Wetland Evaluation and Sediment Elevation Monitoring and Analysis in the Indian River Lagoon

Science Center Objects

To better understand coastal response to sea-level rise, USGS is monitoring coastal wetland sediment elevations along Florida's east coast.

 

Map of Indian River Lagoon study sites

Map of Indian River Lagoon study sites

The Science Issue and Relevance: Coastal resource managers are challenged with understanding how coastal wetlands respond to sea-level rise and restoration practices. Changes in sediment elevation are an important metric of coastal wetland status. In a collaborative study, the U.S. Geological Survey (USGS), the St. Johns River Water Management District (SJRWMD), and SJRWMD partners are monitoring coastal wetland sediment elevations along the Indian River Lagoon (IRL) on Florida’s east coast to evaluate the long-term stability of these habitats and to improve the understanding of their responses to restoration. The Indian River Lagoon is an important estuary and wetland of coastal Florida, and monitoring is vital to preserve human habitation, wildlife, and long-term wetland viability. The study is important for assessing coastal response to sea-level rise, climatic change, and development of coastal communities, as well as biological responses to global change.

Methodology for Addressing the Issue: The Surface Elevation Table is a well-established method of measuring the relative elevation change of wetland sediments. The SET design allows for precise measurement of sediment elevation in wetlands to determine rates of elevation change, particularly relative to sea level rise, and to gain an understanding of the processes responsible for elevation change. The SET provides highly accurate measurements of sediment elevation over long periods of time relative to a fixed subsurface datum. In addition, surface marker horizons (powdered feldspar) will be used to assist in differentiating surface accretion/scouring from subsurface processes.

Researchers monitoring coastal wetland sediment elevations along the Indian River Lagoon

Researchers monitoring coastal wetland sediment elevations along the Indian River Lagoon

Researchers will collect new data from previously established Wetlands Initiative (WI) and Canaveral National Seashore (CNS) SET stations, and establish new stations near New Smyrna Beach for monitoring. Work in Year 1 will begin with a review of historical efforts and assisting with collection of data from existing SETs. In addition, new SET stations will be established, including stations on  Merritt Island National Wildlife Refuge (MINWR). After stabilization, initial readings will be completed at all new stations. After the fieldwork is completed, USGS will provide a summary of SET data that includes analysis of historical and new data and provide suggestions for auxiliary methods to supplement the SETs, such as feldspar markers.

Future Steps:  Examples of tasks to be considered in subsequent years include:

  • Assist with the collection of new SET data at WI stations and CNS stations
  • Assist with the collection of new SET data at the Mosquito Lagoon Marine Enhancement Center (MLMEC) and/or other identified stations
  • Analyze historical/new data and produce a SET data summary