Herring

Herring in the northern Irish Sea is overfished and subject to overfishing.Stock assessments are carried out annually by the International Council for the Exploration of the Sea (ICES). The most recent assessment was published in 2025 using data up to the same year. The next assessment is expected in 2026.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. Because BMSY is not defined, the Good Fish Guide applies its own definition of 1.4 x MSY BTrigger.In 2024 a serious issue with the assessment was identified, which resulted in an inter-benchmark and led to the 2023 advice for 2024 being re-issued.The spawning stock biomass (SSB) of herring in this area recovered from a low of around 7,512 tonnes in 2003 to 29,086t in 2010 and has fluctuated at high levels since. In 2025, the forecasted SSB was 9,358 tonnes, which is below MSY Btrigger (11,793 tonnes) and the GFG proxy for Bpa (9,573 tonnes), but above Blim (Blim: 7,352t). Therefore, there is concern for the stock level.Fishing mortality (F) has been increasing in recent years. In 2024, F (0.505) was above levels associated with Maximum Sustainable Yield (FMSY = 0.25) and Flim (0.45). Therefore, this stock is outside safe fishing limits and being overfished.Recruitment has fluctuated around the 10-year average since 2012, with a high recruitment in 2022 of 274,797 tonnes, but a lower recruitment of 173,916t in 2024.ICES advises that when the MSY approach is applies catches of herring in the Irish Sea should be no more than 2,935 tonnes in 2026. This fishery included herring from the Celtic sea stock which are below Blim and are set to have zero catch.

Some but not all appropriate relevant management measures and in place, enforced but are only partially effective.This stock is shared between the UK and Ireland, with the UK landing most catches. There is no precautionary or shared management plan in place for Northern Irish Sea, although there are aspirations to develop one.The primary concern with this fishery is the lack of a precautionary management plan.TACs are split between the UK and Ireland. Since 2013, TACs and catches have been in line with scientific advice up until 2024 when the TAC (7279 tonnes) was set above advice. However, this may have been due to the reissuing of the 2024 advice. Catches as estimated by ICES have been below or in line with the agreed annual TAC and advice since 2016. In 2025, the agreed TAC (5,223 tonnes) is was also above advice but that was also due to the reissuing of advice.Beyond TACs, harvesting is further regulated by an EU Minimum Landing Size (MLS) of 20 cm, exceeding the size at maturity (17 cm). Discards of unwanted (over quota or undersize) herring are negligible.The Pelagic Advisory Council (PleAC) has an aspiration to develop a long-term management strategy for this stock. It is known that juvenile Celtic Sea herring mix with the Irish Sea stock. As a result, this stock should be considered as part of a metapopulation. The consequence of this needs to be further evaluated for management and advice. Scientific advice is to avoid negative impacts on the spawning habitat of herring, unless the effects of these activities have been assessed and shown not to be detrimental to the stock. There has been an increase in marine anthropogenic activity, especially around marine renewables. The construction and development of wind farms, for example, results in disturbance to the seabed, as does aggregate extraction. Gravel is an essential habitat for spawning herring.Herring fishing in the Irish Sea faced several restrictions. Year-round closures applied along Ireland's east coast and within 12 nautical miles of Britain's west coast. The Mourne herring gillnet fishery had an exception to fish within the Irish closed box. The Douglas Bank spawning ground east of the Isle of Man was closed from 21 September to 15 November, and Irish boats were prohibited from fishing east of the Isle of Man. Additionally, national licensing still limits fishing in specific areas and seasons.Part of this stock, included in a separate Good Fish Guide rating, is independently certified to Marine Stewardship Council (MSC) standards.Fishing restrictions in the Irish Sea include year-round closures along Ireland's east coast and within 12 nautical miles of Britain’s west coast. The Mourne herring gillnet fishery is an exception, operating within the Irish closed box. The Douglas Bank spawning ground east of the Isle of Man is closed from 21 September to 15 November, with Irish boats prohibited from fishing in this area. National licensing also imposes additional seasonal and area restrictions.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, as 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 engagementAn Irish Sea Pelagic FMP has been proposed, coordinated DAERA that incorporates this stock. 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/collections/fisheries-management-plans#published-fmps]

Herring are caught by mid-water (pelagic) trawls in the northern Irish Sea. These trawlers do not make contact with the seabed and tend have very little bycatch of other species.Nearly all (94%) herring in the northern Irish Sea is caught by pelagic trawlers, primarily by the UK, with some catches by Ireland. Fishing occurs as herring migrate through the North Channel, along the Scottish coast, and near the Isle of Man, typically between June and November, depending on migratory behaviour.Pelagic herring fisheries are among the cleanest, with minimal bycatch, seabed disturbance, or discarding. A small number of vessels, often pair trawlers, dominate the catch, using advanced sonar and catch monitors to target herring with precision. Although pelagic trawling can occasionally lead to marine mammal bycatch, there have been no reports of Endangered, Threatened, or Protected (ETP) species being affected in this fishery. Mitigation measures, such as avoiding cetacean-prone areas and using acoustic pingers, further reduce the risk of interactions, which are considered low. Incidental bycatch of non-target species, like sprat, horse mackerel, or mackerel, is negligible.This fishery has no impact on the seabed, as pelagic trawling gear does not contact it, eliminating habitat risks. Juvenile herring are protected through year-round bans along Ireland's east coast and within 12 nautical miles of Britain’s west coast, though gillnets are permitted in the Irish closed box. The Douglas Bank spawning ground east of the Isle of Man is closed during spawning, and Irish boats are prohibited from fishing east of the Isle of Man.One potential ecological concern is the removal of herring, which serves as a key food source for predators like seabirds (gannets, guillemots, razorbills) and marine mammals (grey seals, harbour seals, and seasonal pilot whales).Herring recruitment tends to thrive in cooler temperatures, making the stock vulnerable to rising sea surface temperatures, which could negatively affect its long-term viability.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. To reduce the impacts of fishing on the marine environment we would like to see a just transition to the complete removal of bottom towed gear from offshore Marine Protected Areas designated to protect the seabed. We also want to see reduction and mitigation of environmental impacts including emissions and blue carbon habitat damage.