Shellfish in Salem Sound
Salem Sound has shellfish resources: soft shell clams, quahogs, surf clams, razor clams, blue mussels, American oysters and European oysters, but NONE can be harvested for human consumption!
Shellfish are bivalve mollusks that filter the surrounding water for food, which is plankton, but microbial pathogens and biotoxins from algal blooms plus heavy metals are also retained in their body parts - the parts people like to eat. Clams, oysters and mussels have two muscles, while scallops have one muscle used for "swimming." We only eat the central muscle of American sea scallops (not the digestive tissues) so these are actually edible from Salem Sound.
For human health and safety, shellfishing harvesting is regulated by the FDA's National Shellfish Sanitation Program and the Massachusetts Shellfish Sanitation Program. Harvested shellfish must come from clean water or be processed in a certified shellfish purification plant prior to consumption.
The table below shows the fecal coliform (an indicator of bacteria coming from mammal guts) standards for approved shellfish beds, restricted shellfish harvesting, drinking water, swimming and boating.
Waters Impaired for Pathogens
Because Salem Sound is listed as Category 5 for pathogens - bacteria (impaired, and requiring one or more TMDLs and not supporting one or more intended use), it is included in the March 2012 Pathogen TMDL for North Coastal Watershed (43 segments). The Massachusetts Department of Environmental Protection (MassDEP) is responsible for monitoring the waters of the Commonwealth, identifying those waters that are impaired, and developing a plan to bring them back into compliance with the Massachusetts Water Quality Standards.
Salem Sound Coastwatch's mission is protect and improve the environmental quality of Salem Sound and its watershed. We take clean water very seriously and have been working for the past 25 years to improve the quality and reduce bacterial pollution sources. We have made great strides but work still needs to be done so we don't have to ask the question:
When will the day come that shellfish in Salem Sound can be legally harvested?
How Many Clams Does Salem Sound Have?
The last study to estimate the clam resources of Salem Sound was conducted by the Division of Marine Fisheries in 1997 and is written up in Technical Report TR-6, MA DMF, DFWELE, EOEA. by Brad Chase, J. Plouff, and W. Castonguay Chapter 4.
Soft-shell Clams need to be located in areas protected against waves and boat wakes. They prefer sandy sediment to sediments of silt and clay and
survive in intertidal and subtidal areas (up to 199 meters in depth) and where salinity is between 10-33 ppt (Newell, 1986).
Quahogs, which once served as a form of Native American currency, burrow into muddy and sandy sediment, with the northern quahog occupying shallower waters than the ocean quahog. Both require areas with moderate tidal movement, adequate dissolved oxygen levels and dense concentrations of plankton.
Razor clams also live in intertidal and subtidal areas and burrow into fine- to medium-grain sand and muddy sand (without silt). They can live in dynamic areas with unstable substrates.