First Atlantic Coast Offshore Mussel Farm In Federal Waters

Deploying mussel growout lines offshore

In August of this year, we began setting up the first 400ft mussel longline and deployed seed mussels for grow out in October.  We expect to harvest these mussels in early summer of next year.  This site is the first offshore shellfish farm in federal waters on the Atlantic Coast.  This is preceded by the establishment of the first offshore shellfish farm off California, Catalina Sea Ranch earlier this year.

In January 2015, the Northeast Massachusetts Aquaculture Center (NEMAC) at the Cat Cove Marine Lab obtained an Army Corps of Engineers (ACOE) permit ( NAE -2012-1598) to establish an offshore blue mussel (Mytilus edilis) long line aquaculture farm covering 33 acres, 8.5 miles off Cape Ann, Massachusetts. This permit is the culmination of a NOAA Fisheries grant received by Salem State biologists Mark Fregeau and Ted Maney in 2012 to permit and establish offshore shellfish aquaculture in federal waters.  This is only the third permit issued for offshore aquaculture in the US and the second off Massachusetts which was also the result of the NOAA grant.

Our project involves determining the feasibility of offshore shellfish aquaculture as a viable alternative to the depressed New England commercial fishing industry. Our first objective is the set up a small-scale pilot farm with the deployment of 2 - mussel longlines. This pilot farm will allow researchers to correlate environmental data with actual measurements of shellfish growth and survival, key parameters in determining the commercial potential of offshore habitats. We will evaluate gear options focusing on user-friendly designs, specifically for stocking, deployment and harvesting of mussel lines. The project will also develop stocking protocols to maximize mussel yields through refinements of seed density and line placement within culturing systems. Finally, the project will compare results with similar southern initiatives currently underway off Martha’s Vineyard, MA and in Narragansett Bay, RI.  The resulting data will provide a basis for best practices for offshore shellfish aquaculture.

Over the past 8 years, we have investigated the potential for culturing the blue mussel, Mytilus edulis, subtidally on long lines near coastal waters off Gloucester and Rockport, in conjunction with local fishermen. However, coastal waters, are crowded with numerous user groups making access to acceptable shellfish areas increasingly difficult. In many approved areas space is often the limiting resource for shellfish aquaculture. Culturing blue mussels offshore allows fishermen to avoid these space issues.

Open ocean mussel culture would avoid conflicts with other coastal fishing activities while providing new sources of income to fishermen and other fishing-related businesses in the ports along the New England coast. Our primary objective is to refine and enhance offshore mussel culture as an alternative fishing option for fishermen and lobstermen currently displaced or negatively impacted by current fishery restrictions.

Once established, we hope to engage and train local fishermen in the long-line mussel farming using our site as an incubator farm. Using an offshore mussel farm business plan developed by researchers at Woods Hole Oceanographic Institution, at full scale, the site will consist of 32 – 400 ft submerged longlines with 100 – 25ft socked mussel grow lines hanging off each longline. After growing for about a year, at harvest size, each 400ft longline should produce a yield of about 15000 lbs. of mussels.

The potential advantages of long-line shellfish production in offshore waters are many:


  • Limited impact on local habitats.
  • Complement shore-based shellfish harvest.
  • Multiple lines may be deployed in coastal and off-shore sites with minimal impacts to other maritime activities, such as other fisheries and recreation.
  • Fishers may supplement traditional fishing activity with open water shellfish harvest, providing a new way to use their boats.
  • Lines can be seeded with hatchery-reared and wild caught seed, reducing fishing pressure on natural shellfish populations.
  • Filtering activity of mussels can enhance water quality by removing excess organics. 


Project Personnel: 

  • Mark Fregeau and Ted Maney; Co-PI's
  • Captain Bill Lee, FV Ocean Reporter