Flapper skate

Dipturus intermedius

5: Avoid How we work out the ratings

What to check for

Location

North Sea and Skagerrak; Celtic Sea and West of Scotland: All areas

Technical location

7: Irish Sea, Porcupine Bank, English Channel, Bristol Channel, Celtic Seas, West and Southwest of Ireland, 6: Rockall, West of Scotland

Caught by

Bottom trawl (beam), Bottom trawl (otter), Net (gill or fixed)

Rating summary

It is prohibited to fish for, land, or retain blue and flapper skate in UK or EU waters. Very little is know about the stock, but both species are assessed as Critically Endangered by IUCN and are listed by OSPAR as a threatened and declining species. Therefore, they are automatically a red-rated species.

Rating last updated October 2023.

How we worked out this Rating

There is zero catch advice for both blue and flapper skate and it is prohibited to catch them across this area of Europe.

Blue skate and flapper skate are assessed together by ICES as the common skate or Dipterus spp. complex. Due to the lack of data collected for each species, there are no robust indicators to determine the population trends. There are no reference points for biomass, however, fishery surveys have shown an increased number of individuals caught. ICES may provide a stock-size indicator in the future. Both flapper and blue skate are assessed as Critically Endangered on the IUCN Red List.

Misidentification is common with all members of the genus in this area (blue skate, flapper skate, Norwegian skate, and longnosed skate). Taxonomic distinction between the two species is improving; however, some misidentification is still observed and reported landings are therefore not informative of species composition or catch.

There has been a marked decline in reported landings of Dipturus spp., the reasons for this are currently unclear to ICES. Current UK and EU regulations prohibit the fishing, retention on board, transshipping, or landing of blue skate and flapper skate. Both species have very low resilience to fishing pressure with minimum population doubling time of more than 14 years. ICES advises that when the precautionary approach is applied, there should be zero catch in each of the years 2023 and 2024.

Discarding is known to take place, but discard survival has not been estimated.

It is prohibited to catch blue and flapper skate across this area of Europe. Therefore, it is a critical fail on the Good Fish Guide.

There are a lack of reference points for the stock, which prevents the development of management plans. ICES advises that the collection of species-specific landings data should be introduced for more species of rays and skates to help inform on the status of these stocks. However, species-specific quotas may increase misreporting or discarding.

Current UK and EU regulations prohibit the fishing, retention on board, transshipping, or landing of the common skate complex (blue skate and flapper skate). This prohibition applies to UK and EU waters of ICES Division 2.a and subareas 3-4 and 6-10. The species’ are also on The UK List of Priority Species and Habitats and have been listed as priorities for conservation action under the UK Biodiversity Action Plan (UK BAP). The Plan aims to stabilise populations by minimising fishing mortality and legally protect it in at least 5 key areas. The Loch Sunart to the Sound of Jura Marine Conservation Order lists “common skate” as the designation feature of this MPA which should reduce fishing mortality and maintain habitat in an important area for the species.

Identification of skate and ray species at the point of sale is difficult as they are commercially valued for their wings and so the bodies are often discarded and the wings skinned. However, DNA analysis of skate wings on sale in the UK suggests that blue and flapper skate do not often reach the market. Landings for both flapper and blue skate are reported, however, they are often misidentified and recorded as Norwegian skate or longnosed skate.

The Skate Working Group and OSPAR highlight the need to build on and develop a greater understanding of the species’ current distributions and critical habitat to inform future management options. Additionally, flapper skate may be more vulnerable to overfishing which highlights the need to monitor and assess these two species separately.

Skates and rays caught in the Northwest waters (ICES subareas 6 and 7) and North Sea waters (ICES subareas 2a, 3a and 4) with all fishing gears, are exempt from the landing obligation, based on their high survivability rates. Any skates and rays that are discarded are required to be released immediately and below the sea surface.

Both the EU and UK have fishery management measures in place, which can include catch limits, targets for population sizes and fishing mortality, and controls on what fishing gear can be used and where. In the EU, compliance with regulations has been variable, and there are ongoing challenges with implementing some of them. There was a target for fishing to be at Maximum Sustainable Yield by 2020, but this was not achieved.

In the UK, it is too early to tell how effective management is, as the Fisheries Act only came into force in January 2021. The Act requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) but there are no details yet on how and when these will be developed. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. MCS is keen to see FMPs for all commercially exploited stocks, especially where stocks are depleted, that include:

Targets for fishing pressure and biomass, and additional management when those targets are not being met
Timeframes for stock recovery
Technologies such as Remote Electronic Monitoring (REM) to support data collection and improve transparency and accountability
Consideration of wider environmental impacts of the fishery

Blue and flapper skate can be caught using different fishing methods. As this species is a Fish to Avoid, capture method impacts have not been scored.

Blue and flapper skate are found in the Northeast Atlantic, from Iceland to the British Isles, they were formerly more widespread, including the Mediterranean Sea and North Africa, but the range is thought to be reduced due to fishing.

These species are not a target fishery but they can be taken as bycatch in fisheries catching roundfish and flatfish, the quantity of which is not known. Methods of capture can include, but are not limited to:

beam trawl
otter trawl
gill net
tangle net

All these methods may have bycatch of other vulnerable species, and trawling can have habitat impacts.

The Skate Working Group recommend that methods to reduce incidental catches are tested and implemented, including the removal of tickler chains in trawl fisheries.

References

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