Black-bellied monkfish

Stock Status Score: 0

Black-bellied anglerfish in the Celtic Seas and Bay of Biscay is not overfished and not 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 2026 using data up to 2026. The next assessment is expected in 2027.

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 spawning stock biomass (SSB) in this area has increased overall from a low of around 10,997 tonnes in 2003 to 53,501 t in 2026. This is well above MSY Btrigger (16,776t) and the GFG proxy for BMSY (23,486 t). Therefore, the stock is not in an overfished state.

Fishing mortality (F) has been generally declining since 2013 from 0.21 to 0.103 in 2025. This is below levels associated with Maximum Sustainable Yield (FMSY: 0.163). The stock is therefore not currently subject to overfishing.

ICES advises that when the MSY approach is applied, catches in 2027 should be no more than 19,130 tonnes. This is a 14.6% reduction from the previous year’s advice due to the downward revision of the stock size.

Management of the Target Stock Score: 0.25

Alignment with Scientific Advice Score: 0.5

Monitoring, Control and Surveillance Score: 0.25

There is no management plan for black-bellied monkfish in the Celtic Seas (South) and Bay of Biscay, but some measures are in place, which are partly effective in managing the stock.

The EU multiannual plan (MAP) for stocks in in the Western Waters and adjacent waters applies to this stock. There is no agreed shared management plan with the UK for this stock. ICES precautionary approach is applied to catch advice. In 2022 reference points for black-bellied anglerfish were established for this Celtic Seas and Bay of Biscay stock using a category 1 assessment, providing more robust estimates of stock status and fishing pressure.

Management of the stock under a combined TAC (catches of two anglerfish species) prevents effective control of single-species exploitation rates and could lead to overexploitation of either species. Both species of monkfish, otherwise known as anglerfish: white anglerfish (Lophius piscatorius) and black-bellied anglerfish (Lophius budegassa), are taken in a mixed fishery, mainly with hake, megrim and Nephrops. The two anglerfish species are not totally separated in the landings, and landings are generally reported for the two species combined (L. piscatorius and L. budegassa). The combined landings are then split into species at a national level, based on the species composition in the sampling data. A single total allowable catch (TAC) covers both anglerfish species, and species-specific landings are estimated by ICES, whereby black-bellied anglerfish account for 41% of landings between 2021-2025, and white anglerfish make up the rest. ICES considers that management of catches of the two anglerfish species, under a combined species TAC prevents effective control of the single-species exploitation rates and could lead to the overexploitation of either species. However, currently the stock size of both species is increasing and neither species appears to be at risk of over-exploitation. Since 2019, the combined TAC has been set in line with advice. Compliance to the TAC is high, and according to ICES estimations, landings of both species together averaged consistently below the TAC and advice.

There is evidence of considerable potential for long-distance migration, and it is not clear whether this stock definition (Subarea 7, Divisions 8a-b, 8d) is appropriate. Because there is currently insufficient information to change the stock boundaries, the current stock definition remains unchanged. This presents a number of issues for management.

There is no minimum landing size for monkfish (anglerfish). Black-bellied anglerfish reaches maturity at around 65 cm, which corresponds to around 4-5 years. Consequently, these fish are being caught before they have had chance to reproduce. EU Council Regulation (No. 2406/96) laying down common marketing standards for certain fishery products fixes a minimum weight of 500 g for anglerfish.

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 

Capture Method Score: 0.5

Habitat Impacts: 0.5

Bycatch Impacts: 0.25

Vulnerable and ETP Species: 0.5

Ecosystems and Trophic Webs: 0.25

Otter trawlers interact with the seabed and can modify bottom topography and cause damage and removal of some biogenic features including vulnerable marine habitats and benthic communities. They can also bycatch vulnerable species.

Monkfish or black-bellied anglerfish is predominantly caught by beam trawling in the Celtic Seas and Bay of Biscay. Anglerfish are an important component of mixed fisheries, mainly caught with hake, megrim and Nephrops, but also sole, cod, and plaice. The fishery for anglerfish developed in the late 1960s. In recent years, France has taken the vast majority of black-bellied anglerfish (L. budegassa) landings; followed by Spain, Ireland and the UK. The majority of black-bellied anglerfish is consistently taken by demersal otter trawling, targeting demersal fish; accounting for 71% of catch. Gillnets (8%), beam trawls (11%) targeting demersal fish, and otter trawls targeting Nephrops (which tend to be further inshore and shallower) (7%), also contributed to catch. Black-bellied anglerfish are most abundant at depths of 200 - 500 m, and are taken both offshore and inshore. Juveniles are mainly found offshore in the western Celtic Sea and sometimes in the Bay of Biscay.

Demersal otter trawls have the potential to take relatively high quantities of bycatch. In the Northeast Atlantic there are reported catches of demersal elasmobranchs and endangered, protected and threatened (ETP) species (e.g. sharks, rays and marine mammals). Bycatch data is limited in many UK and EU fisheries as they are generally not well monitored. The common skate and spurdogs, are caught as bycatch in demersal trawl fisheries within the Celtic Seas and Bay of Biscay ecoregions, and deep-water sharks are reported to being caught in the mixed deep-water trawl fishery in the Celtic Seas. Therefore, interactions with Endangered, Threatened or Protected (ETP) species are considered to be possible. There have been no reports of bycatch of other non-target species in this fishery, although, incidental bycatch may occur as by nature species close to the sea floor (fish and invertebrate species) share the same habitat as monkfish. Bycatches of non-target species can make up a high proportion of catch weight in demersal otter trawls. A number of areas are closed to fishing at certain times of the year, e.g. the Trevose box, an areas of sea around 11,400 square miles extending from Trevose head in Cornwall to the Gower peninsular in South Wales from January to March. This is the spawning period for a number of demersal stocks, while it is primarily intended to reduce catches of spawning cod, other stocks are likely to benefit.

Anglerfish are ambush predators and feed opportunistically on passing prey, which is attracted using a fleshy lure on the illicium. The diet is dominated by fish and, to a lesser extent, cephalopods. Small gadoids have a relatively high importance in their diet. There are no reports of predators that specifically target anglerfish in European waters. Indirect predation by seals of netted fish is common though and seals may prey directly on anglerfish as well. There have been reports of anglerfish being predated upon by sperm whales, and juvenile fish by large cod.

Demersal trawls have contact with the seabed resulting in penetration and abrasion of habitat features. The impact of trawling on the seabed depends on the location and scale in which trawling occurs. For example, areas that are used to natural disturbance through tides and waves, are less sensitive to habitat impacts. Whereas areas not used to mobile towed gears are typically more sensitive to trawling. Trawl gears are known to have some of the greatest impacts on Vulnerable Marine Ecosystems (VME). Demersal otter trawls are likely to be operating on more sensitive, deeper, muddy ground, whereas the Nephrops trawlers operate on the shelf, where the seafloor communities are better adapted to disturbance. EU vessels are required to report significant catches of corals and sponges to assist mapping these communities and must move fishing operations at least 2-miles when they are encountered.

UK regulations to reduce the impacts of fishing on marine habitats and wider species are under development, in the meantime most EU regulations have been adopted. Under EU legislation, bycatch species should be managed within scientifically defined or, where data isn’t available, suitably precautionary sustainable exploitation limits. If stocks fall below trigger levels, measures can be brought in such as limits on characteristics or use of gear (e.g. mesh size, depth); time/area closures; and minimum conservation reference sizes.

Habitat protection measures across European waters include Marine Protected Areas. If those MPAs were found to be subjected to bottom trawling, the Marine Conservation Society would assign a default red rating unless there is evidence (e.g. environmental impact assessment) indicating the activity does not damage the integrity of the site. EU regulations prohibit bottom trawling below 800m and restrict activities between 400-800m. Spatial management is continually being developed, which will restrict the footprint of this gear on the seabed. However, there remains some uncertainty about the location of some sensitive seabed habitats so these remain at risk.

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.