In addition to being a valuable commercial and recreational food product, all of the shellfish that we grow and disseminate act as mini water filters (1 adult oyster can filter upwards of 50 gallons of water each day, clams filter at about half that rate). As filter-feeding animals, they are constantly pumping water through their bodies thus processing and sequestering the organic nutrients found in it as their food source. In excess, some of these organic nutrients (Nitrogen and Phosphorus for example) are responsible for causing harmful algal blooms in our harbors and bays.
According to Dr. Michael Rice from the University of Rhode Island, 3,750 growing oysters are capable of eliminating the nitrogenous waste from 1 person/year. A large healthy shellfish population can assist with the removal of contaminants and ultimately improve water quality which in turn benefits other denizens of the estuary such as eelgrass.
Concurrently the act of culturing shellfish and their subsequent presence in their natural habitat creates much needed structure for nursery finfish, shrimp, tunicates, macroalgae, etc.