Crab, brown or edible
Capture method — Pot or creel
Capture area — North East Atlantic (FAO 27)
Stock area — Western Channel
Stock detail — VIIe
The status of the stock in the Western English Channel is good with spawning stocks around the level required to produce Maximum Sustainable Yield. Exploitation levels are moderate to low and around the levels required to produce Maximum Sustainable Yield. Avoid eating crabs below the minimum landing size (13-14cm in most areas of the UK) and crab claws, unless it is certain they have been removed from the crab body after landing. Egg-bearing or “berried” females should be avoided at all times to allow them to spawn.
The brown crab is commonly found in the North Atlantic Ocean, North Sea, less so in the Mediterranean. It is the heaviest British crab and easily identified by a characteristic pie-crust edge to the carapace or shell. They are found in waters down to 100 m. Brown crabs are highly fecund. Mating activity peaks in the summer when the female has moulted with spawning occurring in the late autumn or winter. Egg carrying females are largely inactive over the winter brooding period before the eggs hatch in the spring and summer. Between 250,00 to 3,000,000 eggs are held by the female for 8 months until they hatch into planktonic larvae. After around five weeks in the plankton, the crab larvae settle on the seabed. Juvenile crabs settle in the intertidal zone and remain in these habitats for 3 years, until they reach 6-7 cm carapace width, at which time they migrate to subtidal habitats. The crab is encased in a hard, rigid shell, which, like other crustaceans, has to be shed at intervals to permit growth. Moulting takes place at frequent intervals during the first years of a crab’s life, but only every two years after it is grown and this is mirrored by a slowing of growth rate. Growth is dependent on the frequency of moulting as well as the increase in size on each moulting occasion and it typically takes about four or five years for a juvenile crab to grow to commercial size. They can grow up to about 25 cm carapace width, with the larger specimens inhabiting deeper water. Growth rate varies between areas, and animals will typically reach a minimum landing size of 140mm carapace width at 4 to 6 years old. Environmental variables e.g. sea temperature related to geographical area and fishing pressure affect the size of maturity with animals in more northerly latitudes growing and maturing more slowly. Minimum landing sizes vary around the British coast from 150mm in the Western Channel to 115 mm in Norfolk for example. Edible crabs can live for up to 100 years but average age is around 25 to 30 years, and sexual maturity is reached after approximately 10 years, but can be as early as 3 to 4 years. Female brown crabs in Scottish waters typically mature between 130 and 150 mm CW. In Orkney research has shown that sexual maturity can be reached at 115 to 120 mm. The sex of a brown crab can be determined by the shape of the abdomen; the males being narrow and the females being broad and rounded for carrying eggs. Stock boundaries for edible crab remain poorly understood and both sexes move quite widely at times; females in particular have been shown to travel large distances in relation to spawning activity.
Criterion score: 0.25 info
The brown crab (Cancer pagurus) and the European lobster (Homarus gammarus) are both highly valuable shellfish species in the North eastern Atlantic. Both species are typically caught using baited traps.
Brown crab is widely distributed in coastal waters of the Mediterranean, Atlantic, English Channel and North Sea.
Availability of fishing activity data and the similarity of their respective biological attributes has led to fisheries scientists using the same or similar stock assessment methodologies for both species. Furthermore, the same fisheries scientists within each fisheries institute are often responsible for both crab and lobster stock status assessments.
The Centre for Environment Fisheries and Aquaculture Science (Cefas) provides management advice on the stocks of Cancer pagurus and Homarus gammarus in English and Welsh waters based upon the assessments performed every two years.
Cefas use three datasets to assess brown crab and lobster fisheries in England and Wales: landings, fishing effort and size distribution of landings. The landings and fishing effort data for over 10-meter vessels come from mandatory EU logbooks. For under 10-meter vessels the landings data are collected from first sales notes and the fishing effort from Monthly Shellfish activity returns (MSARs). Scientific officers visit ports frequently to collect size data. Additional size data have also been incorporated from local Inshore Fisheries and Conservation Authorities (IFCAs) since 2013.
The status of the stock of Edible Crab in the Western English Channel is good with spawning stocks around the level required to produce Maximum Sustainable Yield. The exploitation levels are close to the levels required to produce Maximum Sustainable Yield (males below, females above). The status of the stock has not changed since the last assessment in 2014 or since the assessment carried out in 2012.
Criterion score: 0.5 info
There are a range of measures available for the management of UK crab stocks. National legislation restricts the number of shellfish licences available (in England and Wales) and prohibits landing of berried and soft crabs. Increased monitoring of landings and effort was introduced in 2006 for boats under 10m in length in all areas of the UK.
EC legislation sets a minimum landing size of 130mm for crabs in the North Sea south of 56 degrees N. It also restricts the proportion of crab landings which comprise detached claws caught by pots or creels to less than 1% by weight of total catch. Other gear types are restricted to a crab claw by-catch limit of no more than 75kg per day.
In coastal waters out to 6 miles, potting is regulated by a number of Inshore Fishery Conservation Authority (IFCA) byelaws.
Within the Devon and Severn IFCA an Inshore Potting Agreement prohibits trawling in a designated static-gear area off Start Point. Implemented in 1978 to restrict the use of towed gears in inshore areas that had traditionally been used by static-gear (pot and net) fishers the IPA is a zoned fishery management system covering some 500 square kms. Since 2002 the previous voluntary agreement is now enforced by Government legislation. Although established to reduce conflict between mobile and static fishing gears the closure has created positive environmental benefits such as increased biodiversity and abundance of benthic (bottom dwelling) species. Benefits to other fisheries are also well documented. For example, increased fecundity of scallops in the no-trawl area provide more spill over spat to outside fished grounds. A minimum conservation reference or landing size of 160 mm is in force for male (cock) crabs and 150 mm for female (hen) crabs. There is also a prohibition on the landing of crab parts e.g. claws; and taking or selling egg bearing or soft shelled edible crabs.
Criterion score: 0 info
Pots are a highly selective method of fishing. Undersized animals including ‘soft’ or moulting crabs can be returned to the sea alive. However, many pots in use now, known as parlour pots, combined with mechanical hauling and increasing numbers of pots, have contributed to the potential unsustainability of the fishery in many areas.
Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.Abalone
Clam, Manila (Farmed)
Crab, brown or edible
Lobster, Norway, Langoustine, Dublin Bay prawn or scampi
Mussel, mussels (Farmed)
Oyster, Native, oysters (Caught at sea)
Oyster, Native, oysters (Farmed)
Oyster, Pacific, oysters (Caught at sea)
Oyster, Pacific, oysters (Farmed)
Prawn, King (whiteleg), prawns
Prawn, Northern prawns, Northern shrimp
Prawn, Tiger prawns (Farmed)
Scallop, King, scallops
Scallop, Queen, scallops
Squid, Japanese flying
ReferencesCefas. 2017. Edible crab (Cancer pagarus) Stock Status Report 2017.
Cefas. 2014. Edible crab (Cancer pagarus) Stock Status Report. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/462265/2014_Crab_assessments.pdf (Accessed 6 November 2017)