Guidance relevant to the maintenance and restoration of coastal salt marshes in the face of sea level rise is limited and sometimes conflicting; an understanding of ecological considerations and best management practices are needed to inform restoration and management that is appropriate, timely, successful, and sustainable. A literature search was conducted to assess the severity of current and projected impacts of sea level rise on salt marshes throughout the coastal regions of the United States, to identify other stressors contributing to relative sea level rise, to assess and consolidate current practices in marsh management, and to identify knowledge gaps that are impediments to development of consistent best management practices for restoring or maintaining marshes exhibiting degradation due to relative sea level rise. Literature identified in this search is synthesized, organized by stressor type, relevant metrics, management actions, and adaptive management. The citations are presented in such a way as to be easily utilized by managers of marshes degraded by relative sea level rise. The results of this literature search will inform data acquisition efforts to address data gaps and uncertainties necessary to support development of a holistic approach to identifying, sustaining, and restoring impacted marsh areas. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.
Coastal vegetation, including marsh and submerged aquatic vegetation (SAV), is threatened in many places across the United States and globally. Human activity, sediment starvation, and subsidence, among other factors, put these ecosystems at risk (Kirwan and Megonigal 2013; Orth et al. 2006). One type of SAV, seagrass, is of particular ecological importance, providing food and critical habitat for numerous coastal species. However, seagrass is currently in decline globally due to the aforementioned factors (Eleuterius 1987). Identifying the necessary conditions to promote seagrass recovery and growth is highlighted as one of the "important yet essentially unanswered questions" globally in the U.S. Geological Survey's (USGS) report on seagrass coverage in the Mississippi Sound from 1940-2002 (Moncreiff 2007). In sandy barrier island systems, where seagrass habitat has been related to barrier island stability and length, there is a distinct need to quantify in detail the conditions that will promote seagrass recovery and growth (Carter et al. 2011; Eleuterius 1987; Pham et al. 2014). This report introduces a new methodology for quantifying the relationship between seagrass habitat and its physical environment, including substrate and geomorphological characteristics. BACKGROUND: Studies relating seagrass growth to physical conditions tend to focus on finegrained estuarine environments, where wave exposure and light are identified as primary limiting factors for growth (Boer 2007; Koch 2001; Livingston et al. 1998). Important seagrass ecosystems also occur in sandy, geomorphologically dynamic barrier island systems, where controlling factors such as wave energy and rapid deposition or erosion can be much more complex (Pham et al. 2014). Seagrass Ecosystems. Barrier island systems are ecologically unique. They form the boundary between high-energy marine environments and low-energy back-barrier marshes, bays, or sounds. Barrier islands are composed of unconsolidated sediments, and are therefore dynamic. Storms, sea-level rise, and sediment supply are the primary controlling factors of their formation,
The U.S. Army Engineer Research and Development Center (ERDC) solves the nation's toughest engineering and environmental challenges. ERDC develops innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the Department of Defense, civilian agencies, and our nation's public good. Find out more at www.erdc.usace.army.mil. To search for other technical reports published by ERDC, visit the ERDC online library at https://erdc-library.erdc.dren.mil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.