King scallop

The king scallop population in Northern Ireland is relatively stable, but landings have been above scientific recommendations. Therefore, there is concern for fishing pressure but not biomass.King scallop fishing in Northern Ireland developed in the 1930s. Landings were relatively constant at around 350 tonnes throughout the 2000s, then rapidly increased to 1,600 t in 2014 following a boom in the stock. They have since declined and in 2022 were around 400t.An annual survey has been carried out since 1992 to monitor the scallop stock in Northern Ireland. Since 2021, the Agri-Food and Biosciences Institute (AFBI) has provided stock assessments. The most recent assessment was released in 2023 using data up to 2022. There are no reference points to indicate what a healthy stock size or fishing pressure should look like.Route 2 (data limited) scoring has been applied to this rating owing to the lack of reference points. King scallops are considered to have high resilience to fishing pressure.Biomass gradually increased between 1992 and 2010, more than doubled by 2014, and then halved by 2016. A biomass index is used to monitor biomass changes and account for annual fluctuations, based on the annual scallop survey. The average of the most recent 2 years (Index A) is divided by the average from the preceding 3 years (Index B). In 2023, the ratio of A:B was 1, indicating a stable biomass. Biomass in 2021 and 2022 was above the level prior to the 2014 peak, suggesting a general increasing trend over time. While there is no reference point to indicate a healthy level for the biomass, we conclude that there is no concern because of the overall increase and recent stability.There is no clear measure of fishing pressure. Landings have followed a similar pattern to the biomass, peaking in 2014 and then declining. The stock assessment notes that landings data are self reported by fishers and do not include any landings by Irish vessels fishing from this stock.Landings in 2022 (393t) were above the 2000-2010 average (350t) prior to the peak, but below the long term (2000-2021) average of 612t. Recommended catch for 2021 and 2022 was 351t. Landings for 2021 and 2022 were 466t and 393t respectively, exceeding the advice for those years. There are no catch limits in place to ensure that scientific advice is followed. Therefore, we conclude that there remains concern for the fishing pressure.Catch advice increased to 507t in 2023 and decreased to 379t in 2024. Data has not yet been published to indicate whether this advice was followed. Work is underway by AFBI to improve the understanding of scallop stock structure, which could significantly improve management of the fisheries in Northern Ireland and the Irish Sea in future.

Some management measures are in place to control the king scallop fishery within Northern Irish waters, including seasonal and night time closures. However, there are no measures that respond to stock status to ensure that scallop populations stay at healthy levels.Most (around 65%) of the scallop catch from Northern Irish waters is by Northern Irish vessels, and most of the rest is from Scotland and the Isle of Man. The Department for Agriculture, Environment and Rural Affairs (DAERA) manages fisheries in inshore Northern Ireland. There is currently no Fishery Management Plan, harvest strategy, or quota for scallops in Northern Ireland. There is a stock assessment to provide catch advice, but this is not currently used to set management measures.During 2023 and 2024, DAERA is developing proposals for a Northern Ireland Inshore FMP, which will cover brown crab, velvet crab, lobster, king scallop and queen scallop. Details of the FMP are not yet known. Until it is in force, it will not affect the rating for this fishery.Scallop fishing in Northern Ireland is primarily managed through the Conservation of Scallops Regulations (Northern Ireland) 2008 and The Scallop Enhancement Sites (Prohibited Methods of Fishing) Regulations (Northern Ireland) 2022. Measures include:A minimum landing size (MLS) of 110mm to protect the breeding stock. Cefas indicates that scallops are mature at around 80mm, although growth rates vary. Therefore, juveniles are protected. However, it may not fully protect the breeding stock because scallop reproductivity increases with size. Discards of below minimum size scallops take place, but a high survival rate is assumed and therefore this is not considered to have an impact on the stock.A ban on fishing at night (8pm-6am) and during the weekend.A limit of 12 dredges per boat.A ban on diving for scallops between June and OctoberSince 1986, the British waters of the Irish Sea between 55 and 51'30 degrees north have been closed to scallop fishing from June to October each year.  However, it is not clear if there is displacement of fishing activity to waters outside this area, including the north coast of Northern Ireland, which may increase pressure on the scallop stock here.A number of these measures limit effort in the fishery to an extent, especially the curfews and seasonal closure that limit activity to certain times of the year. However, there are no measures, particularly effort controls or catch limits, that can respond to stock status. Therefore, management cannot adequately protect the stock from overexploitation.Since 2022, scallop dredging and diving (except for scientific purposes) has been banned from 4 reseeding sites for king scallop stock enhancement. This could support recovery of scallop stocks. In addition, closed areas are important for controlling the impacts of scallop dredging on seabed habitats. However, reseeding and enhancement are not always successful and may take years to have an effect, so it is too early to understand the impact of these measures.The Western Waters Effort Regime limits how many days large boats (over 15m) can spend dredging for scallops in ICES area 7 (English Channel, south-west England, and Irish Sea). Cefas reports that in recent years, this has limited fishing effort by UK boats, but not French boats.Project UK is implementing Fishery Improvement Projects (FIPs) on twelve UK fisheries that are important to the UK market. This includes dredged scallops around the UK. The FIP began in 2019 and has an end date of April 2024, at which point it should be ready to undergo MSC certification.The FIP has been successful in tackling some issues, including improving understanding of stock boundaries, bycatch and habitat impacts. These outcomes are not inconsiderable. However, there has been very little change to how scallop fishing is carried out, and there is not enough in place to protect scallops from being overfished. For example, there is no harvest strategy that can respond to stock status by reducing fishing pressure when stocks decline. There also appears to have been no change in fishing practices to reduce bycatch or habitat impacts. Therefore, we do not consider the FIP to have addressed all key environmental issues in this fishery, and it does not meet GFG guidelines for application of a FIP Improver score.The annual FIP report from 2024 indicates that it currently is failing on harvest strategy and harvest control rules, which will prevent it from achieving certification. The FIP lists Fishery Management Plans (FMPs) as a delivery mechanism for improvements. The proposed FMP for king scallops in England and Wales does not include a harvest strategy, although it does include a proposal to develop one. An FMP in Northern Ireland is expected to be consulted on in 2024. There are no plans to develop a scallop FMP in Scotland. Given that the FIP will end in April 2024, and no FMPs will be delivering harvest strategies or control rules by that point, we do not consider it possible for this key issue to be addressed within the FIP timescale.More information is here and here.

Scallop dredging can be very damaging to seabed habitats and species. There are some vulnerable species and habitats here, but dredging is now banned from some protected areas. There are quite high levels of bycatch, which may have impacts on other species.Most Northern Ireland scallop catches (around 95%, according to MMO data) are by dredging, with much of the rest from otter trawling. The main environmental impact from dredging is its effect on the seabed. This impact varies depending on which habitats the dredging happens on (see below for more details).Some marine habitat mapping has taken place in Northern Ireland, but more is needed to ensure all vulnerable areas are recorded. In addition, the dredge footprint by vessels over 12m is recorded, but there is no data on the location of dredging by vessels below 12m. Therefore, better data is needed to fully understand the impact of this fishery.A State of the Seas report from 2011 indicates that the most common habitats in Northern Irish seas are mixed coarse sediment, sand and mud. Seabed data from EMODnet indicates that there may be overlap between dredging (over 12m) and sand, coarse sediment, and rock.Sand and mud are typically less vulnerable to the impacts of dredging, but rocky habitats are more sensitive. An analysis of fishing effort by the over 12m fleet between 2012 and 2016 indicated that a small proportion of the total dredging effort (less than 1%) was taking place within Marine Protected Areas (MPAs), mainly on highly vulnerable rocky reefs. Dredging was also happening on or near seagrass beds, which could be affected by sedimentation as a result. An assessment of the habitat impacts of dredging in Northern Ireland in 2020 indicated that impacts were "significant" for sandbanks (including seagrass), maerl, and reefs (Sabellaria and hard bedrock). The Outer Belfast Lough Marine Conservation Zone was designated to protect the ocean quahog. Evidence from sonar scans shows that dredging has occurred at high intensity within the MCZ and was likely to remove a large proportion of the population and/or cause damage to the shells and body.In January 2023, mobile gear was banned from 9 MPAs, covering around 340km2, and 4 scallop enhancement sites. This equates to around 0.05% of Northern Ireland’s marine area, which is around 6,800km2. The protected areas include locations where dredging overlapped with rocky habitats and the ocean quahog. There are also limits on the number of dredges per boat and a curfew to protect nocturnal species. Effort is also limited by a seasonal closure to protect scallop stocks, which runs from July-October in the Irish Sea.Therefore, impacts from dredging are mitigated to some extent, but more data is needed on dredging locations and affected habitats. Sub-surface disturbance in parts of Northern Ireland’s marine area is high. An analysis of the impacts of UK scallop dredging in 2021 concluded that fishery interactions were likely to cause up to a 10% change in the ecosystem, with the impact likely to take up to 20 years to recover.Bycatch by dredges may also be of concern. Non-quota species are allowed to be caught as bycatch in scallop fisheries, if they comprise less than 5% of the total catch. Bycatch reporting in UK fisheries in general is poor. However, data is recorded during the annual scallop survey by AFBI. In 2022, the main bycatch species were common starfish, edible urchin and queen scallops. Bycatch was between 19% and 77% of the total catch, which suggests quite high rates. However, most (around 75%) of the animals that scallop dredges interact with remain on the seafloor. They are often damaged, and so there may be impacts on populations in the affected areas. Therefore, bycatch surveys may not capture all impacts of dredging on other species.About scallop dredging:A typical king scallop dredge, known as a Newhaven dredge, is a heavy steel frame with a chainmail net. There is a toothed bar at the front that penetrates the seabed, flipping the scallop into the net. Dredges are connected to a tow bar that travels over the seabed, and there can be up to 20 dredges per bar. The number of dredges and tow bars are limited by the engine power of the vessel, and by various legislation around the UK.On average, global studies estimate that scallop dredging penetrates seabeds by around 6cm, and can reduce community abundance and species richness by 8-12% per dredge pass. Recovery can take months or years, depending on the species affected. The impacts vary, depending on the type of seabed, the species that live there, and the level of natural disturbance from waves and storms. In more disturbed areas, the habitats and species may be faster growing and more easily able to recover. Sheltered and inshore areas are more likely to have slow-growing, delicate species, like maerl, seagrass, horse mussels and seafans. Sandy areas are generally less sensitive and more easily able to recover. Gravelly seabed communities are more susceptible because they are quite stable and therefore more likely to have larger, longer-lived species.Impacts can include:Removal of species from the seabed and reduction of biodiversity. In particular, it can change the composition of the ecosystem towards shorter lived and faster growing species that can more easily recover from dredging.Reduction in the complexity of the seabed, which can reduce the number of suitable habitats on which species can settle.Resuspension of sediments, which can smother species and prevent photosynthesis or filter feeding.