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 of Blonde Rays is unknown in this area. However, scientists believe that the population is declining. More information is required to better manage the fishery. There is no specific management plan for skates and rays in these waters. They are managed under a quota for many skates and rays but greater protection is needed. The landing obligation will be fully in place in 2019, which requires that all species with catch limits should be retained. However, skate and rays are excempt from the landing obligation due to their assumed high discard survival rates.

Beam trawling is also associated with discarding of unwanted fish and sometimes catch Endangered, Threatened and Protected 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: 0.75 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. Their abundance in this area increased substantially from 2010 to 2014 but subsequently has been decreasing and therefore, there is concern for biomass.

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. Landings data are still poor but are around that advised in scientific advice and therefore, there is no concern for fishing mortality.

Management

Criterion score: 0.75 info

There is no direct management plan for skates and rays in these waters. They are usually caught as bycatch in otter and beam trawl fisheries, which target finfish (including flatfish and gadoids).

Skates and rays are managed under five regional quotas (called TACs) which are applied to a group of species, rather than individual skate and ray species. This has been deemed as an unsuitable method for protecting individual species, but species-specific quotas may increase discarding.

The new North Sea Multi-Annual Plan (NSMAP), which came into effect July 2018, requires that several whitefish stocks (Cod, Haddock, Plaice, Saithe, Sole, Whiting, Anglerfish (Lophius piscatorius), Northern Prawn and Norway lobster)) are fished at MSY by 2020. However, there is a requirement to take into effect “the difficulty of fishing all stocks at MSY at the same time”. Precautionary management should be applied to stocks where no adequate scientific information is available (which includes some skate and ray species). The precautionary approach should ensure that exploitation is appropriate to restore and maintain the harvested species populations above levels, which can produce MSY. The NSMAP also requires that discards should be avoided and reduced where possible and that a good environmental status should be achieved by 2020. The effectiveness of the NSMAP is to be re-evaluated in 2023 and every five years thereafter (European Commission 2018c).

The European Commission have considered that skates and rays caught in the North Sea (including in ICES divisions 2a and 3a, and ICES subarea) with all fishing gears, should be exempt from the landing obligation, based on their assumed high survivability rates. However, Member States harvesting the stocks, should supply data to STECF to review the effectiveness of the exception and, by the 31 May each year produce a roadmap to increase survivability, fill in the data gaps identified by STECF and produce annual reports on the progress on survivability programmes. Any skates and rays that are discarded are required to be released immediately and below the sea surface (European Commission 2018a).

Other management methods are currently being considered at an EU level, fishing gear modifications, education, conservation measures (such as closed seasons during spawning times). Some protected areas have been designated in these waters but offshore areas are not sufficiently managed. There are no official minimum landing sizes except for some IFCAs, which, mandate a minimum landing size (40-45 cm disc width) in inshore waters in England and Wales.

Monitoring
ICES conduct assessments for most skate and ray species on a biennial basis. There are a lack of reference points for the stock, which prevents the development of management plans (Mangi et al. 2018). Data-limited approaches have been used (using some survey and landings data) but there are important information gaps. Projects including the Fisheries Science Partnership, Sustainable Management of Rays and Skates (SUMARiS), National Evaluation of Populations of Threatened and Uncertain Elasmobranch Stocks (NEPTUNE) have been collecting data to close these data gaps.

Enforcement
Surveillance legislation is underpinned by EU Law, which require that 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. There is direct management of fishing effort for vessels since 2003, which allocates effort in kW-days to vessels of >15 m. However, the inshore (smaller) fleets are generally not managed by effort to the same extent.

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 the blonde rays caught in beam trawls that are 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
The landing obligation will be fully implemented into our seas from 2019. Skates and rays will be exempt from the landing obligation, due to their higher likelihood of survival when discarded. Member states will be required to report on skate and ray catches and discards, and any improvements in selectivity programmes. It’s difficult to avoid catching skates and rays in nets and because of their peculiar shape and size; it’s also difficult for them to escape the net once captured. Therefore, selectivity programmes are in place reduce skate and rays catches and their survival rates. Discard rates of skates and rays vary dramatically (30 - 70%), depending on the marketability and management measures in place. For example, nearly all skates below 30 cm LT are discarded by English vessels (Silva et al., 2012). Bycatch can include juvenile skate as they can hatch from their egg cases at sizes of 10-20 cm LT and therefore, may be able to escape through the nets (Ellis et al. 2018). Their survival rates upon discarding is extremely variable, depending on the fishing and handling methods used to capture them. Elasmobranchs have the potential for relatively high survival rates because they do not have swim bladders (and thereby are not as impacted by pressure changes), they can have thick and abrasive skins and thorns (which protect them) and some have spiracles and a buccal-pump respiratory which excrete a mucus, which allows the skate or ray to ventilate and acquire oxygen when out of the water (Ellis et al. 2018). Inshore and coastal fisheries using trawls, longlines, gillnets and tangle nets generally show low at-vessel mortality. There are a lack of studies available on long-term skate and ray survival when they are released into the wild (Ellis et al. 2018).

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 how accustomed the seabed is to natural disturbance. Blonde rays inhabit offshore sandbanks and coastal shallows (Dedman et al. 2017). They occur over sandy, mud and gravel substrates.

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.

Ellis, J. R., Burt, G.J., Grilli, G., McCully Phillips, S.R., Catchpole, T.L., Maxwell, D.L. 2018. At-vessel mortality of skates (Rajidae) taken in coastal fisheries and evidence of longer-term survival. Journal of Fish Biology. 92, 1702-1719. doi:10.1111/jfb.13597

Mangi, S., Kupschus, S., Mackinson, S., Rodmell, D., Lee, A., Bourke, E., Rossiter, T., Masters, J., Hetherington, S., Catchpole, T. and Righton, D. 2018. Progress in designing and delivering effective fishing industry science data collection in the UK. Fish 00:1-21. https://doi.org/10.1111/faf.12279