Mussel, mussels (Caught at sea)
Mytilus edulis
Method of production — Caught at sea
Capture method — Hand-gathering
Capture area — North East Atlantic (FAO 27)
Stock area — UK
Stock detail — All Areas
Sustainability rating
info
Sustainability overview
Mussels are widely cultivated and stocks generally considered to be under-exploited. The main methods of harvesting for wild and farmed mussels are dredging and hand-gathering. Hand-gathering is a more selective and sustainable method of harvesting mussels in the wild, and causes less disturbance than mechanical methods. The hydraulic elevator mussel fishery in the Exe estuary was certified as an environmentally fishery in July 2012.
Biology
Common mussels are bivalve molluscs found on shores throughout the north Atlantic, Mediterranean, North and Baltic Seas. They normally live in large aggregations, attaching themselves to rocks and each other with sticky threads known as byssus. They can be found from the high intertidal zone to the shallow subtidal zone. Found on the rocky shores of open coasts attached to the rock surface and in crevices, and on rocks and piers in sheltered harbours and estuaries, often occurring as dense masses. The shell is inequilateral and roughly triangular in outline. Size and shape vary considerably with environmental conditions, the colour usually purple or blue but sometimes brown. Shell smooth with a sculpturing of concentric lines but no radiating ribs. The ligament is inconspicuous. Length varies, specimens usually ranging from 5 -10 cm although some populations never attain more than 2-3 cm, and the largest specimens may reach 15 -20 cm. Mussels mature when one year old and may live 10-15 years or more. The breeding season is between April and September, with larvae settling after 1-6 months. Distribution: Very common all around the coast of the British Isles, with large commercial beds in the Wash, Morecambe Bay, Conway Bay and the estuaries of south-west England, north Wales, and west Scotland. Typically feeds on bacteria, phytoplankton, detritus, and dissolved organic matter (DOM).
Stock information
Criterion score: 1
info
Stock Area
UK
Stock information
No assessment of stocks by ICES in North East Atlantic. It is a non-pressure or unprotected species, i.e. not subject to quota restrictions. Wild mussel fisheries are found in tidal flats of the Wash, Morecambe Bay, Solway and Dornoch Firths in Scotland and river estuaries such as Conwy, North Wales and the Teign and Taw, Devon. The commercial development of natural beds is hampered by sporadic and unpredictable recruitment. There has been a move away from exploitation of wild stocks to cultivation in Britain. Cultivated beds are generally privately owned.
Management
Mussel beds are managed locally. Bylaws may limit the minimum landing size of mussels, e.g. in the Wash in England a local bylaw prohibits the landing of mussels below 5cm in length. Some regions have closed seasons to protect the breeding stock, for example, the River Dart fishery in Devon is closed from the 1st April to 30th September each year.
Capture Information
The main methods of harvesting for wild and farmed mussels are dredging and hand-gathering. Hand-gathering is a more selective and sustainable method of harvesting mussels in the wild, and causes less disturbance than mechanical methods.
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, 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
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.