New Study Offers Hope for Coastal Regions Even as Climate Change Intensifies Storm Risk

The finding, co-headed by a Johns Hopkins University geochemist and reported recently in the Science Advances journal, provides rare optimism for the fate of one of Earth’s most crucial ecosystems as climate change changes the global pattern of intense storms.

The research team, co-headed by the California Institute of Technology and the University of Colorado, Boulder, had been learning about Little Ambergris Cay, an unoccupied island in Turks and Caicos, in particular, the island’s microbial mats.

Microbial mats are a spongey ecosystems that for eons have sustained a diverse array of life from the microscopic organisms that that make a home in the upper oxygenated layers to the mangroves it helps root and stabilize, which in turn provide habitats for even more species.

Globally, mats can be discovered in wildly diverse surroundings, but the variety this group studied is generally discovered in tropical, saltwater-oriented places. These are exactly the coastal locations that are highly vulnerable to severe storms.

In September 2017, the eyewall of Category 5 Hurricane Irma directly hit the island that the team had been working on.

The tropical cyclone’s effect was instantly devastating, thereby choking the mats with a blanket of sandy sediment that destroyed new growth. But as the group checked on the site initially in March 2018, then again in July 2018 and June 2019, the researchers were excited to observe the mats regrowing. The new mats started to visibly sprout in just 10 months.

New mat growth advanced quickly and indicated that storm perturbation might streamline these ecosystems that have been adjusting to altering sea levels.

The research team included co-senior author Woodward W. Fischer., Nathaniel T. Stein, Kyle S. Metcalfe, Theodore M. Present, Victoria J. Orphan, and John P. Grotzinger, all of California Institute of Technology’s Division of Geological and Planetary Sciences; Andrew H. Knoll of Harvard University; and co-senior author Elizabeth J. Trower of the University of Colorado Boulder.

This study was financially supported by the Agouron Institute, NASA Research Opportunities in Space and Earth Science grant 80NSSC18K0278, and the NSF GRFP.