Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat

Science Center Objects

To ensure successful restoration of coastal wetlands, WARC researchers will measure carbon cycling processes that indicate ecosystem health and sustainability.

The Science Issue and Relevance: Coastal wetlands are some of the most productive and valuable habitats in the world. Louisiana contains 40% of the United States’ coastal wetlands, which provide critical habitat for waterfowl and fisheries, as well as many other benefits, such as storm surge protection for coastal communities. In terms of ecosystem services, biological resource production, and infrastructure investments, the value of Louisiana’s coastal wetlands exceeds $100 billion. Thus, stakeholders are gravely concerned about sea-level rise which is causing coastal marsh habitat to convert to open water and resulting in the highest rates of wetland loss in the world, with nearly 1.2 million acres lost since the 1930s. This concern has led stakeholders to invest millions in extensive restoration efforts of these valuable habitats, including those for commercial fisheries.

Louisiana salt marsh

Louisiana salt marsh located in proposed diversion impact zone. Pond in foreground illustrating marsh fragmentation. Eddy covariance tower in background collecting greenhouse gas emission data.

(Credit: Eric J. Ward, USGS. Public domain.)

Methodology for Addressing the Issue: Various hydrologic management methods have been used extensively in Louisiana’s coastal wetlands to maintain desirable habitat and sustainable ecosystems. Although historically less common, river diversions have the potential for large-scale impact and currently represent some of the largest climate adaptation management interventions ever implemented for coastal restoration. However, there remains a critical need for a greater understanding of the short- and long-term effects of river diversions on coastal wetlands. To ensure successful restoration of these vital habitats, it is necessary to understand the cause of wetland loss as well as accurately measure the effectiveness of restoration techniques.

The research team will measure carbon cycling processes that indicate ecosystem health and sustainability in coastal wetlands impacted by sea-level rise. This information will be used 1) to identify the processes that lead to wetland loss, and 2) as a baseline to assess the impacts and the effectiveness of the planned diversion of the Mississippi River. This information will help land managers to identify vulnerable habitat, assess restoration effectiveness, and optimize restoration outcomes.

Future Steps: Data collected from this research will be used to develop projection tools for land managers to predict impacts of land management and climate change on carbon sequestration and wetland resilience.