King scallop

Information about Scottish West Coast king scallops is limited. There is not enough information to determine whether the population is at a healthy size, although it appears to be growing. Fishing effort has been decreasing, so there is not currently concern for fishing pressure. King scallop fishing in the west coast of Scotland developed in the 1970s. Landings peaked at around 6,500 tonnes in 2002 but have since declined to around 2,350t.Route 2 (data limited) scoring has been applied to this rating owing to the lack of a recent stock assessment. King scallops are considered to have high resilience to fishing pressure.The most recent stock assessments for scallops in Scottish waters were carried out in 2016. Annual scallop surveys have been carried out since then, but no stock assessments have been made available. The four survey areas are: Shetland, West Coast, North East Coast and East Coast. A fifth assessment area is in Orkney, where the first survey was carried out in 2019. Covid disruption has prevented additional surveys since then and there is no stock assessment for Orkney. This rating covers the West Coast (incorporating North West, Clyde and West of Kintyre).The 2016 stock assessment did not provide reference points for biomass for West Coast scallops, and could not provide any stock assessment for the Clyde area. However, it did show that the spawning stock biomass (SSB) was the highest on record in the North West zone and stable at high levels in the West of Kintyre. Fishing pressure was estimated to be at the long-term average in the North West, and low in the West of Kintyre.From 2017-2021, fishing effort for scallops in Scotland in general declined, and scallop landings per unit of effort (kW Days) increased. This suggests a potential increase in stock sizes. Scallop landings from the West Coast averaged 2,351 tonnes between 2018 and 2022. Landings have steadily declined since 2014, reaching 2,036t in 2022 - the lowest since records began in 1982.The changes in effort and the increase in LPUE suggest that scallop stocks have been able to grow under current levels of fishing pressure. Therefore, we consider there to be no concern for fishing pressure. However, there is no stock-specific data to indicate how effort or LPUE has changed for the West Coast stocks, and no benchmark to indicate what a healthy stock size would be. As a result of these data limitations, we remain concerned for the biomass until stock assessments can be provided.

Some appropriate management measures are in place to control the scallop dive fishery in the west coast of Scotland. Improvements are needed to better understand the stock and the fishery.Most of the scallop catch from the Scottish West Coast is by Scottish vessels (around 90%), and the remainder is from England, the Isle of Man, and Northern Ireland. Around 11% of the catches from this area are by diving. This rating covers the dive fishery in the west coast.There is currently no Fishery Management Plan, harvest strategy, or quota for scallops in Scotland. There are also no recent stock assessments to inform management. Management cannot therefore be responsive to changes in stock, and does not adequately ensure that fishing is controlled to protect the species. However, diving accounts for a relatively small proportion of total catches within the stock, and has little impact on habitats and other species. While improvements are needed, it does not require the same level of management as the dredge fishery.In the available catch data from the MMO, diving is not specified. ‘Passive gears’ is interpreted to mean ‘dive-caught’ in the case of scallops. The average catch by passive gears in the west coast from 2018-2022 was 264 tonnes. Landings have declined during that time, from 378t in 2018 to 212t in 2022. In the whole of Scotland, 539t of scallops were caught by diving in 2022.Scallop fisheries in Scotland are managed through the Regulation of Scallop Fishing (Scotland) Order 2017. Most measures relate to controlling the dredge fishery. The main measure that is relevant to the dive fishery is a minimum landing size (MLS) of 105mm to protect the breeding stock. Scallops are thought to mature at age 3 or around 80mm, although growth rates vary. Therefore, juveniles are protected. However, it is smaller than the MLS elsewhere in the UK, which is 110mm, and may not adequately protect the breeding stock because scallop reproductivity increases with size.There are no controls on catches or effort, although a license is required for commercial fishing. There are currently no requirements for vessels under 12m, which is the majority of dive vessels, to carry tracking devices. The fishery is therefore not well understood or monitored. However, a consultation was held in 2023 on rolling out tracking systems for under 12m vessels.In the 0-6nm zone, there are also non-statutory Regional Inshore Fisheries Groups (RIFGs). They do not have powers to set byelaws or implement management measures. The west coast, from the English border up to Cape Wrath, was covered by one RIFG (West Coast) until January 2023, when it was split into the North West and South West RIFGs. The Outer Hebrides also have an Inshore Fisheries Group (OHIFG). WC and OH RIFGs published Fisheries Management Plans in 2021 that are based on Scottish Government's Scottish Inshore Fisheries Strategy. WCRIFG's Fisheries Management Plan includes investigating management measures to conserve scallop stocks and reduce gear conflict, including increased MLS for scallops from MPAs, effort control, closed areas and seasons, and a stock assessment for the Clyde. In the Outer Hebrides, there are seasonal scallop dredging prohibitions in certain areas. There is also a Scallop Dredge Code to manage conflict with static gear such as brown crab creels. OHIFG's Fisheries Management Plan includes research into dredges with lower impact ('eco-dredge'), increasing MLS to 110mm, mapping scallop grounds and improving logbooks for better data collection.

Hand-diving for scallops is a very low impact fishing method, with no unwanted bycatch of other animals and very little impact on habitats.The average scallop catch from diving in West Scotland from 2018-2022 was 264 tonnes. This is around 11% of the catch from this area.Diving for scallops usually uses boats and scuba equipment. It involves gathering scallops from the seabed by hand, one at a time. Divers can ensure that they only remove scallops, and don’t affect any other species. The only potential damage would be from irresponsible practices, for example, making contact with seabed features such as biogenic reefs.It is important to note that shellfish can contain toxins, and therefore hand-dived scallops should be bought from processors that routinely undertake sampling of scallops for toxins. It can be dangerous to eat shellfish from areas where there is a high toxin, bacterial, or chemical contamination.