A new study reveals how climate change has enabled a voracious crab species to dramatically alter salt marsh ecosystems across the southeastern U.S.
A new study reveals how climate change has enabled a voracious crab species to dramatically alter salt marsh ecosystems across the southeastern U.S.
The study, published in Proceedings of the National Academy of Sciences, shows that soils beneath salt marshes from South Carolina to Florida have been softened by higher sea levels and increased tidal inundation. That softening has allowed the burrowing crab species Sesarma reticulatum to thrive, feeding on the cordgrass that holds the marshes together.
The clearing of grass by crabs has dramatically altered the flow of creeks that run through the marshes, the study found, and is altering the dynamics between predator and prey species in the marshes. In fact, the researchers say that Sesarma, which had previously been a minor player in southeastern salt marshes, can now be considered a keystone species, meaning it plays a dominant role in shaping the ecosystem.
“What we’ve found is an example of how sea level rise can activate a keystone species that’s now dramatically remodeling these salt marshes,” said Mark Bertness, a professor emeritus of ecology and evolutionary biology at Brown University and a coauthor of the research. “That’s a big deal because sea level rise is a pervasive global phenomenon, and this is a largely unexpected consequence. We need to start thinking about how global climate change could activate new keystone species in other ecosystems.”
Read more at Brown University
Image: Burrowing crabs reshaping salt marshes, with climate change to blame (Credit: Christine Angelini)
