decreased since 2013 and were 147 tonnes in 2016. In the latter part of 2016, Dutch pulse fisheries showed that over 80% of the total catch of Blonde Ray in the southern North Sea were discarded.

The quality of landings data is still too poor to create stock assessments. More information is required on discard survival, catches in recreational fisheries and their survival rates to determine the true level of mortality caused by fishing.

Management

Criterion score: 0.75 info

There are no management plans or objectives for this species. Skates and rays are managed under five regional quotas (called TACs) applied to a group of species. This has been deemed as an unsuitable method for protecting individual species, but species-specific quotas may not be suitable because it may increase unnecessary discarding of skates and rays.

Other management methods are currently being considered at an EU level. Methods to avoid catching rays include closed areas and seasons and modifying fishing gear to observe their escape behaviour and design fishing gear accordingly. However, it is difficult to avoid catching rays in fishing gear (because of their peculiar shape) so fishing gear modifications have been suggested to improve the potential survival of rays so that they can be quickly and safely discarded.

There is no official minimum landing size for many skates and rays outside the 6 nautical mile limit in European waters. However, some inshore areas mandate a minimum landing size (40-45 cm disc width). There is direct management of fishing effort, depending on fishing gear, mesh size and area, however, this only applies to vessels of >15 m and therefore, inshore (generally smaller) fleets are generally not effort managed to the same extent. There are catch composition rules limit the percentage of skates that can be landed by demersal otter trawls (dependent on the mesh size of the net).

More information is needed on skate and ray catches, discard and survival rates. Landings data doesn’t tell scientists much about the health of the stock. The Fisheries Science Partnership project connects fishermen and scientists to fill in important knowledge gaps.

Surveillance legislation is underpinned by EU Law, and requires all vessels above 12m in length use vessel monitoring systems (VMS), and mandate at-sea and aerial surveillance and inspections of vessels, logbooks and sales documents.

Some protected areas have been designated in these waters but offshore areas are not sufficiently managed. Some of these MPAs are designated to protect rays such as the Offshore Overfalls MCZ which is designated partly to protect the undulate ray’s nursery areas. The inshore waters, such as the Isle of White SAC, ensure management, which may provide protection for various life stages e.g. undulate rays. Although the connectivity of these species is unknown and therefore, these waters need sufficient management and protection to prevent over-exploitation of these animals and their habitats.

Capture Information

Criterion score: 0.75 info

Blonde rays are normally caught with beam trawls in this area. The species is also targeted by sea anglers and the recreational catch thought to be substantial, but the quantities of retained catch are unknown.



Bycatch
Beam trawls in this area are not selective and catch relatively many more undersized rays than otter trawls or gill nets: nearly all Blonde Rays caught in beam trawls below 45cm total length are discarded. Common bycatch in bottom trawls include mixed crabs, urchins, lesser spotted dogfish, nursehound, Dragonet starry ray, smelt. Angelshark and common skate (critically endangered, IUCN) were depleted through incidental capture in trawls in this area. Invertebrates such as crabs and urchins are vulnerable to damage.

Discards
Because skate and rays are a peculiar shape and size, it is difficult for them to escape from fishing gear once caught. Therefore, other methods must be used to increase their likelihood for survival: skates and rays are generally a hardly species but their survival rate after discarding is extremely variable depending on fishing and handling methods: discard survival varied between 25%-100% in beam trawl surveys. However, in this specific area, discarding rates and survival is unknown. In the latter part of 2016, Dutch pulse fisheries showed that over 80% of the total catch of Blonde Ray in the southern North Sea were discarded.

Habitat
Bottom trawling has the potential to cause significant impact to habitat such as removing or destroying physical features and reducing biota and habitat complexity. Therefore, the recovery time of the seabed after trawling varies greatly and depends on the fishing gear, the substrate, intensity of the trawl and accustomed the seabed is to natural disturbance. Fishing occurs over a mixture of seafloor types. IFCAs ensure bottom trawling occurs in areas where there will be minimal damage to habitats such as mobile sands, however, in offshore areas, bottom trawling can occur over vulnerable habitats.

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. 2017f. Blonde ray (Raja brachyura) in divisions 4.c and 7.d (southern North Sea and eastern English Channel). Published 6 October 2017 rjh.27.4c7d DOI: 10.17895/ices.pub.3175. Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/rjh.27.4c7d.pdf.

Project Inshore MSC Pre-Assessment Database. 2013. North Sea and Channel (IVa VII d/e): Blonde ray: Demersal trawl (TR1: >100mm): Challenges. Available at: http://msc.solidproject.co.uk/inshore-uoc.aspx?id=8310&s=6268&a=

ICES. 2017a. Report of the Workshop to compile and refine catch and landings of elasmobranchs (WKSHARK3), 20-24 February 2017, Nantes, France . ICES CM 2017/ ACOM:38. 119 pp.

Marandel, F., Lorance, P., Andrello, M., Charrier, G., Le Cam, S., Lehuta, S. Trenkel, V.M. 2017. Insights from genetic and demographic connectivity for the management of rays and skates. Canadian Journal of Fisheries and Aquatic Sciences IN PRESS.

Scientific, Technical and Economic Committee for Fisheries (STECF) - 56th Plenary Meeting Report (PLEN-17-03); Publications Office of the European Union, Luxembourg.