Thornback ray

The population of thornback ray in the North Sea, Skagerrak, Kattegat, and Eastern English Channel is considered underfished and harvested sustainably.Stock assessments for thornback ray in this area are carried out every two years by the International Council for the Exploration of the Sea (ICES). The last assessment was released in 2025, with data up to 2024, following a benchmark in 2023. The stock assessment defines reference points for fishing pressure (F) and biomass (B). For fishing pressure, there is a target to keep F at or below Maximum Sustainable Yield (MSY). For biomass, there is no target. However, there is a trigger point (MSY Btrigger). Below this level, F should be reduced to allow the stock to increase. For this stock, both FMSY and MSY Btrigger are expressed as ratios rather than absolute values. Because BMSY is not defined, the Good Fish Guide applies its own definition of 1.4 x MSY Btrigger.The exploitable stock size has steadily improved with time. From 1989 to 2007, the stock remained below Blim (0.3), but it began to rise consistently from 2008 onwards. It surpassed MSY Btrigger (0.5) in 2013 and has remained above this threshold ever since. The estimated exploitable stock size for 2025 is 1.22, which is above MSY Btrigger (0.5) and the Good Fish Guide’s BMSY proxy (0.7). Therefore, this stock is considered underfished.Fishing pressure exceeded FMSY (1) between 1989 and 2006, peaking at 2.3 (1990-1992). Since then, fishing pressure has declined steadily, dropping below FMSY in 2007. From 2014 onwards, it has remained between 0.4 and 0.6, with the 2024 estimate at 0.46. As this is below FMSY, the stock is considered to be harvested sustainably.Retained catches of thornback ray from recreational fisheries are not quantified.ICES advises that when the Maximum Sustainable Yield (MSY) approach is applied, catches in 2026 and 2027 should not exceed 6081 and 6045 tonnes, respectively. This is an increase of 15% due to the increase in estimated stock size. Assuming discard rates remain at the recent three‑year average (2022–2024 = 19.1%), this corresponds to maximum landings of 4922 tonnes in 2026 and 4894 tonnes in 2027.

Thornback ray is a vulnerable species and management needs to be more precautionary. The joint TAC in place is not a suitable management method.There is no management plan in place for thornback ray in this area. Demersal elasmobranchs are usually caught as bycatch in the mixed demersal fisheries for roundfish and flatfish. Thornback ray is the main commercial skate species in the North Sea and eastern English Channel. However, there is no official Minimum Conservation Reference Size (MCRS) in place, so juveniles may also be landed.In 1999, a common Total Allowable Catch (TAC) for 'skates and rays' was first introduced. Five regional quotas are in place for the group of skates and rays, rather than for the individual species. This method of management has been deemed as unsuitable for protecting individual species, but species-specific quotas may also lead to discarding. In 2025, the TAC for skates and rays were set as follows:3168 tonnes for ICES areas 2.a and 487 tonnes for ICES area 3.a9430 tonnes for ICES areas 6.a, 6.b, 7a-c, and 7e-k 2688 tonnes for ICES area 7.d 5576 tonnes for ICES areas 8 and 9 (2024)Since 2013, thornback ray has been a prohibited species in ICES area 3a (Skagerrak and Kattegat) and must be released immediately and unharmed if accidentally caught.In North Sea waters, vessels larger than 15m, are only permitted to land a maximum of 25% of the catch (whole weight) as skates and rays.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.The EU and UK both have fishery management measures, which can include catch limits, population targets, and gear restrictions. However, compliance in the EU and UK has been inconsistent, with ongoing challenges in implementing some regulations. The goal of reaching Maximum Sustainable Yield (MSY) by 2020 was missed, with less than half of UK TACs in 2024 following ICES advice. In 2024, the EU and UK reaffirmed their commitment to sustainable fisheries by aligning management with scientific advice to gradually approach MSY. However, no new target date has been set for achieving MSY across all fisheries. The Landing Obligation (LO), an EU law retained by the UK post-Brexit, requires all quota fish to be landed, even if unwanted (over-quota or below minimum size). It aims to encourage more selective fishing methods, reduce bycatch, and improve catch reporting. However, compliance is poor, and accurate discard levels are hard to quantify with current monitoring programmes. The UK is in the process of replacing the LO with country-specific Catching Policies.The Marine Conservation Society views Remote Electronic Monitoring (REM) with cameras is one of the most cost-effective tools for providing reliable fisheries data and aiding informed management decisions. Fully monitored fisheries enhance collaboration, data accuracy, stock recovery, and reduce impacts on marine wildlife and habitats. However, the full potential of REM may only be achieved when it tracks fishing location and documents catch and bycatch, particularly where vulnerable species and habitats are at risk. As of January 2024, the EU is introducing a Remote Electronic Monitoring (REM) mandate for EU vessels, including CCTV cameras on vessels 18m or more that pose a potential risk of non-compliance, within the next 4 years. Across the UK, different approaches to REM are being taken and legislation is expected to be in place across all 4 countries within the next few years.The Fisheries Act (2020) requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) in the UK. 43 FMPs have been proposed and are at various stages of development and implementation, these should all be published by the end of 2028. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. It is also essential the UK governments define and adopt a standardised approach or model across the four nations to a universally defined FMP design, to ensure the consistence, quality and coherence of all the proposal FMPs.The Marine Conservation Society is keen to see publicly available Fishery Management Plans for all commercially exploited stocks, especially where stocks are depleted, that include:An overview of the fishery including current stock status, spatial coverage, current fishing methods and impactsTargets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidenceTimeframes for stock recoveryImproved data collection, transparency, and accountability, supported by technologies such as Remote Electronic Monitoring (REM)Consideration of wider environmental impacts of the fishery, including habitat impacts and minimising bycatchStakeholder engagementThe thornback ray is included in the Southern North Sea and Channel skates and rays FMP, coordinated by Defra. At the time of writing, it is too soon to know whether proposed management measures will be effective in managing the stock. For more information about this FMP and expected progress and timelines, see [https://www.gov.uk/government/publications/joint-fisheries-statement-jfs/list-of-fisheries-management-plans].

Gillnets in this area can encounter bycatch of non-target fish, mammals and birds, including ETP species. However, this gear type has minimal impact on the seabed.In 2024, most landings of thornback ray were from ‘all other bottom trawls’, including otter trawls (61%), followed by beam trawls (19%), other gear types (12%), and set nets (8%). The average discard rate from 2022–2024 was 19.1%. In 2024, this included 521 tonnes of dead discards, alongside an estimated 54% survival rate for individuals released from beam trawls.Elasmobranchs generally show relatively high survival rates because they lack swim bladders and are therefore less affected by changes in water pressure. Their thick, abrasive skin also provides additional protection. Inshore and coastal fisheries using trawls, longlines, gillnets, and tangle nets typically report low at-vessel mortality.Bycatch data for many UK and EU fisheries remains limited due to poor monitoring. However, fixed and drift nets can have high levels of bycatch, including endangered, threatened, and protected (ETP) species. This includes marine mammals, seabirds, and elasmobranchs.One notable bycatch species is the harbour porpoise, which is included on OSPAR’s List of Threatened and/or Declining Species and Habitats for the Greater North Sea and Celtic Seas, due to documented population declines and the ongoing threat of being bycaught. They are also considered a priority species under UK and EU law, under which there are explicit bycatch requirements. In 2023, bycatch of 389 harbour porpoises was reported in the Greater North Sea region. Acoustic Deterrent Devices (ADDs), such as pingers, have demonstrated effectiveness in reducing harbour porpoise bycatch in gillnets. However, their deployment is inconsistent, and their efficacy is unknown for other species.In UK waters, mesh size regulations for gill, trammel, and drift nets (maximum 110 mm) are intended to allow juvenile roundfish and flatfish to escape capture. However, due to the distinctive shape of skates and rays, even smaller individuals are difficult to avoid catching and rarely manage to escape. This poses a risk to reproductive capacity and long‑term stock stability.Contact between nets and the seabed is limited to very light contact from the footrope and minimal contact from the small anchors at each end. As the gear is not towed over the seabed there should be very little abrasion.Nylon nets, if lost, can continue to fish for several weeks before becoming tangled and bundled up, a phenomenon known as 'ghost fishing'. However, static nets, as with all gear, represent an investment by fishermen, and therefore there are incentives to avoid losing or damaging gear.To improve monitoring and reporting of fishing activity, MCS would like to see remote electronic monitoring (REM) with cameras implemented, used and enforced.