Ray, Cuckoo

Leucoraja naevus

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

6,7 and 8a,b,d


Picture of Ray, Cuckoo

Sustainability rating four info

Sustainability overview

The stock status of cuckoo ray in the Celtic Sea and west Scotland is estimated to be increasing. However, there is a major deficit of data on the amount of cuckoo rays that are being discarded in this area. Consequently, scientists have advised a decrease in their catches through a precautionary approach.

There is no specific management plan for skates and rays in these waters but there is some improved management in inshore waters. They are managed under a total allowable catch (TAC) for many skates and rays but greater protection is needed, for example through seasonal and/or area closures.

Both demersal otter trawls and beam trawls can occasionally catch endangered species and beam trawls can pose significant risks to the habitat. However, management can mitigate these risks and is management 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: 0.5 info

Stock Area

Celtic Sea and West of Scotland

Stock information

The stock status is unknown though there is an increasing trend in abundance. There is a major deficit in discard data and therefore, scientists advise that 2278 t were landed between 2015-2016 and that no more than 2734 tonnes should be taken in both years, 2017 and 2018.

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 ray is an offshore species and is usually a bycatch species taken almost exclusively in bottom trawls, which are fishing for hake, anglerfish and megrim.

Bycatch
Otter trawling is not very selective and therefore catches a variety of bycatch including soles, plaice, monkfish, John dory and other skates and rays. ETP species including Angelshark and Common skate (both critically endangered (IUCN)) which were depleted through fishing 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. A relatively high proportion of the catch is expected to be discarded. Fish are discarded if they are below the legal size, are not marketable or depending on the discard ban.

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. Cuckoo rays in this area are caught on a mixture of sediments, though habitats which are being fished by TR2 gears generally are impacted less than those areas fished by TR1 gears (which have larger mesh sizes compared to TR2 gears), as TR1 gears generally fish in deep water muddy habitat.

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. Cuckoo ray (Leucoraja naevus) in subareas 6 and 7 and divisions 8.ab and 8.d. Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2016/2016/rjn-678abd.pdf

Silva, J. F., Ellis, J. R. and Catchpole, T. L. (2012). Species composition of skates (Rajidae) in commercial fisheries around the British Isles, and their discarding patterns. Journal of Fish Biology, 80: 1678-1703.

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