Herring

The North Sea Autumn Spawning herring population is just above target levels however the stock is being overfished.Stock assessments are carried out annually by the International Council for the Exploration of the Sea (ICES). The most recent stock assessment was published in 2025 using data up to 2024. 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.The herring stock in the North Sea has been declining since 2016, when it was around 2.2 million tonnes. This is because reproductive rates (aka recruitment) have been low. The predicted spawning stock biomass (SSB) for 2025 is 1,239,052 tonnes, remaining above the biomass trigger point (MSY Btrigger, 1,100,000 tonnes), but was below the GFG proxy for MSY (1,540,000 tonnes). Therefore, the stock is in a fully fished state and continued decline would be cause for concern.Fishing mortality (F) has been below current estimates of FMSY (0.23) since 1996. However, in 2024 F was 0.29, this is above FMSY and 1.1 FMSY (0.25), but below the proxy for Flim (0.32). Therefore, there is concern for fishing pressure and the stock is being overfished.ICES advises that when the MSY approach is applied, catches in 2026 should be no more than 287,772 tonnes. This is a 30% decrease from the advice for 2025, owing to the decline in biomass.Projections suggest that the SSB in 2026 will be below MSY Btrigger. ICES notes that setting catch limits in line with the MSY advice rule, in combination with low recruitment, may keep the stock above MSY Btrigger in the short to medium term.

Some appropriate management measures are in place for North Sea and English Channel herring. Historically, catches have been higher than scientific recommendations, although they have recently started to decrease.North Sea Autumn Spawning (NSAS) herring is caught by the EU, UK and Norway. There is no shared management plan, but there is a joint agreement between the three parties on setting catch limits (Total Allowable Catches, TACs).The fishery is divided into four different components, with TACs and advice tailored to each one. These are:A-fleet: directed herring fisheries for human consumption, in the North Sea and eastern English Channel (ICES areas 4 and 7d), includes herring bycatches in the Norwegian industrial fishery.B-fleet: bycatch by industrial sprat, Norway pout and sandeel fisheries in the North SeaC-fleet: directed herring fisheries for human consumption, in the Skagerrak and Kattegat (ICES area 3a)D-fleet: bycatch by industrial sprat, Norway pout and sandeel fisheries in the Skagerrak and KattegatThere is separate management advice for A&B fleets and C&D fleets, therefore they are rated separately. This rating covers A&B fleets. The main management measures in this area are TACs for the A&B fleets in areas 4 and 7d. These TACs do not cover area 3a and therefore should be set below total recommended limits to allow for catches there. ICES estimates that in 2024, 500t of herring were caught in 3a. The A&B TACs have ranged from 80%-97% of scientifically recommended limits in the past 5 years, below the scientific advice. On average from 2021-2025, the TAC was 93% of the advice. Therefore, management is in line with scientific advice.However, total catches of NSAS herring have been too high. Catches have consistently exceeded TACs by 6% on average from 2020 – 2024. Catches have been below advice since 2020 averaging around 97% of advice, excluding 2023, when catches were slightly above advice. However, as the total catches include C&D fleet, it is not possible to compare them to the TACs.Other measures include:A Minimum Conservation Reference Size (MCRS) of 20cm for the A-fleet (3cm above the size of maturity). Catches below this size must be landed but can’t be sold for human consumption and so are less valuable.Closed areas to protect either spawning or juveniles. These are often small and are usually seasonal.A limit on herring bycatch. Up to 20% of the weight of sprat catches can be herring.High-grading is banned, which prevents discarding small or low-value fish to make space for larger and higher value individuals.In 2022, 24% of the North Sea catch in numbers was juveniles, increasing to 27% in 2023. Most young herring are caught by the B-fleet, equating to 81% of the total catch in numbers for area 4b in 2023. Juvenile catches are of concern, given the low recruitment to the stock since 2002, with a very low recruitment estimated for 2025 and the resulting downward stock trajectory. When the B-fleet TAC is reached, fisheries with bycatches of herring should be stopped. ICES estimates that B-fleet caught 4,958t of herring in 2024, while the TAC was set at 7,716t - so this does appear to be fully effective at present. Catches by the D-fleet also include juveniles because small-meshed nets are used, so total juvenile mortality could be higher than recommended.NSAS herring has several spawning components. This includes the Downs herring, which spawns in southern North Sea and English Channel (4c and 7d). To help protect this component, a limit of 11% of the total North Sea TAC can be taken from this area. ICES recommends that this be continued in order to give continued protection.There are a number of ways for herring quotas to be transferred between areas, fleets and even years. In 2025, ICES noted that it could not assess the effect of this.Another herring stock - Western Baltic Spring Spawning (WBSS) herring - is caught by the A and C Fleets. WBSS is highly depleted and has a zero-catch recommendation. It is mostly found in area 3a but also extends into the northern North Sea (4a) during its summer feeding migration.In previous years, it was assumed that C-fleet would catch most WBSS as it is targeting herring in 3a. Scientific advice indicated for both fleets in 3a (C and D) to have a zero TAC, to protect the WBSS stock. However, in 2024 the TAC was set at 22,793 though catches have been limited to 969 tonnes for the Union fleets and 200t for Norwegian Fleets. Additionally, 100% of the herring quota for area 3a could be transferred to the North Sea (A-fleet). In previous years this had been limited to 50%. This has changed fishing patterns and predictions.From 2022 to 2024, about 4,028 tons of WBSS herring were caught annually in the North Sea (A – fleet), with catches expected to remain much higher there than in other areas in 2025. Without stricter area and seasonal fishing limits in 2026, catching WBSS herring in the North Sea will likely continue and hinder the stock’s recovery.In 2023, A-fleet was assumed to catch most WBSS herring. It was predicted that around 80% of the total WBSS catches would be taken in 4a, although no figure was given for the actual catch. It was expected that 661t would be taken by C-fleet in 3a. D-fleet is assumed to catch 0t.Herring spawning grounds are generally near coasts and are vulnerable to human activities, especially from aggregate extraction and wind farms. It is important to protect spawning grounds and reduce these impacts. 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 impacts Targets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidence Timeframes for stock recovery Improved 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 bycatch Stakeholder engagement A North Sea Herring FMP has been proposed, coordinated by the Scottish Government 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].

Some North Sea herring is caught by purse seining. There is bycatch of the depleted Western Baltic herring, impacting recovery. Herring are important prey for many species, so removing them by fishing may have wider ecosystem impacts.North Sea Autumn Spawning (NSAS) herring are caught by a variety of fleets, ranging from small purse seiners to large freezer trawlers. This rating covers purse seine. The main potential impacts of this fishery are bycatch, and ecosystem impacts from removing an important prey species.As well as North Sea herring, another herring stock - Western Baltic Spring Spawning (WBSS) herring - is also caught by the A and C Fleets. WBSS is highly depleted and has a zero-catch recommendation. It is mostly found in area 3a, but also extends into the northern North Sea (4a) during its summer feeding migration.From 2022 to 2024, about 4,028 tons of WBSS herring were caught annually in the North Sea (A – fleet), with catches expected to remain much higher there than in other areas in 2025. In 2022, A-fleet was assumed to catch most WBSS herring. It was predicted that around 80% of the total WBSS catches would be taken in 4a, although no figure was given for the actual catch.ICES notes that without stricter area and seasonal fishing limits in 2026, catching WBSS herring in the North Sea will likely continue and hinder the stock’s recovery.Herring are an integral part of the North Sea ecosystem. As plankton feeders, they form an important part of the food chain up to the higher trophic levels. Both juveniles and adults are an important food source for demersal fish, birds and sea mammals. This includes the depleted North Sea cod population, which may not be able to recover at the current herring biomass. ICES states that it is highly likely that the North Sea requires a certain threshold of herring biomass to achieve Good Environmental Status (GES).If herring biomass is very low, other species, such as sandeel, may replace it. It has been suggested that the shift from herring to sandeel as prey for seals along the English coast in the 1970s resulted from the collapse of the herring stock.Marine mammals and other species can be drawn to purse seines as they often feed on the species being caught. However, reports indicate that bycatch is low. There have been some studies and deployments of observers, and none reported cetacean bycatch, although there was not full coverage of the fleet. There have been some instances of seal bycatch in pelagic trawls, but these have mostly been in north-western Scotland. There is no data available about purse seine bycatch. Seal populations in the UK are not threatened.Seabird bycatch is unknown, but gannets have been observed. Sampling is too low for accurate reporting, but ICES reports that seabird bycatch in the North Sea is 'comparatively rare'.It is possible for purse seines to make contact with the seabed, although this is not common as they are not targeting seabed species.