Ray, Undulate

Raja undulata

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

7b,j


Picture of Ray, Undulate

Sustainability rating five info

Sustainability overview

Undulate rays were a prohibited species for this area between 2009 and 2014. Since 2015, no directed fishery has been allowed to take place under EU regulations. ICES advises that there should be zero catches for this stock in years 2019 and 2020.

The stock status of Undulate rays in this area is unknown, though the stock size indicator shows that the population size is very low. In addition, another proxy for abundance shows that the number tagged of undulate rays in the sport fishery per year, has declined since the mid-1970s.

The EU had designated the Undulate ray as a Prohibited Species for commercial fishing vessels in ICES areas 6, 7, 8, 9 and 10. This meant fishermen were prohibited from targeting, retaining, transhipping or landing the species in these areas. Tralee Bay is voluntarily closed to commercial fishing to protect regionally important elasmobranchs including the undulate ray. The undulate ray is a key marine species in the UK Biodiversity Action Plan (UK BAP). Undulate rays are managed under a minimum landing length, a 3 month ban on their landings during their breeding season, a code of good practice with stakeholders and requirements on how they are landed. The code of practice should be followed by fishermen to the greatest degree possible but greater enforcement is needed in fisheries to ensure these bans are effective: it has been recorded that enforcing a ban on tangle netting in Tralee Bay in Ireland is difficult and therefore, the species are at risk of overfishing.

Biology

Undulate rays belong to the Rajidae family, which includes most of the skates and rays commonly found in British waters, and sold at fishmongers. The undulate ray is a medium sized shelf species growing to a maximum length of 100 cm and weight of 10 kg. The species has a maximum age of 20 years with size and age at maturity estimated at 75 cm and 9 years for females and 73 cm and 7.5 years for males. Eggs are laid from March to September. Undulate rays are at the northern edge of their range in UK waters. They form discrete populations isolated from other stocks, for example, on the southwest coast of Ireland, with occasional records in the English Channel. They are also present along the south coast of England.

Stock information

Criterion score: 1 info

Stock Area

Celtic Sea and west of Scotland

Stock information

Undulate rays were a prohibited species for this area between 2009 and 2014. Since 2015, no directed fishery has been allowed to take place under EU regulations. ICES advises that there should be zero catches for this stock in years 2019 and 2020.

There are no reference points to determine the undulate rays’ overfished status. There is no stock size indicator, though the population size is very low. The only proxy for abundance is the number of undulate rays tagged in the sport fishery per year, which shows a decline since the mid-1970s.

Management

Criterion score: 1 info

The EU had designated the undulate ray as a Prohibited Species for commercial fishing vessels in ICES areas 6, 7, 8, 9 and 10. This meant fishermen were prohibited from targeting, retaining, transhipping or landing the species in these areas. Tralee Bay has a voluntarily closure for commercial fishing, to protect regionally important elasmobranchs including the undulate ray. The undulate ray is a key marine species in the UK Biodiversity Action Plan (UK BAP). Undulate rays are managed under a minimum landing length, a 3 month ban on their landings during their breeding season, a code of good practice with stakeholders and requirements on how they are landed. The code of practice should be followed by fishermen to the greatest degree possible but greater enforcement is needed in fisheries to ensure these bans are effective: it has been observed that enforcing a ban on tangle netting in Tralee Bay in Ireland is difficult and therefore, the species are at risk of overfishing.

It is prohibited to fish using tangle nets in Tralee Bay and its surroundings. However, this has been difficult to enforce. More management is needed to reduce their catch as bycatch and their survivability when caught, particularly in otter trawls.

Monitoring
There are limited landings and discard data for the species, therefore fishing mortality is unknown. Some fishery-independent surveys have taken place. General trawl surveys conducted in the region are unlikely to provide accurate abundance estimates of undulate rays because they have a very isolated distribution in this area, concentrated in Tralee Bay. Tagging studies were conducted between the 1970s and 2000s, which showed a declining trend in abundance. Their populations are unlikely to have increased considerably since this time given the life history of the undulate ray.

Capture Information

Criterion score: 1 info

The Undulate Ray in this area has a very local distribution, mainly in Tralee Bay on the Southwest Irish coast. Undulate rays are not targeted in this fishery. It is caught in significant amounts as bycatch in tangle net fisheries which target spiny lobster or near-shore mixed-trawl fisheries. To mitigate this, there is a prohibition on tangle-netting in and around Tralee Bay and its vicinity, but it is difficult to enforce. Further measures are required to reduce the impact on undulate rays in this area. In this area, scientists advise that all Undulate Rays in this caught area should be released. Under current EU legislation, where a directed fishery for skates takes place, a mesh size in the cod-end of no less than 28cm is required and not less than 22cm in the rest of the trawl.

Discards
Tag-recapture studies suggest that when undulate rays are caught by tangle net, they were in better condition than when they were caught by otter trawl. Undulate ray survival may be higher than that for other skate species: their vigour (an indicator of health) was also found to be higher than that for other skate species, when caught using trawl and tangle nets (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.

Undulate rays are generally found over sandy substrates (Barnes 2008).

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

Marine Management Organisation. 2017. Undulate Ray commercial bycatch. Available at: https://www.gov.uk/government/publications/undulate-ray-commercial-bycatch;
ICES. 2018. Undulate ray (Raja undulata) in divisions 7.b and 7.j (west and southwest of Ireland) . Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2018/2018/rju.27.7bj.pdf. Published 5 October 2018

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;
Shark Trust; 2010. An Illustrated Compendium of Sharks, Skates, Rays and Chimaera. Undulate Ray. Available at: https://www.sharktrust.org/shared/downloads/id_guides/undulate_ray_st_id_guide.pdf

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