As coastal ecosystems feel the heat of climate change worldwide, new research shows the humble mussel and marsh grass form an intimate interaction known as mutualism that benefits both partner species and may be critical to helping these ecosystems bounce back from extreme climatic events such as drought.
The study, led by the University of Florida, finds that when mussels pile up in mounds around the grass stems, they provide protection by improving water storage around the grass roots and reducing soil salinity.
Mussels protect grasses from drought by improving water storage around the grass roots and reducing soil salinity.
With mussels’ help, the study found, marshes can recover from drought in less than a decade.
"It’s a story of mutual benefit between marsh grass and mussels," said Christine Angelini, an assistant professor of environmental engineering sciences in UF’s Herbert Wertheim College of Engineering and lead author on the paper.
They found that wherever there were clusters of mussels embedded in the mud around the base of the grass stems, the grass survived; in fact, grass growing in mussel clusters had a 64 percent probability of surviving versus a 1 percent probability in areas where there were no mussels.
One of the research team’s marsh study sites was in the backyard of Dale Aren of Charleston, South Carolina.
After noticing the marsh behind her home was dying, she did some online research and found a paper about that very problem written by Angelini’s colleague, Brian Silliman, an assistant professor of biology at UF and a co-author on Angelini’s paper.
"We were worried," Aren said.
"The Spartina [grass] is beautiful and the increasing area of mudflats were very unattractive and did not look healthy."