Atlantic halibut

Northeast Atlantic halibut is a data-limited species. Available data indicates increasing catch levels, leading to concern for fishing pressure. There is also concern for biomass.Route 2 (data limited) scoring has been applied to this rating due to a lack of reference points for fishing pressure and biomass. Atlantic halibut is classed as Vulnerable in Europe (last assessed in 2013) and Near Threatened globally (last assessed in 2021). Atlantic halibut have a very low resilience to fishing pressure and it is likely that they are overfished in European waters.Catches of halibut by Norway have risen significantly, from 676 tonnes in 2002 to 3768 tonnes in 2023. A decline occurred between 2019 and 2020, with catches dropping from 3216 tonnes to 2405 tonnes, likely due to the Covid-19 pandemic. However, this quickly rose again to 3027 tonnes in 2021, and 3508 tonnes in 2022. The overall increase in catch is thought to reflect greater fishing effort in recent years, driven by the use of adapted longlines and more vessels entering the fishery. The combination of rising catch levels, and a lack of formal assessments and reference points for the fishery, leads to concern for fishing pressure.With no formal stock assessments of Atlantic halibut in Norwegian waters, biomass levels are unknown relative to sustainable reference points. Research indicates that stock levels fluctuate annually, with only populations in northern waters are considered in ‘good’ condition. Given the fragile state of the stock, and evidence from the wider Northeast Atlantic showing low biomass and recruitment failure, concern remains for stock biomass in Norway.

Management of Atlantic halibut in this region remains minimal. Without significant improvements in understanding stock status, effective management cannot be implemented. While a minimum landing size is in place, it is below maturity estimates.In the Northeast Atlantic, there is currently no widespread management measures for halibut. Without stock assessments, it is difficult to determine the status of the population or whether current fishing levels are sustainable, so appropriate management cannot be implemented.In Norway, there is a minimum landing size (MLS) of 84cm in place. However, halibut are estimated to reach maturity between 104-140cm. This means that many individuals are likely caught before reproducing, which can undermine stock stability. There is also a requirement to discard halibut over 200cm, but not for conservation purposes. Instead, it is due to the accumulation of contaminants making them unsafe to eat. Additional regulations include mesh size restrictions – 130mm north of 64˚N, and 120mm south of 64˚N. There is also a closed spawning season from 20 December to 20 April across the entire Norwegian economic zone.Despite these measures, effective management is hindered by a lack of biological information, particularly regarding population distribution, migration patterns, spawning behaviour, and other key characteristics.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 engagement

Gillnets in this area can encounter bycatch of marine mammals, elasmobranchs, and seabirds, including Endangered, Threatened, or Protected (ETP) species. However, impacts to the seafloor are minimal.Fixed nets, consisting of vertical net(s) suspended between a float line and a weighted ground line, have minimal impact on benthic habitats as they cause little disturbance to the seabed. However, they are associated with high levels of bycatch, including endangered, threatened, or protected (ETP) species.Globally, gillnet fisheries are recognised as posing the greatest threat to cetaceans, especially small coastal species. In this region, the harbour porpoise is the most frequently affected. Given the overlap between gillnet use and cetacean distribution, many species are vulnerable to entanglement. However, bycatch of larger whales in this ecoregion is less common, and individuals are often released alive.Harbour porpoises are 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 requirements for bycatch mitigation. Historically, annual bycatch rates of harbour porpoises in the Norwegian Sea were estimated at 2900 individuals, which exceeded both the sustainable anthropogenic removal threshold and the potential biological removal (PBR) limit. More recently, however, rates have declined to around 1600 individuals annually (2013-2018), which is below both of these thresholds. This reduction is thought to be linked to decreased fishing effort in the monkfish gillnet fishery. 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.Gillnet fisheries also pose risks to elasmobranchs, seals, and seabirds. Reported captures in this ecoregion include ray species, grey seals, harbour seals, common guillemots, and northern fulmars (listed as Vulnerable in Europe). While bird scarers have been shown to reduce seabird bycatch, their use in this region is undocumented. Furthermore, grey seal surveys have indicated a 50-60% decline in pup production between 2007 and 2015, thought to be driven in part by gillnet bycatch rates.Additional risks in the net fishery comes from gear loss, as nylon gillnets when lost at sea can continue fishing through ‘ghost fishing’ until they become tangled and sink or are removed. As all gear types require financial investment, there is incentive to maintain and retrieve lost nets and prevent ghost fishing.To improve monitoring and reporting of fishing activity, The Marine Conservation Society would like to see remote electronic monitoring (REM) with cameras implemented, used and enforced.