Ecological Restoration

Oysters are currently at less than 1 percent of historic abundance due to disease-related mortality, habitat degradation, reduced water quality and harvest pressure. Based on recent scientific review of restoration alternatives for the native oyster in Chesapeake Bay, the ecological restoration team works with our many partners to optimize ecological benefits and enhance population recovery while minimizing costs. We work closely with our partners to rehabilitate degraded habitat using natural oyster shell and/or alternative substrates and to target the planting of disease-free hatchery oysters produced by our Piney Point Aquaculture Facility and the University of Maryland's Horn Point Hatchery. Please explore this page to learn more about our restoration activities.

Harris Creek Oyster Restoration
Notice: water depths are shallower than currently shown on charts.


Click on Map for more information.

Implementation Update: Harris Creek, Little Choptank River and Tred Avon River:
2015 Choptank Oyster Implementation Update
2014 Choptank Oyster Implementation Update
2013 Oyster Restoration Progress in the Choptank Complex

Maryland's 10-Point Oyster Restoration Plan

In order to achieve our oyster restoration goals, the State of Maryland is following a comprehensive 10-point restoration plan. The plan is outlined here, with more detail provided for items pertaining directly to restoration.  You may download a slideshow about therestoration plan here. You can view the entire 2010 regulatory package including statements of purpose published in the July 2, 2010 issue of the Maryland register here.

  1. Focus on targeted restoration strategies
  2. Expand the sanctuary program
  3. Support a more targeted and scientifically managed wild oyster fishery
  4. Shift commercial production to aquaculture
  5. Rehabilitate oyster bar habitat
  6. Manage against oyster disease
  7. Increase hatchery production
  8. Enhance law enforcement
  9. Increase citizen involvement
  10. Integrate inmate labor

Targeted Restoration

Maryland is implementing multiple strategies for native oyster restoration using a targeted approach. We will set goals to maximize ecological benefits, facilitate population recovery and create positive outcomes for the commercial oyster fishery. We combine recent bottom survey data, oyster population surveys and water quality data with historical oyster bar locations to help determine the best sites for restoration. Knowing the average salinity in a tributary allows us to select a restoration alternative that appropriately addresses disease and recruitment issues at each site. Although successful recruitment occurs in higher salinities, oysters there are subject to greater disease pressure. Conversely, oyster populations in lower salinities are recruitment-limited but benefit from the inability of disease-causing organisms to flourish there. Many partners, including federal and state agencies, non-profit organizations and educational institutions are involved in completing any one project.

Facing a Shell Shortage

Oyster shell, either new (shucked) or from buried deposits, is the predominant and preferred cultch for oyster habitat projects in the Bay. Since 1960, the dominant source of shells for restoration has been dredged shells from buried deposits in the Upper Bay; however, improving degraded oyster habitat across large areas will require more shell than is available from shell deposits. To obtain sufficient cultch for upcoming restoration projects, Maryland has obtained a permit for the collection and re-use of previously-planted shell. Initial efforts to recover this material have not proven cost-effective, however. Also pending is a shell dredge permit application to obtain up to an additional 5 million bushels of shell from Man o' War Shoal.

Alternative Substrates

Because of the shortage of oyster shell, Maryland is using alternative substrates to rebuild degraded oyster bars. Currently we are using clam shell, fossil oyster shell and granite to provide a firm base for the placement of spat on shell. These materials have proven effective not just as a base for spat on shell, but also for the settlement of natural oyster larvae.

Oyster Hatcheries

In order to meet the demands of an aggressive rehabilitation agenda, a rapidly growing Marylanders Grow Oysters program and a new commercial aquaculture initiative, Maryland must have access to large quantities of disease-free oyster larvae (up to 2 billion per year) for restoration and distribution. To this end, the Maryland Department of Natural Resources has done the following:

  • Established a new Memorandum of Understanding with the University of Maryland Center for Environmental Science for future hatchery production;
  • Purchased oyster shells from shucking houses in the state and transported them to the University of Maryland Center for Environmental Science Horn Point Hatchery;
  • Supported legislation that increased the price paid per bushel of oyster shell;
  • Initiated oyster production at its own Piney Point Aquaculture Facility in St. Mary's County.

Restoration Projects