IT'S A CONSTRUCTION PROJECT:  LESSONS LEARNED FROM TWO DECADES OF HATCHERY-BASED OYSTER RESTORATION IN MARYLAND  

Chesapeake Bay contained the largest population of the Eastern Oyster Crassostrea virginica in the world but two centuries of overharvest, habitat destruction, environmental change and disease led to estimates of the Maryland populations being approximately 1% of historic levels.  The collapse of the resource and the industry it supported, along with the economic and social benefits provided to rural communities, led to numerous efforts to restore healthy reefs and reverse the trend.  However, formerly successful practices no longer produce reliable results and have not resulted in enough oysters to achieve restoration goals.

In 1992 Maryland Department of Natural Resources convened the "Oyster Roundtable" and charged its forty member panel with developing new and innovative methods to restore healthy populations.  Since the task force concluded its work, members have actively developed wide-ranging improvements in restoration that have led to major advances in cost-effective reef renewal.  Hatchery-based methods have been analytically compared to traditional techniques with comparisons illustrating important components that were previously ignored.

An important development has been the recognition of reef restoration as a construction project, with interconnected parts that include ground assessment, foundation design and emplacement and layering of seed at recognized densities to effect substantive biomass.  When Maryland began issuing new leases under a revised program in 2010, these lessons were transmitted to the aquaculture industry to more effectively choose grounds and provide better management leading to higher profitability.  The concepts and principles learned from two decades of intensified restoration have been applied to both public and private oyster production and shared with other geographic locations interested in advancing similar goals.

This paper discusses historic techniques and compares them with science-based approaches currently in use.  While advances in reef restoration techniques are often viewed as applicable only to sanctuary or ecologically-driven projects, data gathered during their assessment demonstrates the utility of these new construction techniques to those engaging in spat on shell oyster production on submerged land leases.