Mussels: Farmed

Sea mussel, Blue mussel; Mediterranean mussel; Green mussel; New Zealand mussel

The most common culture species of mussel in Europe and North America is the Blue mussel (M. edulis) with most of the world’s Blue mussel production in Europe. In North America, the range of the blue mussel extends from the Canadian Maritime Provinces southward to Cape Hatteras, North Carolina in the United States. In the southern hemisphere, these mussels can be found in the waters off the coasts of Argentina, Chile, the Faulkland Islands, and the Kerguelen Islands. Other major aquaculture mussel species are in the genus Perna and include P. viridis (Asian green mussel), P. perna (brown mussel), and P. canaliculus (New Zealand mussel).
Life history traits of mussels that make them suitable for aquaculture include high fecundity, rapid growth rates and free-swimming larvae able to achieve wide distributions. Mussels tolerate crowding well, and they can settle and thrive at extremely high densities on suitable substrata. Mussels are also not as susceptible to parasites and disease organisms as oysters and other cultured bivalve species. Mussels are efficient filter feeders removing particles as small as 2 to 3 microns from water with 80% to 100% efficiency. Bacteria, phytoplankton, fine organic detritus, and material of inorganic origin are utilized as food. Mussels, like other bivalves, are preyed upon by a number of crab, starfish, fish, and bird species.

Formulated feed is not used in grow-out of mussels, thus fishmeal and fish oil are not used. In few cases mussels are produced in hatcheries, and cultured algae are used as food for mussels. Mussels rely on natural organisms and other non-living organic matter in the grow-out stage, thus removing nutrients from the water column. The use of marine resources, therefore, ranks “low” for cultured mussels.

Mussels consumed in the United States are native to the regions in which they are cultured. Because the majority of mussels imported into the U.S. are from countries using longline or raft culture techniques (suspended), the area under culture is relatively small and the activity is concentrated. Thus, the impact on wild mussels is small. Furthermore, because spat are harvested from the wild and not genetically manipulated, any escapes that do occur would not cause the genetic integrity of wild stocks to be compromised. Thus, as with all other forms of bivalve culture the risk of wild stock detriment by escape of culture species ranks “low”.

There are few incidences of disease outbreaks among mussels, and little evidence of cultured mussels threatening native stocks. Thus, the risk of disease transfer from cultured mussels to wild mussels ranks “low”.

The grow-out of mussels is accomplished in the natural environment, thus there is typically a beneficial effect on water quality in the culture area. However, some localized effects have been observed when mussels have been at very high biomass densities. Presently, the risk of pollution and habitat effects is therefore ranked “low” for off-bottom or suspended cultured mussels.

Mussel producers in the United States, Canada, and New Zealand are held to strict food safety and environmental regulations. As shellfish producers promote their industry as environmentally friendly, it is understandable that they attempt to go above and beyond recommendations and regulations for food safety and environmental health. At this time the management regime is deemed “highly effective”.

Are these mussels farmed or wild-caught?

Contaminant levels do not warrant a consumption advisory. + Available data are insufficient to assess contaminant levels in this seafood.