Only five species of oysters are harvested in the United States. Oysters are, of course, the great passion at Hog Island. More than any other food from the sea, oysters reveal the qualities of the ecosystem in which they were grown. Tides, salinity, temperature, plankton abundance, and ocean chemistry all combine to create what shellfish growers like to call the “merroir” of an oyster, the taste of place. These differences can be dramatic—even across relatively small areas.