NCCOS-funded researchers published a study in which a panel of coastal experts evaluated the effectiveness of proposed management actions in Mississippi/Alabama (MS/AL) for reducing future coastal hazards. Drawing on leading science in the region, the panel found that adding sand to beaches and dunes may reduce long-term barrier island erosion and storm damage. The experts also suggested that marshes could shrink under future sea level rise if left unmanaged, potentially increasing flooding in nearby communities. Regardless of restoration actions, the panel agreed that flooding during extreme storm events is likely to increase across the region as sea levels rise.
For the study, the research team assembled a panel of eleven United States Geological Survey (USGS) coastal scientists with expertise spanning engineering, ecology, biology, oceanography and geology, all of whom had worked across multiple locations in the southeastern United States.
The panel evaluated three proposed restoration scenarios: (1) restoring the interior headlands in Grand Bay, MS/AL, to the historic 1848 footprint; (2) renourishing beaches and dunes at Dauphin Island, AL, including extending the shoreline to the historic 1957 position; and (3) taking no management action. Panelists were then asked to estimate how each scenario, combined with different rates of sea level rise, could affect the barrier islands, estuaries, and marshes by 2050. Performance metrics included hurricane storm surge flooding, salt marsh acreage, and barrier island characteristics such as dune height and island width.
Collectively, the experts agreed that storm surge flooding is likely to increase by 2050 due to sea level rise, regardless of management actions. While marsh responses showed greater uncertainty—particularly under lower rates of sea level rise— the panel agreed that marsh extent would decline if no action was taken, especially in areas already experiencing erosion. The experts were in agreement that beach and dune nourishment may help reduce long-term barrier island erosion, noting that the size and location of management actions influence coastal response. Across all scenarios, the panel of experts emphasized the dynamic nature of coastal systems and the interactions among biological, geological, and physical processes that shape coastal landscapes.
Coastal managers often rely on observations and predictive models to guide decisions aimed at improving coastal resilience. When data or models are limited, developing them can require substantial time, funding, and technical expertise. In many instances, natural resource managers are not able to postpone management decisions until monitoring data or well-developed models are available. The research team concluded that structured expert input can be a valuable tool for providing timely insights, prioritizing future research, and informing decisions about where to focus research, monitoring, and management efforts.
The project is led by the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center and includes co-investigators from the U.S. Geological Survey Eastern Ecological Science Center, U.S. Geological Survey Wetland and Aquatic Research Center, and the University of Georgia School of Environmental, Civil, Agricultural and Mechanical Engineering. The project is funded through the NCCOS Effects of Sea Level Rise Program.
This work is authorized by the NOAA Authorization Act of 1992, Pub. L. 102-567 (Oct. 29, 1992); sec. 201(c), which directs appropriation for the NCCOS Competitive Research Program to augment and integrate existing NOAA programs, with a specific focus on improving predictions of coastal hazards and protecting human life and property.
Citation: Passeri, D. L., Richardson, M., Martin, J., Yurek, S., Alizad, K., Bilskie, M. V., Flocks, J., Frank-Gilchrist, D., Jenkins, R. L., Mickey, R. C., Palmsten, M. L., Smith, C. G., Smith, K. E., & Zeigler, S. L. (2025). An expert elicitation to inform coastal management decision-making for mitigating future hazards. Journal of Environmental Management, 394, 127447. https://doi.org/10.1016/j.jenvman.2025.127447