Brown crab

There is concern for both biomass and fishing pressure of brown crab in Northern Ireland.Route 2 (data limited) scoring has been applied to this rating owing to a lack of reference points for biomass and fishing pressure. Brown crab has a high resilience to fishing pressure.In 2023, 593.4 tonnes of brown crab were landed by NI registered vessels. This is an increase from recent years, with the lowest landings in 2020 at 509.3 tonnes. However, the 2023 landings are still below the peaks seen in 2011/2012 and 2017/2018 when landings exceeded 1000 tonnes. The total number of pots being used (effort) has also been increasing since 2020, when 17,802 pots were used compared to the 22,228 pots in 2023. Over the last 5 years, the average number of pots used was 21,142. This is slightly higher than the 18-year average of 21,049. Therefore, there is concern for fishing pressure.A length based model was used to examine the health of the brown crab stock. For the stock to be healthy, the mean length should be at the size at which growth is optimum (known as Lopt, this is 196.3mm carapace width for males, and 172.4mm for females). The output of the assessment indicates that males have been below Lopt since 2010, and females since 2016, indicating continued overexploitation of both sexes. Mean size of landed males in 2023 was 170.0mm, and for landed females it was 171.2mm. The data used in the assessments excludes lengths from crabs in Strangford Lough which are felt to have a different growth rate.A commercial landings per unit effort (LPUE) time series has also been used to indicate stock trends. The advice is based on the ratio of the mean of the last two index values (Index A) and the mean of the three preceding values (Index B), multiplied by the recent average catch (3 years). A precautionary reduction is applied as the indicator of size of crabs is below Lopt. The latest stock assessment shows that Index A is 1.45 kg/pot, and Index B is 1.70 kg/pot, a decrease of 0.25 kg/pot. The LPUE trend has decreased steadily since 2007. As less crabs are being caught per pot, there is concern for the biomass.Catch advice also states that catches should be reduced in line with the declining LPUE trends, and the size indicator of crab catches. This supports that landings in 2025 should be no more than 394 tonnes. This is 31.6% below the average landings from 2021 to 2023. The LPUE series is derived from reported landings data. This data is reliant on accurate self-reporting from commercial fishers. Methods for automated data collection would provide more detail on effort trends, including the duration over which pots are deployed.

Management of brown crab in Northern Ireland requires considerable improvement.The Northern Ireland (NI) brown crab fishery is managed by the Northern Ireland Department of Agriculture, Environment and Rural Affairs (DAERA). This is a data limited fishery but stock advice sheets that are produced annually by the Agri-Food and Biosciences Institute (AFBI) allow for a better understanding of the stock.In recent years, calls from the fishing industry for better regulation in NI have led the prohibition on the landings of berried crab, soft-shelled crab, and detached crab claws. There has also been an increase in the minimum landing size, which is now 150mm. However, this remains below the Lopt (mean length for a healthy stock) for both sexes, with both male and female brown crabs considered overexploited in Northern Ireland.In Strangford Lough, there are also restrictions on fishing in certain areas below 10 metres deep.All vessels registered in the UK must have a domestic fishing vessel license to fish within the UK EEZ for sea fish that will be sold. No new licenses are being issued. All commercial vessels under 10m, with a shellfish license, are required to complete Monthly Shellfish Activity Return (MSAR) forms for the Marine Management Organisation (MMO). These must include the catch and retained weight each day along with the date, name of the vessel, vessel registration number, gear type, area and port of landing. All vessels over 10m do not need to complete MSAR as they will be completing an EU logbook of catches. For all vessels, effort is reported as days fished, and not as pots fished. However, the restrictive shellfish license is not thought to restrict expansion of the NI fishing fleet as licenses with shellfish entitlements can be imported from anywhere in UK. In NI, you also do not need a permit to fish recreationally for crabs and lobsters, with a daily limit of five crabs and one lobster. This fishery is also covered by the Western Waters Regime, with vessels 15m and above restricted to 220 days at sea in ICES area 7 between 1 January and 31 December. Crab and lobster fisheries are not subject to Total Allowable Catch (TAC) regulations or national quotas, meaning there are no formal limits on the quantities that can be landed. Instead, AFBI provides annual scientific advice on sustainable catch levels. However, these advisory thresholds continue to be exceeded, with 2022 landings 46.7% above recommended levels and 2023 landings 55.7% above advice. DAERA have also not introduced a pot limit for crab and lobster fisheries.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 engagementA Northern Ireland non-quota shellfish FMP has been proposed, coordinated by DAERA, which 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/publications/joint-fisheries-statement-jfs/list-of-fisheries-management-plans

Crab pots have low seabed impacts when deployed and retrieved correctly. They are also selective towards larger individuals, and can mitigate bycatch through escape panels.In the UK, brown crab and European lobster are fished together in a mixed fishery with seasonal and regional variation of target species taking place. The key fishing season for brown crab in the UK takes place from May to December. Crabs are caught in pots, also known as creels, and can be fished individually or as part of a fleet of up to 100 pots, depending on the size of the boat and crew. Pots are portable traps made of wood or steel wire and plastic. The crab is baited into the initial part (the chamber) and moves into the secondary part (the parlour) where it becomes trapped.In brown crab fisheries, there is no legislation or regulation to standardise the type of pot used. They tend to be highly selective as undersized animals can be returned to the sea alive and survival rates for non-target organisms are thought to be high. More than half of the bycatch caught are predicted to survive, although there is little available research to prove this. Measures to further reduce bycatch include the use of escape panels to allow undersize animals and bycatch to escape pots.Habitat impacts from potting are low but can occur during deployment, soak time or hauling of the pot, impacting the benthic habitat and associated species through contact with the pot or end weight, or by scouring from ropes. Research that has taken place suggests that while some damage does occur, it is unlikely to be significant unless potting intensity is high (defined as approximately 30 pots per 500 square metres). The most damage occurs when traps are set in sensitive habitats such as rocky reefs, seagrass beds, and maerl beds. These ecosystems play a crucial role in supporting marine biodiversity by providing nursery grounds, shelter from predators, and settlement areas for invertebrate spat.To safeguard these vulnerable habitats, potting is prohibited in several designated conservation areas within Northern Irish waters. These include the Red Bay Special Area of Conservation (SAC), Rathlin Island Special Protection Area (SPA), Skerries and Causeway SAC, and the Waterfoot Marine Conservation Zone (MCZ), where the use of static fishing gear is restricted.Lost pots can pose an additional risk to marine life through ‘ghost fishing’, where abandoned gear continues to trap and entangle species. As fishing gear is a financial investment, there is incentive to maintain and recover lost pots. The occurrence of ghost fishing can also be reduced by the use of appropriate gear designs and release devices.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.