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Scallop, King, scallops

Pecten maximus

Method of production - Caught at sea
Capture method - Dredge
Capture area - North East Atlantic (FAO 27)
Stock area - Wales
Stock detail - Cardigan Bay
Certification -
Fish type - Shellfish

Sustainability rating Click for explaination of rating

This fish, caught by the methods and in the area listed above, is not the most sustainable choice of fish to eat. Click on the rating icon above to read more and on the alternatives tab below to find more sustainable fish to eat.

Sustainability overview

The scallop stock in Cardigan Bay appears to be healthy with regular recruitment. There are restrictions on scallop dredging and the use of VMS is compulsory. Fishing effort has to be spatially and temporally controlled to maintain a healthy stock level and limit ecosystem impacts of the fishery. Avoid eating scallops below their legal minimum landing size and during their breeding season (April to September).


King scallops are bivalve molluscs found in a range of depths from shallow waters in sea lochs to over 100m. They inhabit sandy-gravel and gravel seabeds. They have 2 shells or valves, the upper being flat, and the under or right valve, cup shaped. They are hermaphrodites (i.e. both male and female) and become fully mature at about 3 years old (80 to 90mm in length). Spawning occurs in the warmer months, from April to September. The species can grow to more than 20cm in length and live for more than 20 years, although average sizes are in the range of 10-16cm.

Stock information

Stock area

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Stock information
The scallop, both King and Queen scallops, fishing industry employs 75 fishers in Wales and scallops are the second most valuable species landed in Wales. However there is relatively little currently known about the state of scallop stocks as no formal stock assessment is carried out in England and Wales. Bangor University has started to collect stock information and research being carried out by the University at the moment will better inform stock assessment through increased understanding of sub-stocks. The stock in Cardigan Bay appears to be healthy and has a high abundance of young scallops indicative of healthy recruitment of scallops to the fishery.


A stakeholder-based National Scallop Group, coordinated by Seafish, was established in 2008 to address industry issues, including environmental impacts. There are no quotas set for this species. Fleet capacity is controlled by Welsh Assembly Government (WAG) permit. All vessels in the fishery are required to carry Vessel Monitoring Systems (VMS). VMS provides a fisheries managment agency with accurate information about the location and activity of regulated fishing vessels and is a cost effective tool for the successful monitoring, control and surveillance (MCS) of fisheries activities. There is an annual seasonal closure when scalloping is prohibited in Welsh waters from 1st May to 31st October. Scalloping is prevented in all but one area of Cardigan Bay Special Area of Conservation (SAC) and in coastal waters outside and within other parts of SACs. There is also a total ban on fishing with dredges between the shore and 1 nm. The maximum permissable engine power for scallopers in Welsh waters is 221 kw. WAG are considering further permit conditions.

Capture information

Welsh scallop fishermen are working closely with scientists and fishing gear technicians from Seafish to develop low impact and efficient scallop gears that will reduce seabed disturbance. In Cardigan Bay no dredging is permitted between 0 and 1 nautical mile (nm). Between 1 and 3 nm the number of dredges is restricted to 3 per side, provided the vessel is less than 10 metres.; 4 a side between 3 and 6 nm; and outside 6 nm a maxiumum of 7 dredges per side. The minimum landing size for scallop in EU waters is 100mm, except in the northern Irish Sea (Isle of Man), Eastern English Channel and Welsh waters where it is 110 mm. Recent survey results indicate that the catch in the Bay were mostly "clean", i.e. little or no bycatch and consisting mainly of the target species.

Read more about capture methods

Lambert, GI, Hold N, Hinz H, Kaiser MJ (2012) Welsh waters scallop survey-Cardigan Bay to Liverpool Bay June 2012. Bangor University, Fisheries and Conservation Report No. 18.

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