Seafood guides quicktabs
- Seafood Profile
- Biology & Habitat
- Science & Management
- Conservation Criteria
- Sustainability Summary
Blue mussels are the most widely consumed mussel in North America. Mussels are sold live and frozen as whole cooked, meats, and cooked on the half shell. Buyers should adopt a seasonal strategy because meat content decreases dramatically after mussels spawn: blue mussels are at their peak in winter and early spring while Mediterranean mussels are better in the spring, summer, and fall. Generally, rope-grown mussels have thin, clean shells and high meat content. Some producers hold mussels in tanks of water that are treated with ultraviolet light which destroys harmful bacteria, a process known as "depuration."
Health & Nutrition
- Total Fat4.48g
Blue mussels are usually a mix of colors, ranging from purple, blue, black, and brown, with occasional dark brown to purple radial markings. Their shell interiors are pearl-white with a wide border of purple or dark blue. They can reach lengths of 2-4.5 in (6-11 cm) and live an average of 12 years but can live up to 24.
Blue mussels are ecologically important in coastal ecosystems and are considered to be “ecosystem engineers,” as the dense beds provide shoreline protection and important habitat and shelter for a number of species. Blue mussel abundance has been positively correlated with overall species richness. They are semi-mobile suspension feeders, feeding on phytoplankton like green algae, dinoflagellates, and diatoms. As filter feeders, they help remove pollutants from the water. Blue mussels are also an important food source for other species, like sea stars, sea urchins, crabs, lobsters, whelks, fish, and birds.
General onset and length of the spawning season can vary temporally and spatially depending on latitude and is also directly driven by food availability and temperature. In the US, blue mussels spawn in the spring and summer. Blue mussels have high fecundity, producing between 50 and 200 million eggs per spawn. They grow quickly and have a mobile free-swimming larval phase that contribute to the development of mussel culture. The larvae resemble a miniature clam. Blue mussels first mature as males and later develop female reproductive capabilities. As a planktonic juvenile, they are vulnerable to predation from jellyfish and larval and adult fish.
Wild blue mussels are widely distributed globally, from the Arctic to the North Pacific and to the North Atlantic. In North America, they can be found from Labrador, Canada down to North Carolina, with the population centered in Maine. In Europe, they range from the White Sea, Russia to as far south as the Atlantic coast of Southern France.
Blue mussels generally inhabit brackish intertidal areas in sheltered areas, forming dense aggregations on hard surfaces. They attach to surfaces and each other with strong byssal threads. In other areas, they can also be found within silty or sandy substrate and eelgrass beds, on top of eelgrass beds, and in mixed sediments with gravel. They can be found in depths ranging from 0 ft to 196 ft (0 m to 60 m) and in subtropical areas with a preferred water temperature of 48°F (9°C). In general, they can withstand large fluctuations in salinity, desiccation, temperature, and oxygen levels, and thus can be found in a broad range of habitats. However, their distribution is controlled by biological factors such as predation and food competition. Where predators are lacking, blue mussel beds can reach up to 4 ft (1.2 m) thick and individual mussels can grow large in a relatively short amount of time.
Blue mussels are harvested both wild and farmed. There is only limited monitoring of US populations and abundance, and fishing mortality levels are unknown. There are no current efforts in place by state management bodies to monitor blue mussel populations. Reliable catch data are not available for Massachusetts or Rhode Island. However, fishing effort in Massachusetts, New York, and Rhode Island is low, so abundance is assumed to be high.
In the Gulf of Maine, a number of independent studies have studied blue mussel abundance. One study compared current abundance levels to historical estimates and found that blue mussels have declined an average of over 60% over the past 40 years. Maine fishery managers also report declines statewide between 2012-2017. Reasons for the decline is unknown, but are possibly due to warming water temperatures, green crab predation, overfishing, and increasing ocean acidification. The Maine Department of Marine Resources is currently working on a survey in the Jordan River in Frenchman’s Bay to sample the population with drones. This could potentially be used to conduct stock assessments in the future; however, this work is still in the preliminary stages.
Massachusetts currently has efforts underway to summarize the population status. The Center for Coastal Studies recently completed shellfish surveys in Pleasant Bay to establish a baseline of abundance.
New York has made little to no effort to track population trends because of their assumed healthy distribution and low fishing effort. Despite this limited scientific monitoring, commercial catches are monitored, and some management exists.
There is low demand in Rhode Island to evaluate the blue mussel population because fishing effort is very low. The only reliable catch information is in value and not quantity. There is spatial management in place to conserve the wild population. Recent efforts have been directed towards the growing aquaculture industry, evaluating shellfish disease and growing methods.Management:
There are wild US fisheries in Maine, Massachusetts, New York, and Rhode Island for blue mussels. Maine accounts for the majority of catch in the US. Blue mussels are caught in the winter before the spawning season, when their meat is considered to have the best market value. Commercial catch levels have historically fluctuated but is currently at low levels relative to other shellfish species. In Maine between 2000-2015, annual landings averaged 17 million pounds. The highest landings recorded were in 1995 at 37 million pounds. Massachusetts, New York, and Rhode Island have comparatively smaller-scale fisheries. They are harvested with hand rakes but 95% of the time are harvested with boat dredges.
Wild blue mussels are managed at the individual state-level by the Maine Department of Marine Resources (MDMR), Massachusetts Department of Marine Fisheries (MADMF), New York Department of Environmental Conservation (NYSDEC), and Rhode Island Department of Environmental Management (RIDEM).
In Maine, licenses are required to commercially fish for blue mussels, and landings cannot be combined with other shellfish. Fishers must tag them with the following information:
- Fisher’s name
- License number
- Date and time of catch
- Catch location
- Quantity of mussels
MDMR first put regulations in place for blue mussels in 1988 in an effort to protect wild populations from aquaculture efforts. Regulations also restrict mussel drags to have a maximum width of 6.5 ft, and fishing with gear is restricted between sunset and sunrise. There is no daily or annual catch limit for those who fish by hand or with a drag.
In Massachusetts, towns that border the coastal waters are given the authority to control and regulate the take of any kind of shellfish. However, MADMF has the authority to regulate shellfish taken from contaminated areas. Town regulations include:
- Daily limits
- Size limits
- Gear restrictions
- Temporary and seasonal closures
Harvesting blue mussels by hand rake in New York requires a NYSDEC permit and is also subject to a town permit depending on the town. A specific permit is required when using a dredge, which also has a daily catch limit. Fishing for shellfish is allowed year-round, but only during daylight hours and in designated areas.
Specific permits are also required to harvest blue mussels with dredges in Rhode Island. State agencies, the fishing industry, and stakeholders developed the Shellfish Management Plan in 2014 to establish Shellfish Management Areas to conserve and rebuild shellfish resources. This plan puts catch limits on commercial fishing within these Management Areas and no limits outside.
Blue mussels are also farmed globally, on both coasts of North America, in Europe, Canada’s Prince Edward Island, China, and South America. Because they are filter feeders, feed is not required to grow them and thus there are no effluent concerns. Mussel farming in fact increases water quality at farming sites by removing excess nutrients and phytoplankton. Farming operations are typically located in intertidal and shallow subtidal environments, as well as in waters deeper than 66 ft (20 m). Farming operation impacts on the habitat are considered minimal.
Mussel culture generally does not require chemicals such as antibiotics, pesticides, herbicides, and fertilizers to control fouling, predators, or disease. Production for farmed mussels include on-bottom or suspended culture. Suspended culture is more common as it allows for quick growth, low predation, and reduced sand accumulation. There are no safeguards for larval escape due to unrestricted broadcast spawning, so for those mussels that are cultured in their non-native ranges, these recipient ecosystems have been impacted through resource competition and habitat modification.
Stock for farmed mussels comes from active collection via dredging, natural settlement, and passive settlement. Hatcheries are seldomly used to supply seed but have been employed by China since the 1970s. Most recently, the US Pacific Northwest has begun to use hatcheries as well.
In 2016, the US produced 894,000 pounds of mussels, valued at $10.48 million. Maine is the largest US farmed blue mussel producer, and Washington is the West Coast’s major producer. US blue mussel aquaculture is federally managed by:
- Army Corps of Engineers
- Fish & Wildlife Service
- US Department of Agriculture
- Environmental Protection Agency
- Food and Drug Administration
- Bureau of Ocean Energy Management
- Coast Guard
Aquaculture farms must follow regulations outlined in the Magnuson-Stevens Fishery Conservation & Management Act, the Endangered Species Act, the National Environmental Policy Act, and the Clean Water Act.
Impact on Stock
Declines in the Maine fishery have been reported, but abundance is assumed to be high in the Massachusetts, New York, and Rhode Island fisheries. In general, fishing levels relative to a sustainable level are unknown. All states have some regulations in place to control fishing rates.
Mussel dredges cause more damage to the bottom habitat than hand rakes, but most states have measures in place to limit gear impacts. Relative to other dredging gear, mussel dredges are smaller and not hydraulic. These differences have less of an impact on the bottom substrate. Dredging usually occurs over intertidal and subtidal mudflats in nearshore bays. While the bottom sediment is mainly mud, some sand and shells can be mixed in. These nearshore bays may also be adjacent to or interspersed with eelgrass, which can be uprooted and damaged during dredging. Overall, dredging can disturb bottom flora and fauna, water quality, adult mussels and seed mussels, bay drainage, and food for birds and other organisms.
Fishers use both hand rakes and mussel drags or dredges to harvest blue mussels from their dense beds. Hand rakes allow fishers to selectively target the mussels. Bycatch is typically low and does not regularly include threatened, endangered, or protected species. When using hand rakes, most non-targeted species are returned unharmed, so the effects are negligible.
Impacts in the dredge fishery are more uncertain. Non-target species are still reported in low levels but can include bottom dwelling fish and other benthic invertebrates such as worms, sea urchins, crabs, and starfish that live among the mussel beds. These species are returned but may be harmed during the process. However, mussel dredges are size-restricted and the fishery is selective for mussels.
Some spatial management policies are in place to help protect blue mussels’ ecological role, but more robust policies are necessary to reduce negative ecosystem impacts from fishing.
In Maine, the MDMR designated four seed conservation areas from which only seed-size mussels can be taken for grout. This is intended to help reduce conflict between the wild mussel fishery and expanding aquaculture industry. Massachusetts, New York, and Rhode Island show no evidence of declines or overfishing despite the lack of population monitoring.
Mussels are often raised on ropes submersed in coastal areas, a system considered to be one of the most environmentally friendly forms of aquaculture. They are also bottom cultured and harvested by dredging, which can degrade sediment and cause a decline in biodiversity. However, dredging cultured beds causes less damage than dredging natural ones. Although they are filterfeeders that improve water quality, mussels will only thrive in a healthy environment. Harmful algal toxins in the water have caused some mussel farming areas to be closed temporarily.
Mussel farms tend to be protected from duck predators with fine mesh that is heavily weighted to avoid problems there with entanglements.
Mussels are filterfeeders that take in plankton so no extra feed is needed to grow them.
Disease, Pathogen and Parasite Interaction
Disease incidence among mussels is low.
Escapes and Introduced Species
Mussels are generally farmed in areas where they are native and interbreeding between wild and escaped mussels doesn’t threaten the wild populations. Mediterranean mussels farmed in the U.S. are considered a naturalized species.
|Origin||Harvest Method||Sustainability Ratings||FIP Source|
|Chile||All Farming Methods|
|Chile (ASC)||Suspended Culture|
|Chile (ASC)||On-Bottom Culture|
|Denmark - Inner Danish Waters (MSC)||Boat Dredge|
|Denmark - Limfjord (MSC)||Boat Dredge|
|Denmark - Limfjord (MSC)||Suspended Culture|
|Germany - Lower Saxony (MSC)||Boat Dredge|
|Germany - Lower Saxony (MSC)||Suspended Culture|
|Germany - Wadden Sea (MSC)||Boat Dredge|
|Ireland (MSC)||Boat Dredge|
|Irish Sea (MSC)||Boat Dredge|
|Netherlands (MSC)||Boat Dredge|
|Sweden (MSC)||Suspended Culture|
|Unassessed Origin||Unassessed Fishing Methods|
|Unassessed Origin||Unassessed Farming Methods|
|United Kingdom||Suspended Culture|
|United Kingdom||On-Bottom Culture|
|United Kingdom (ASC)||On-Bottom Culture|
|United Kingdom (ASC)||Suspended Culture|
|United Kingdom (MSC)||Suspended Culture|
|United Kingdom (MSC)||On-Bottom Culture|
|United Kingdom - Cornwall||Suspended Culture|
|United Kingdom - Northern Ireland (MSC)||Dredge Harvest|
|United Kingdom - Northern Ireland (MSC)||Hand Rake|
|United Kingdom - Scotland (MSC)||Off-Bottom Culture|
|USA - Maine||Hand Implements|
|USA - Maine||Hand Dredges|
|USA - Maine (FIP)||Hand Dredges|
|USA - Maine (FIP)||Hand Implements|
|USA - Massachusetts||Hand Dredges|
|USA - Massachusetts||Hand Implements|
|USA - New York||Hand Dredges|
|USA - New York||Hand Implements|
|USA - Rhode Island||Hand Dredges|
|USA - Rhode Island||Hand Implements|
|A&R Seafood Company||United States||California|
|Allseas Fisheries Corp.||Canada||Ontario|
|American Mussel Harvesters||United States||Rhode Island|
|AquaPrime Mussel Ranch||Canada||Nova Scotia|
|Atlantic Aqua Farms Partnership||Canada||Prince Edward Island|
|Barry Group, Inc.||Canada||Newfoundland and Labrador|
|Catalina Offshore Products||United States||California|
|Catanese Classic Seafood||United States||Ohio|
|Clipper Ship, Inc.||United States||Washington|
|Codfathers Seafood Market||Canada||British Columbia|
|Conchyliculture Gloucester Shellfish Co. Inc.||Canada||New Brunswick|
|Confederation Cove Mussel Company||Canada||Prince Edward Island|
|DiCarlo Seafood Company||United States||California|
|DOM International Limited||Canada||Ontario|
|Euclid Fish Company||United States||Ohio|
|Export Packers Company Limited||Canada||Ontario|
|Imperial Seafood and Shellfish Inc.||United States||Ohio|
|Intercity Packers Meat & Seafood||Canada||British Columbia|
|Island Creek Oysters||United States||Massachusetts|
|Island Sea Farms, Inc.||Canada||British Columbia|
|J.P.'s Shellfish, Inc.||United States||Maine|
|John Nagle Co.||United States||Massachusetts|
|Lotus Seafood Inc.||United States||California|
|Lusamerica Foods, Inc.||United States||California|
|Macgregors Meat & Seafood Ltd.||Canada||Ontario|
|Maine Shellfish Company||United States||Maine|
|Marinelli Shellfish Co.||United States||Washington|
|Mariner Neptune||United States||Iowa|
|McRoberts Sales Co., Inc.||United States||Florida|
|Monterey Fish Market||United States||California|
|Northeast Oceans||United States||Massachusetts|
|Northwest Fresh Seafood Company||United States||Oregon|
|Ocean Beauty Seafoods LLC||United States||Washington|
|OM Seafood Company||United States||Oregon|
|Out Landish Shellfish Guild||Canada||British Columbia|
|Pacific Harvest Seafoods||United States||California|
|Pangea Shellfish Company||United States||Massachusetts|
|Pemaquid Mussel Farm||United States||Maine|
|Penn Cove Shellfish, LLC.||United States||Washington|
|Pike Place Fish Market||United States||Washington|
|Prince Edward Aqua Farms||Canada||Prince Edward Island|
|Profish Ltd.||United States||District of Columbia|
|Red's Best||United States||Massachusetts|
|Robbie's Ocean Fresh Seafood, Inc.||United States||California|
|Royal Hawaiian Seafood||United States||California|
|Sailor's Seafoods||Canada||British Columbia|
|Sammy's Seafood Inc||United States||Florida|
|Samuels & Son Seafood Company, Inc.||United States||Pennsylvania|
|Sarasota Seafood Company||United States||Florida|
|Sea Forager Seafood||United States||California|
|Sea to Table, USA||United States||New York|
|Seattle Fish Company||United States||Colorado|
|Seattle Fish Company - Kansas City||United States||Missouri|
|Smokey Bay Seafood Company, Ltd.||Canada||British Columbia|
|Sogelco International, Inc.||Canada||Quebec|
|Star Fisheries Inc.||United States||California|
|Stavis Seafoods||United States||Massachusetts|
|The Fish Guys Inc.||United States||Minnesota|
|The Fishin' Company||United States||Pennsylvania|
|The Lobster Man||Canada||British Columbia|
|The Lobster Place Wholesale Seafood||United States||New York|
|Thimble Island Ocean Farm||United States||Connecticut|
|Whitecap International Seafood Exporters||Canada||Newfoundland and Labrador|
|Wixter Market||United States||Illinois|
- Environmental Defense Fund
- Food and Agriculture Organization of the U.N. (FAO)
- NOAA Fisheries
- Seafood Watch Program