Crab, brown or edible
Cancer pagurus
Method of production — Caught at sea
Capture method — Pot or creel
Capture area — North East Atlantic (FAO 27)
Stock area — Cornwall
Stock detail — 7f, 7g
Sustainability rating
info
Biology
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.
Stock information
Criterion score: 0.75
info
Management
Criterion score: 0.5
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Capture Information
Criterion score: 0
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Alternatives
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
Limpet, Slipper
Lobster, European
Lobster, Norway, Langoustine, Dublin Bay prawn or scampi
Mussel, Chilean (Farmed)
Mussel, mussels (Farmed)
Oyster, Native, oysters
Oyster, Pacific, oysters
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
This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish. For
full details, please see the full wild-capture methodology available here.
Stock or species status
Score |
Descriptor |
0 |
Stock under fished and harvested within sustainable limits |
0.25 |
Stock fully fished and harvested within sustainable limits |
0.5 |
Stock level below sustainable level (BMSY) but harvested within sustainable limits |
0.75 |
Stock and fishing level or stock at increased risk |
1 |
Stock outside biological and/or safe fishing limits |
Management
Score |
Descriptor |
0 |
Well-managed |
0.25 |
Management requires some improvement |
0.5 |
Partly effective management |
0.75 |
Poorly managed and requires considerable improvement |
1 |
No relevant or effective management measures in place |
Capture method and ecological effects
Score |
Impact |
0 |
Very low impact |
0.25 |
Low impact |
0.5 |
Some or moderate impact |
0.75 |
High impact |
1 |
Very high impact or illegal |
Where environmental concerns from any one criteria are so great, a ‘critical fail’ may be triggered and the fishery awarded a default red
rating. For full details, please see the full wild-capture methodology available here.
The sustainability of fish can vary significantly depending on how and where it has been caught or farmed. Many single species are caught or farmed in a variety of ways and this range shows that, within a species, some sources may be more sustainable than others.
To find out specific ratings, click on the 'Show options for this fish' button under the image of the fish.
'Best choices' are rated 1 and 2 (green), 'Fish to Avoid' are rated 5 (red). Ratings 3 and 4 mean 'Think' (yellow and amber), as there are better rated alternatives.
Fish that are under review are shown with a question mark icon and no rating.
This system has been developed by the Marine Conservation Society to help consumers and businesses choose the most environmentally sustainable fish.
Seafood sources indicated as, 'To be assessed', are those that have not yet been assessed and assigned a rating or are undergoing a period
of review. These include sources previously rated by MCS for which the rating has lapsed, due to changes in the market or MCS priorities and
resources. Given that these sources are not fully assessed, the profile should not be used to infer the current sustainability of the
fishery or farmed species.
If you are interested in the sustainability of this seafood source, please let us know by emailing
ratings@mcsuk.org
Rating 1 (light green) is associated with the most
sustainably produced seafood.
Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5.
Ratings 3 and 4 mean don’t eat too often.
This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.
Rating 2 (pale green) is still a good choice, although some
aspects of its production or management could be improved
Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5.
Ratings 3 and 4 mean don’t eat too often.
This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.
Rating 3 (yellow) based on available information; these
species should probably not be considered sustainable at
this time. Areas requiring improvement in the current
production may be significant. Eat only occasionally and
check www.goodfishguide.org for specific details.
Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5.
Ratings 3 and 4 mean don’t eat too often.
This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.
Rating 4 (orange) should not be considered sustainable, and
the fish is likely to have significant environmental issues
associated with its production. While it may be from a
deteriorating fishery, it may be one which has improved from
a 5 rating, and positive steps are being taken. However, MCS
would not usually recommend choosing this fish.
Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5.
Ratings 3 and 4 mean don’t eat too often.
This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.
'Red improver' ratings are assigned to seafood sources which have been assessed and rated 5 (red) due to significant environmental concerns
with one or more aspects of their management, capture or production, yet credible efforts to improve these issues have been agreed through a
Fisheries or Aquaculture Improvement Project – a FIP or an AIP - and work is underway. Such projects are normally publicly listed at
www.fisheryprogress.org. MCS wants to encourage environmental improvements in fisheries and fish farms, and so does not recommend avoiding
these sources, as we normally do for seafood rated 5 (red rated).
'Best choice' fish are rated 1 and 2, Fish to Avoid are rated 5.
This system has been developed by the Marine Conservation Society to help businesses and consumers choose the most environmentally
sustainable fish.
Rating 5 (red) is associated with fish to be avoided on the
basis that all or most of the criteria for sustainablilty
have not been met.
Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5.
Ratings 3 and 4 mean don’t eat too often.
This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.