Blue Mussels

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Introduction

Blue mussels, the variety sold widely in grocery stores and fish markets, are available year round. The industry is concentrated in Prince Edward Island, but mussel farms are flourishing in Newfoundland and Labrador, New Brunswick, Nova Scotia, Quebec and British Columbia. In 2003, 20 510 tonnes of blue mussels were produced in Canada at a value of C$30.7 million.

Basic description

Cultured blue mussels, or Mytilus edulis, are a bivalve shellfish (an animal with two shells). Blue mussels have smooth, equally-shaped, bluish-black "D" shaped shells that are linked together on one side by a hinge. The inside of the shell is pearly violet or white. The meat inside the shell can be a creamy colour, pink or orange. Projecting out from between the shells on one side is a bundle of tough, brown fibres called byssal threads, more commonly known as the beard. Mussels use these fibres to anchor themselves to stationary objects.

The cold waters of the north Atlantic and Pacific oceans provide the ideal habitat for blue mussels. Cultured mussels do not touch the ocean bottom and feed off the nutrient-rich water that surrounds them. They taste sweeter, are plumper, more tender, have thinner shells, and yield a higher amount of meat than their wild counterparts. They are also free of the grit that often spoils the taste of wild mussels harvested from the ocean floor.

Background

Like most bivalve shellfish, blue mussels are filter feeders. They eat by pumping and filtering water through gill filaments which filter out small particles such as phytoplankton, zooplankton and other organic material. Mussels obtain all of their nutritional requirements naturally from the marine environment and do not require additional feeding. The rate in which they grow depends on location, water temperature, and the availability of plankton.

The average market-size blue mussel is harvested when it reaches 5.5 cm to 6 cm (2-2.5 inches) in length. Cultured mussels reach market size within 18 to 24 months following the transfer of the mussel seed or spat to the grow-out mussel socks. A sock is a long mesh tube that is suspended either from rafts or longlines near the surface.

When properly sited and designed, shellfish culture operations generally cause a minimum of change to the marine environment. Suspended culture allows mussels to be harvested easily when they reach market size. Cultured mussels can be harvested anytime throughout the year, but most of the harvest activity occurs between October and June.

For more information

An Economic Analysis of the Mussel Industry in Prince Edward Island

• This study was prepared by the Policy and Economics Branch, Gulf Region, Fisheries and Oceans Canada (June 2006). It is a comprehensive review of the Blue mussel aquaculture industry's contribution to the Prince Edward Island economy. It provides detailed information on: mussel operations; areas of production; value, production levels and export; as well as the challenges that tunicates or sea squirts, an aquatic invasive species, are posing for PEI's farmed mussel industry.
   
• Invasion of the Sea Squirts

Profile of the Blue Mussel

• Prepared by the Policy and Economics Branch, Gulf Region, Fisheries and Oceans Canada (February 2003). It provides information about the general characteristics of a Blue mussel, mussel harvesting methods, mussel aquaculture management, statistics (value, production and exports) and lists some of the Gulf Region's aquaculture and bivalve shellfish research and education programs.

Mussel Culture in Prince Edward Island

• Fact sheet prepared by PEI's Department of Agriculture, Fisheries and Aquaculture

Seafood Industry: Year in Review 2005

• Produced by the Department of Fisheries and Aquaculture, Province of Newfoundland and Labrador

Newfoundland Blue Mussels

• Fact sheet prepared by the Newfoundland Aquaculture Industry Association

Nova Scotia - Aquaculture Species Sheet on Blue mussels

• Fact sheet prepared by Nova Scotia's Department of Fisheries and Aquaculture

Blue mussels and polyculture research across Canada

• Polyculture, or integrated aquaculture, is the idea of growing finfish, shellfish and marine plants together for the benefit of all crops and the environment. Canadian researchers are studying various aspects of this new integrated model that involves the rearing of blue mussels and kelp near pre-established Atlantic salmon aquaculture sites in New Brunswick and British Columbia.