Ray, Shagreen

Leucoraja fullonica

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

6 and 7


Picture of Ray, Shagreen

Sustainability rating five info

Sustainability overview

The stock status is unknown. There are some positive signs of population growth.

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. Stronger management is required e.g. closed areas.

Both demersal otter trawls and beam trawls are associated with occasional captures of endangered species. However, management can mitigate these risks and is generally better in inshore waters.

Biology

Shagreen rays belong to the Rajidae family which includes skates and rays. The shagreen ray is a medium sized species growing to a maximum length of 120 cm. Males and females mature from 56 to 85 cm in length. Age at maturity and maximum age is unknown.

Stock information

Criterion score: 0.75 info

Stock Area

Celtic Sea and West of Scotland

Stock information

The stock status of Shagreen Ray in this area is unknown because of the lack of species-specific landings data, survey coverage and its low appearance in scientific surveys. However, data from a French on-board observation programme between 2007 and 2015 in the Celtic Sea show that the population is rather stable and was at its highest level in 2015.

Scientists advise that landings should be 210t in 2017 and 2018 seasons. Landings were around 196 tonnes in 2015 and have been steadily decreasing over recent years.

The species would benefit from additional measures to regulate exploitation of the stock such as seasonal and/or area closures.

Discarding levels and fishing mortality is unknown.

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 but more management and protection is required to prevent over-exploitation of these animals and their habitats.

Capture Information

Criterion score: 0.75 info

Shagreen Rays are mainly caught as bycatch in bottom trawl fisheries which target hake, anglerfish and megrim. Bycatch
Otter trawls are not a very selective gear.

Bycatch
The catch may include a large variety of species such as various soles, plaice, monkfish, haddock, cod, John Dory, red gurnard, horse mackerel, boar fish and grey gurnard, skates, rays and starry smooth-hound.

ETP species can occasionally be caught such as Common Skate and Spurdog in offshore otter trawl fisheries but it is illegal to land these species.

Discards
Since 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. As part of the cod-recovery plan trawlers have Square Mesh Panels (SMPs) which allows bycatch species to escape the nets including dogfish. Dogfish have really rough skin which harms other species in the net. By allowing them to escape, it means that skates and rays are more likely to be discarded alive. Discards of other species may include undersized or unmarketable fish or because they are choke species. Discards rates vary dramatically (30 - 70%)

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 e.g. sandy, muds, gravel. In beam trawls, VMS shows the location of trawling. IFCAs ensure bottom trawling occurs in areas where there will be minimal damage to habitats e.g. by requesting that otter trawls avoid vulnerable features such as ross worm (or sabellaria), however, in offshore areas, bottom trawling can occur over a variety of 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 2016. Shagreen ray (Leucoraja fullonica) in subareas 6-7 (West of Scotland, southern Celtic Seas, English Channel). Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2016/2016/rjf-celt.pdf