Skate, White

Rostroraja alba

Method of production — Caught at sea
Capture method — All applicable methods
Capture area — North East Atlantic (FAO 27)
Stock area — North East Atlantic
Stock detail

All Areas


Picture of Skate, White

Sustainability rating five info

Sustainability overview

The white skate are listed as “Critically Endangered” in the Northeast Atlantic and their populations are depleted. It is also an EU Prohibited Species in areas 2a, 3, 4, 6, 7, 8, 9 and 10 - meaning it cannot be targeted, retained, transhipped or landed, requiring them to be returned unharmed, where possible, to the sea. ICES recommend that there should be zero catches in the years 2018 and 2019. White skate was historically seen as a highly marketable skate as its wings are very large and thick. Due to its very low populations, white skate are automatically red-rated.

Biology

White skates belong to the Rajidae family which includes skates and rays. Rostroraja alba is a large-bodied skate that is known to have occurred in coastal waters of northern Europe. This species is long-lived and late maturing and is highly vulnerable to over-exploitation. Two spawning areas are known, both on the Irish west coast - Tralee Bay and inner Galway Bay - and these are the only known refuges for this species. The white skate is a large coastal and slope species growing to a maximum length of 200cm and weight of 77 kg. Size and age at maturity and maximum age are unknown.

Stock information

Criterion score: 1 info

Stock Area

North East Atlantic

Stock information

White skate is listed as a Critically Endangered on the IUCN Red List, is listed on the OSPAR List of Threatened and Declining Species and is protected on the UK’s Wildlife and Countryside Act (WG2017). Therefore, it is automatically deemed a red-rated species.

There are very little data collected for white skate as it is very rarely caught in trawl surveys and therefore, current surveys have been deemed as inappropriate for monitoring the stock status. The stock structure is unknown and no formal stock assessment have been conducted. However, there are sufficient data to conclude that the species is ‘severely depleted’ and near-extirpated from parts of the Celtic Seas and Biscay-Iberian ecoregions.

Management

Criterion score: 1 info

Since white skates are critically endangered and they are listed by OSPAR, it is illegal to retain them on board, to tranship or to land white skates in EU waters of ICES Subareas 6-10. When they are accidently caught, Council Regulation (EC) 2016/72 requires that they shall not be harmed and they should be promptly released. The white skate are legally protected in UK waters, as the species is listed on the Wildlife and Countryside Act. This is the highest protection possible under the EUs Common Fisheries Policy (CFP) and is a long-term conservation strategy aimed at very depleted and vulnerable species. ICES reviewed the listing of White Skate in 2010 and supports it’s inclusion on the Prohibited Species List.

Monitoring
Since populations of white skate are so low in trawl surveys, and little is known about the species, white skates may often go unrecorded as other species from its complex or accidently recorded incorrectly (as the code to record their capture RJA, is similar to the one for rays Rajidae, called RAJ) (WG2017). Due to all of these data quality issues, the existing surveys for white sharks are inappropriate for monitoring the status of this species.

Capture Information

Criterion score: 1 info

Since white skates are critically endangered and they are listed by OSPAR, it is illegal to retain them on board, to tranship or to land white skates in EU waters of ICES Subareas 6-10. When they are accidently caught, Council Regulation (EC) 2016/72 requires that they shall not be harmed and they should be promptly released. The white skate are legally protected in UK waters, as the species is listed on the Wildlife and Countryside Act. This is the highest protection possible under the EUs Common Fisheries Policy (CFP) and is a long-term conservation strategy aimed at very depleted and vulnerable species. ICES reviewed the listing of White Skate in 2010 and supports it’s inclusion on the Prohibited Species List.

Monitoring
Since populations of white skate are so low in trawl surveys, and little is known about the species, white skates may often go unrecorded as other species from its complex or accidently recorded incorrectly (as the code to record their capture RJA, is similar to the one for rays Rajidae, called RAJ) (WG2017). Due to all of these data quality issues, the existing surveys for white sharks are inappropriate for monitoring the status of this species.

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. White skate (Rostroraja alba) in the Northeast Atlantic. Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2016/2016/rja-nea.pdf

ICES. 2017. Report of the Working Group on Elasmobranchs (2017), 31 May-7 June 2017, Lisbon, Portugal. ICES CM 2017/ACOM:16. 1018 pp.

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