Oyster reef restoration projects have been focused more on reversing the trend of inhibited areas than on rebuilding self-sustaining reefs to promote ecosystem health, functions and services. Oyster population dynamic, carrying capacity and ecological services in any given location depends on that location’s environmental conditions. For example, we had to provide a natural hard benthic substrates (cultch) to support naturally present oyster settlement (Wellfleet Harbor, Chesapeake Bay). However, in the areas where there is a limited or no existing oyster population, restoration was supported by the ‘spat on shell’ approach (Boston Harbor, Nantucket Island, Orleans Harbor). In addition, floating structures were used in the areas where benthic substrate was unsuitable (mucky), made from various materials (recyclable plastic, green cement). Type of environmentally friendly materials (based on Green Chemistry technologies) that we identified to be the most suitable to support oyster reef restoration include various green cements manufactured by BluePlanet Ltd, ECOncrete, and Growoysterreefs.

How many oysters are necessary to support healthy population and reef habitat? Based on the literature review, native reefs consisted of 5,895 oysters per square yard (Luntz, 1960). Therefore, we used this number to visualize and calculate the potential vast of oyster population, density and biomass, as well as carrying capacity in restored areas. For example, in the Wellfleet Harbor project, we established a two acre pilot site and in two years restored 6 million oysters, by placing tons of recycled shells (cultch) for oyster settlement. Restored population of oysters improved the local water quality in the harbor, the biodiversity, including fish and crustacean species, as well as improved sediment quality, and shoreline protection (www.umb.edu/GHP). How would nature restore oyster reefs?

Oysters have been an essential part of global coastal ecosystems and natural source of flux and nexus of food, water and energy between land and ocean. Biomimicking natural solutions is the most environmentally, economically and socially justified approach. A biomimicry-based approach to oyster habitat restoration will seek to ensure that infrastructures and activities are based on the six core principles: 

1) Does the new restored habitat (structure) have the capacity to evolve and survive? The goal is for the restored oyster communities to become self-sustaining in situ, evolving naturally, providing ecosystem services and functions. 

2) Is the restoration project resource efficient? The multifunctional design in oyster reef restoration uses a water-energy-food nexus process, established between the building structure, surrounding water, benthic communities, and other coastal habitats like salt marsh, kelp and SAV. 

3) How does the restored site adapt to changing conditions and model resilience? Resiliency of habitats and ecosystems attributes to their interconnectedness and interdependence, as living things adapt and evolve locally without waste of energy or materials. Collaboration is the driving force in evolution, not the competition.

4) Are development and growth integrated in the restoration process? Structural designs of oyster habitats are modular and nested within the water column and benthos, over time they integrate development and growth to self-organize to develop complex food webs and trophic interactions. 

5) How is the restoration locally attuned and responsive? The complex ecological functions provided by an oyster reef at the restoration site will need to be determined and incorporated in designing the coastal and marine built structures. 

6) Does the restoration use life-friendly materials, water based chemistry and self-assembly? This principle requires that structures are built by local, natural, untreated materials, sustainable, recyclable, not harmful to water and support conditions conducive to life. 

Adequate, healthy water quality is the most important factor supporting coastal habitats’ health, function and biodiversity. There are numerous missing ecosystem functions and services that oyster reefs can provide in polluted and degraded marine ecosystems, including bioremediation, specifically when addressing the impact and exposure to microplastic contamination and many infectious diseases that limit restoration efforts in marine environments.