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Decades of reduced water flow and the effects of climate change on sea level rise are causing rapid saltwater intrusion into the central Everglades. Scientists warn that one of the most alarming consequences of salt water intrusion is that sawgrass marshes, which are adapted to freshwater, are collapsing when exposed to salt.

The collapse of sawgrass marshes matters a lot – when it happens, the ground loses elevation, allowing salt water to more easily invade, worsening saltwater intrusion and creating a domino effect that perpetuates the issue and creates trouble for an already imperiled Everglades ecosystem.

In an effort to understand why and how marshes are collapsing, a team of researchers from Florida International University (FIU), the Everglades Foundation, Everglades National Park (ENP) and the South Florida Water Management District (SFWMD) are exposing freshwater and brackish sawgrass marshes to varying concentrations of salt and measuring the responses of plants, microbes, algae, and soils. What they have found so far is that even small increases in salt are causing freshwater-adapted plant roots to die. When roots die, the organic (peat) soils rapidly decompose, leading to marsh collapse and elevation loss.

This collaborative project aimed at understanding the causes and mechanisms of sawgrass marsh collapse was spearheaded by FIU scientists Drs. Tiffany Troxler, John Kominoski and Evelyn Gaiser, along with recent Ph.D. graduates Drs. Ben Wilson, Viviana Mazzei, Shelby Servais and Sean Charles, and done in collaboration with Dr. Stephen Davis from the Everglades Foundation as well as Dr. David Rudnick from the ENP and Drs. Fred Sklar, Chris Madden, and Carlos Coronado-Molina from the SFWMD.

Among the most important aspects of this study is that as a result of collaborations with the SFWMD and local partners, scientific findings are being directly translated into water management actions that can be taken to improve freshwater flows and slow down both saltwater intrusion and the process of marsh collapse.

*This research was conducted with support from the Florida Sea Grant and the Florida Coastal Everglades Long Term Ecological Research Program, part of the Long Term Ecological Research Network established by the National Science Foundation.

This work is the result of a powerful partnership between FIU and the Everglades Foundation. We pride ourselves on pooling our expertise and reach to train undergraduate and graduate students, conduct leading science to inform policy and management decisions, and engage and inform the public to protect and restore America’s Everglades.

Interested in supporting this work? Give today to ForEverglades Fellowship.