Log in links for this page

Resources on contaminated shellfish harvest

Growing areas with consistent levels of contamination are not classified as Approved. Thus, shellfish from these areas can not be sold straight to market.

In growing areas that are not classified as Approved, the Division of Marine Fisheries (DMF) provides special permits to allow commercial harvesters access to those resources. DMF manages contaminated softshell clams through depuration and other shellfish through relay programs. A bait fishery for surf clams in Prohibited areas is also managed by DMF.


If you harvest contaminated soft shell clams, you must bring them to our Shellfish Purification Plant for depuration. The depuration process occurs for a minimum of three days and upon completion, the clams are returned to the harvesters. The purified clams are then sold in commerce.

To harvest contaminated soft shell clams, you must have either a Master Digger or Subordinate Digger license. Subordinate Diggers must work for a Master Digger. If you are interested in applying for a license, please contact our Boston office. 

Additional Resources


DMF allows municipalities to move 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 3 months and for the duration of 1 spawning season. Shellfish are tested prior to relaying and tested again before they are harvested for eating to make sure that they meet NSSP requirements for safety. 

To apply for a shellfish relay license, contact our New Bedford office. 

Additional Resources

Contaminated bait

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

If you'd like to apply for a contaminated surf clam dredge permit, complete a DMF commercial saltwater fishing permit and submit to the Boston office. 

Additional Resources

Contact   for Resources on contaminated shellfish harvest

Help Us Improve Mass.gov  with your feedback

Please do not include personal or contact information.