UNDERSTANDING THE STRUCTURAL AND CHEMICAL BASIS OF OYSTER CEMENTATION

Oysters cement themselves together in order to construct extensive reef communities.  These collections of shellfish have a major impact on coastal ecosystems, being responsible for filtering water, holding sand in place, providing habitat for other species, and absorbing storm surge energy.  Oysters are also a major source of food.  In terms of aquaculture, we tend to prefer single oysters instead of clusters of the animals cemented together.

Our laboratory is working to understand the basis of how these shellfish can attach to surfaces and each other.  We are using methods including microscopy, biochemistry, chemistry, and spectroscopy.  Recent results include observations showing that the cement lacks microstructure, in contrast to the shell.  Other organisms and particles from the surroundings are trapped within this glue.  The composition of oyster cement is quite unusual for an adhesive, being mostly inorganic calcium carbonate with only a small fraction of organics.  Oxidative cross-linking of the organics appears to be present, explaining the insolubility of the material and some of the difficulties regarding detailed characterization.  Ongoing efforts include identification of the organic, biochemical components of this intriguing biological material.

Acknowledgment:  This work was supported by the Office of Naval Research.