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Center for Coastal Resources Management

Pre-Cast Reef Structures

  • Oyster Castle
      Pre-cast concrete structures currently being used for living shoreline reefs include Oyster Castles® which are inter-locking blocks that can be arranged in different ways.  
  • Reef Ball
      Reef Balls are another pre-cast concrete product being used to construct oyster restoration reefs and living shoreline reefs.  
  • Ready Reef
      Ready Reef is a pyramid-shaped pre-cast concrete structure being used for living shoreline reefs.   Ready Reef
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Various manufactured products can be used to create an artificial reef foundation that supports the settlement and growth of shellfish.  Individual units are typically placed close together similar to a stacked shell bag or marsh sill structure. 

Suitable Sites
  • Evidence of healthy native shellfish population in vicinity, e.g. oyster beds &/or ribbed mussels
  • Salinity always above 10 ppt; sites with salinity below 5 ppt are not suitable for growing oysters
  • Water depth at least 1 foot at low tide; intertidal reefs are subject to freezing and winter die-off
  • Firm bottom, not soft mud
  • Suitable access to deploy and remove reef structures is available
Guidelines for Pre-Cast Reef Structures
  • Use marine-safe concrete structures that encourage shellfish to attach or settle
  • Include tidal gaps if the height of a continuous reef exceeds the mean high water elevation and the reef is adjacent to a natural or planted tidal marsh
  • Reef structures should be monitored for shifting and displacement from original permitted location
  • Promptly remove failed or damaged reef structures