With coastal military installations increasingly impacted by surrounding urban areas, climate change and sea level rise, the U.S. Department of Defense (DOD) is implementing ecosystem-based management (EBM) for long-term resiliency. NCCOS’ expertise in salt marsh response to sea level rise helped inform DOD on the best strategies for EBM at USMC Camp Lejeune. A recent publication, authored in part by NCCOS, summarizes the key elements of the Camp Lejeune initiative, its contributions to coastal EBM, and its relevance for employing EBM at other coastal military installations.
Large portions of many DOD installations harbor natural communities and have become refuges for threatened and endangered species. [Like all federal agencies, the DOD must meet environmental regulatory standards and laws, such as pollution and endangered species]. The military mission also depends on conservation of natural ecosystems and their key ecological processes to provide training realism.
The DOD Defense Coastal/Estuarine Research Program (DCERP) was a 10-year multi-investigator initiative to improve understanding of ecosystem processes and their interactions with natural and anthropogenic stressors at the Marine Corps Base Camp Lejeune (MCBCL), coastal North Carolina. The DCERP was aimed at facilitating EBM at the MCBCL and other coastal military installations. DOD contracted with NCCOS and other organizations to carry out the DCERP at MCBCL.
DCERP consisted of 19 research projects distributed among four ecosystem modules: Aquatic/Estuarine (rivers, creeks, and estuary), Coastal Wetlands (salt and brackish marshes), Coastal Barrier (island), and Terrestrial (pine and hardwood forests). To support the needs of these research projects, an additional research project focused on the development of uniform historical and projected patterns of climate change for this region.
NCCOS’ research contribution focused primarily on the coastal wetlands module. The results of the coastal wetland research provided a foundation for developing and testing adaptive management approaches to improve the sustainability and resilience of MCBCL salt marshes to SLR and erosion. The research showed that fertilizer additions resulted in short-term increases in marsh surface elevation, with the response moderated by inundation, and may increase marsh resilience to SLR in some settings. At sites with long inundation periods there may be no response to fertilization since accumulated sulfide inhibits uptake of nitrogen by the flora. Fertilizer addition may also not be appropriate at the edge of tidal creeks, as nitrogen additions can increase microbial decomposition and result in a five-fold increase in net carbon loss and erosion.
The findings led to a partnership with the U.S. Army Corps of Engineers to conduct pilot projects to test thin-layer dredged sediment application as a means to provide marshes with ‘elevation capital’ and increase resiliency to SLR. The response of low lying cordgrass (Spartina alterniflora) marsh to thin layer sediment additions in this pilot program matched model predictions based on field observation.
Recommendations for Coastal Wetlands on MCBCL included:
- When shoreline stabilization is required, a living shoreline approach with salt marsh habitat is preferred to shoreline armoring with hard structures.
- Buildings, roads, and other infrastructure should be located away from wetlands and shorelines to allow for migration of marshes and coastal protection from storm surge.
Key to the success of the DCERP was the use of a Technical Advisory Committees (TAC) and a Regional Coordinating Committee (RCC). The TAC, composed of scientists representing expertise in each of the ecosystem modules, ensured the quality of the science and the integration and synthesis across ecosystems. The RCC, which included representatives of city, county, state and federal agencies and nongovernmental organizations, provided input from stakeholders outside the organizational jurisdiction of MCBCL. These management tools, commonly employed by NCCOS, were critical for bridging the gap that often occurs between scientists and managers.
The key elements and recommendations of DCERP, its contributions to coastal EBM, and its relevance for employing EBM at other coastal military installations were published in the Journal of Environmental Management.