Contaminated Shellfish Resources 

MarineFisheries directly manages the contaminated shellfish resources for depuration, relaying and bait.

Depuration: The management and oversight of soft-shell clams for depuration is a substantial activity for MarineFisheries. Clams are harvested from specially designated, conditionally restricted areas of Boston Harbor and transported by MarineFisheries licensed and bonded master diggers under strict enforcement to the Shellfish Purification Plant located on Plum Island in Newburyport. Once at the Shellfish Purification Plant, the clams are treated in a controlled aquatic environment and purified. The Shellfish Purification Plant is a state of the art facility containing nine depuration units. Pure seawater is obtained from two deep salt-water wells and is continuously disinfected using ultra-violet light. Depuration is a complex biological process requiring constant validation, during and upon completion of the treatment, through testing of shellfish and tank water. This is accomplished by daily testing in an on-site certified laboratory. The depuration process occurs for a minimum of three days and upon completion, the clams are returned to the harvesters, who pay a depuration fee. The purified clams are then sold in commerce.

The Newburyport Shellfish Purification Plant is the oldest and largest continually operating depuration facility in the country having been in continual operation since 1928. It's also the only publicly owned and operated depuration plant in the United States. The plant is open 364 days a year and processes an average of 560 bushels of soft-shelled clams a week.

Contaminated Relays: Under the relay program, MarineFisheries permits municipalities to relocate contaminated shellfish to clean waters for natural purification and propagation. Relays are conducted under stringent NSSP guidelines and are heavily supervised by state and local enforcement authorities. Contaminated shellfish must remain at the relay site for a minimum of three months and also for the duration of one spawning season. Shellfish are tested prior to relaying and again before harvesting for human consumption to insure that they meet NSSP requirements for safety. The northern quahog (Mercenaria mercenaria) is most often transplanted at around 14-18,000 bushels a year. Oysters and soft-shelled clams are also moved. Most contaminated quahogs are obtained from the waters of the Taunton River - Mount Hope Bay area and New Bedford, Fairhaven and Dartmouth. This method of shellfish propagation affords participating municipalities a relatively inexpensive source of shellfish for use as spawning stock and also allows eventual utilization of the contaminated resource thus eliminating the temptation of illegal harvesting by removing the stock from contaminated areas.

Contaminated Bait: Currently, the only contaminated shellfishery for bait is the heavily regulated, occasional surf clam dredge boat fishery. Recent activity has been minimal.

Surf Clam and Quahog Dredge Fisheries

Unlike other shellfisheries in non-contaminated waters that are under municipal control, the commercial harvest of surf clams, Spisula and ocean quahogs Arctica are under MarineFisheries control. Likewise, the harvest of northern quahogs Mercenaria using dredges in certain waters of the Commonwealth is managed by MarineFisheries through a limited access licensing process. This catch information is maintained in a multifunctional database which enables fishery managers to determine Catch per Unit of Effort (CPUE), measure impact of fishing in specific locations, conduct trend analysis and determine amount and value of landings. Much of this data is shared annually with the National Marine Fisheries Service (NMFS) and is incorporated into the total U.S. landings data. For a blank copy of both the surf clam and ocean quahog catch report form, click here .

Shellfish Statistics

MarineFisheries is charged with collecting, analyzing and maintaining an historical database of commercial and recreational shellfish landings. This information is initially collected by each of the 65 coastal cities and towns of the Commonwealth and submitted annually to us on "Town Landings Forms". Data collected reflects the number and types of permits issued, the pounds of each species landed and by what shellfishing methods. Along with data, the municipalities submit updates of their local shellfishing regulations. This data has been maintained since 1955 in both hard copy and electronic format and is used for fisheries management on the local, state and federal levels.

Technical Assistance

In Massachusetts, the cities and towns manage the shellfisheries in all waters within their boundaries that are not closed by MarineFisheries for public health reasons, with the exception of the commercial harvest of surf clams and ocean quahogs that remain under state control. One of our roles is to assist the municipalities concerning a wide variety of shellfisheries management issues by providing technical and regulatory information as well as advice and recommendations to local shellfish managers. Assistance is provided regarding shellfish propagation techniques, predator controls, shellfish survey methods, management openings and closures, habitat improvements, the development of shellfish management plans and shellfish aquaculture development and regulation.

Aquaculture Management

A major management and technical assistance endeavor of the Shellfish Program is the regulation of shellfish aquaculture. This activity involves two areas of concern; the licensing of sites by municipalities and the permitting of aquaculturists to obtain and possess sub-legal shellfish (seed) for transplant and grow-out to legal size. MarineFisheries municipalities by certifying after inspection of the project area, (as required by statute Chapter 130, Sec. 57;MGL) that license and operation will cause no substantial adverse effect on shellfish or other natural resources of the city or town. Aquaculturists are required to obtain a MarineFisheries propagation permit annually. Each permit is specific to the needs of the individual grower based upon a permit application. The purpose of this process is to control the introduction of shellfish diseases, non-native shellfish species and other pests or predators into Massachusetts's waters. About 300 propagation permits are issued each year. Other related activities include: assisting individuals in the licensing and permitting process, providing information on aquaculture to interested parties, assisting municipalities with site selection prior to formal site survey in order to avoid MarineFisheries denial, and assisting growers in finding seed sources and working with hatcheries to become certified to sell seed in Massachusetts.

Shellfish staff also assists the Southeastern Massachusetts Aquaculture Center (SEMAC) by reviewing proposals by aquaculturists for SEMAC funding. Recommendations and comments are made regarding each proposals appropriateness, feasibility and permitting requirements.

Environmental Protection

Shellfish Program personnel respond to pollution events in coastal waters in order to assess possible damage to shellfish resources and to determine the need for public health closures. These events include sewage discharges, boat sinkings, petrochemical spills and other discharges of hazardous chemicals.

In addition, the Shellfish Program co-reviews with other MarineFisheries staff various proposed coastal alteration projects with regard to impacts on water quality, shellfish resources and shellfish habitat. Recommendations are made through the MarineFisheries environmental review process to the permitting agencies concerning the effects of proposed structures, dredging, filling or discharges into the marine environment.