Oyster Reef Breakwater Restoration Project on Alabama’s Gulf Coast
Oyster reef habitat has disappeared from much of the Gulf Coast. These reefs absorb wave energy, protecting shorelines from erosion and providing habitat for a variety of wildlife. The Nature Conservancy in Alabama conducted a project to restore this habitat to two tracts of shoreline in Mobile County. This 2009-2012 project created jobs and stabilized currently eroding shorelines, which are threatened by rising sea levels and storm surge.
Storms, such as Hurricanes Ivan and Katrina, have degraded shoreline habitats along the Gulf Coast of the United States and caused major economic and job losses in coastal Alabama. The Nature Conservancy (TNC) in Alabama initiated an oyster reef habitat restoration project in Mobile County in 2009. Typical shoreline hardening measures in the area include structures like bulkheads, seawalls, and jetties, which are used to stabilize shorelines but can alter and degrade habitat as well. This project was designed to create a natural, “living shoreline” of Crassostrea virginica oysters in order to restore an economically and ecologically important habitat to the state’s coast.
Oyster reefs are three dimensional habitats and serve many ecological functions; they can reduce shoreline erosion, create habitat for other species (fish, crabs, birds), and improve water quality by filtering nutrients and sediments. This habitat has essentially disappeared from Alabama’s coasts as a result of overfishing, pollution, disease, and storms. Oyster reefs serve as natural coastal buffers to protect shorelines by breaking down wave energy, so restoration of this habitat can help protect the coast from the likely increases in storm surges and sea level rise expected with climate change. This project aimed to:
- restore oyster habitat and its associated ecological services;
- stabilize and restore approximately 1500 meters of shoreline; and
- create 30–40 fishery and restoration-related jobs for south Mobile County.
Three different restoration techniques were used at two locations in the state – Mobile Bay and Portersville Bay.
TNC received a $2.9 million, two-year grant from the National Oceanic and Atmospheric Administration through the American Recovery and Reinvestment Act (ARRA) to restore oyster habitat. With assistance from the Dauphin Island Sea Lab (DISL), Alabama Department of Conservation and Natural Resources State Lands Division, National Wildlife Federation, and countless volunteers, TNC used three different restoration techniques to create structures upon which oyster could seed and build over two acres of land. These techniques included bagged oyster shells, reef balls, and ReefBLK(SM) cages; each of these were placed along 500 meters of shoreline, totaling 1500 meters. Project leads also conducted physical and biological monitoring of the sites to measure success, and outreach to stakeholders, including the development of lesson plans for DISL’s K-12 and teacher training workshops, an outdoor restoration display, and outdoor signage near both reef sites.
Outcomes and Conclusions
Despite a four-month delay due to the April 2010 Deepwater Horizon accident, the project team created three acres of oyster reef along two miles of shoreline, and 30 acres of habitat for marsh and seagrass between November 2009 and September 2012. The project took approximately 50,000 man-hours to complete, created over 30 full-time jobs, and contributed to the paychecks of over 100 scientists, engineers, laborers (including local fishermen and others displaced by the Deepwater Horizon oil spill), and project coordinators in coastal Alabama.
The success of this project has spurred the creation of a long-term program to promote economic growth and coastal resilience in the region. The 100-1000: Restore Coastal Alabama Partnership aims to build 100 miles of oyster reefs and cultivate the growth of 1,000 acres of marsh and seagrass in order to:
- Provide habitat for oyster larvae;
- Serve as nursery habitat for commercial and recreational fish species (e.g., shrimp, blue crab, southern flounder);
- Buffer wave energy and shoreline erosion; and
- Stabilize sediments.
The Partnership includes over 40 public and private partners such as TNC-Alabama, Alabama Coastal Foundation, DISL, Mobile Baykeeper, The Ocean Foundation, University of South Alabama, and other local, state, and federal agencies.
While the 2009-2012 project is complete, TNC continues to maintain and monitor 10 living shoreline projects on the Alabama Gulf Coast. The TNC website includes information on these individual projects, as well as a report on the impacts of living shorelines in Alabama.
Gregg, R.M. (2021). Oyster Reef Breakwater Restoration Project on Alabama's Gulf Coast [Case study on a project of The Nature Conservancy - Alabama]. Version 2.0. Product of EcoAdapt's State of Adaptation Program. (Last updated May 2021)