Ray, Cuckoo

Leucoraja naevus

Method of production — Caught at sea
Capture method — Demersal otter trawl
Capture area — North East Atlantic (FAO 27)
Stock area — North Sea and Skagerrak and Kattegat
Stock detail

4 and 3a


Picture of Ray, Cuckoo

Sustainability rating five info

Sustainability overview

The stock status of Cuckoo Ray in this area is unknown, abundance has been generally increasing with fluctuations.
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.

Both demersal otter trawls and beam trawls are associated with captures of ETP species and beam trawls can pose significant risks to the habitat. However, management can mitigate these risks e.g. area closures and is generally better in inshore waters.

Biology

Cuckoo rays belong to the Rajidae family which includes skates and rays. Cuckoo rays are a small to medium sized inshore and coastal shelf species attaining a maximum length of about 70cm. Males and females mature at between 54 and 59cm in length when approximately 4 years old. Maximum age 12 years.

Stock information

Criterion score: 0.75 info

Stock Area

North Sea and Skagerrak and Kattegat

Stock information

The state of the stock in these areas is unknown. Cuckoo ray abundance has been generally increasing with fluctuations in the population size. Populations are above the long-term average in the last seven years, though the stock size has recently decreased. It is unknown if the level of fishing is sustainable or not.

Scientists believe that landings should be no more than 116 tonnes in each of the years 2018 and 2019 but recorded landings were 170 tonnes in 2016.

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: 0.5 info

Cuckoo rays in this area are almost exclusively caught by bottom trawls. Cuckoo ray is an offshore species and forms an important component of mixed demersal fisheries, taken as bycatch in beam and otter trawls. Also targeted by sea anglers.

Bycatch
Bycatch in beam trawls from this area 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
Beam trawling is generally more targeted than demersal trawls. Whereas discards from beam and otter trawls are high. Otter trawls appear to catch more thornback rays than beam trawls and are not selective: discards are high among thornback rays <55 cm total length. 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. Around 2 out of 3 skates survive discarding for up to 45 days) though cuckoo rays are likely to have lower survival rates relative to other rays.

Habitat
Cuckoo ray are generally found on sand and gravel habitats. 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 the Ross worm (or sabellaria). Fishing occurs over a mixture of sandy 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. 2017. Cuckoo ray (Leucoraja naevus) in Subarea 4 and Division 3.a (North Sea, Skagerrak, and Kattegat). Published 6 October 2017. rjn.27.3a4 DOI: 10.17895/ices.pub.3183.

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