Oyster Reef Ecology

Once valued primarily as a harvestable resource, oysters are now recognized as key elements of many estuarine ecosystems.  The eastern oyster, Crassostrea virginica, creates complex habitats utilized by fish, crustaceans, bivalves, and numerous other invertebrates and vertebrates (e.g. birds and mammals). 

During feeding, oysters can filter large quantities of water, improving water clarity and quality while transferring nutrients from the water column to the benthos.

Tank with oysters filteringOyster populations, once a dominant feature of most Atlantic and Gulf coast estuaries, have drastically declined in many areas across the U.S.  In the Chesapeake Bay, for instance, current oyster populations represent less than 1% of the historic resource.  Declines in oyster populations are associated with adverse effects on other species, reduced water quality and changes in ecosystem dynamics.

In South Carolina, as elsewhere in the southeastern U.S., oysters are primarily intertidal, i.e. exposed at low tide.

Although intertidal oyster reefs can occur in the middle of creeks and bays, where they are often called oyster "flats", a large percentage of our oysters occur along the margins of tidal creeks where they are referred to as “fringing” reefs.

SCDNR has been studying oyster reef development, documenting habitat function and value, and  studying oyster reef/shoreline interactions. In order to develop improved strategy for protecting, managing and restoring this critical resource.