White skate
Common Name: White skate
Scientific Name: *Rostroraja alba
Description: The white skate (Rostroraja alba) is a species of skate in the family Rajidae. It is a benthic fish native to the coastal eastern Atlantic Ocean. Due to overfishing, it has been depleted or extirpated in many parts of its former range and is now endangered.
OSPAR Regions where it occurs: II, III, IV
OSPAR Regions where under threat and/or in decline: II, III, IV
What is the latest status of the white skate?
The status assessment describes the latest changes in distribution, abundance and range of the feature, as well as any changes in the threats and pressures impacting the feature. The status assessments are updated regularly and inform OSPAR’s consideration of the effectiveness of the measures and actions that have been adopted and implemented by Contracting Parties.
Key message
The most recent ICES advice (ICES 2019a) concerning white skate described the stock development over time as follows: “This species has disappeared from most areas of former habitat in the Northeast Atlantic. There are very few recent, authenticated records of white skate in this area; these isolated records are from the English Channel, western Irish waters, and Portuguese waters. According to historical literature it appears to have occurred more frequently in previous decades. ICES therefore considers this stock to be depleted.” No improvement in the status of this stock has been observed since the last OSPAR assessment (OSPAR 2010).
For more information please see our latest assessment
Population/Abundance
The white skate has disappeared from most areas of its former habitat in the Northeast Atlantic. There are very few recent, authenticated records of white skate in this region; these isolated records are from the English Channel, western Irish waters and Portuguese waters. According to historical literature, white skates appear to have occurred more frequently in previous decades. ICES therefore considers this stock to be depleted (ICES 2019a). ICES advises that, when the precautionary approach is applied, there should be zero catches in each of the years 2020–2023.
For more information please see our latest assessment
Threats and Impacts
The size and life history characteristics of this large demersal skate species render it particularly vulnerable to capture by fishing gears, which in combination with its population demography allow little capacity for it to withstand exploitation. White skates are likely to be caught as bycatch in multi-species trawl fisheries which operate along much of Europe’s continental shelf and upper slope, coinciding with this species habitat (Dulvy et al. 2006). The species is particularly vulnerable to being bycaught in comparatively shallow static net fisheries for crustaceans in one of its last refuges: Tralee Bay in southwest Ireland (Clarke et al. 2016).
While it is prohibited to retain this species if caught, white skates may not be reliably identified in catches at sea and discard survival is also unknown. While habitat degradation and prey availability may also have an effect on populations, such impacts are considered minor in comparison to that caused by fishing mortality.
For more information please see our latest assessment
Measures that address key pressures from human activities or conserve the species/habitat
Since 2010, the white skate has been listed as a prohibited species for EU waters in ICES subareas 6–10. There is an EU requirement that all discards of white skate in these subareas must be recorded by commercial fishing vessels (EU 2015). ICES previously advised that white skates be retained on the prohibited species list. Full species protection (to minimise potential mortality from recreational fisheries) does not apply across all of its OSPAR range, however.
The white skate is listed as ‘Critically Endangered’ on the IUCN Red List (Gibson et al. 2008, Nieto et al. 2015) and it is further protected in the UK by its Wildlife and Countryside Act.
For more information please see our latest assessment