Importance of Coastal Wetlands Highlighted

Changes in rainfall and temperature are predicted to transform wetlands in the Gulf of Mexico and around the world within the century, a new study from the USGS and the University of Texas Rio Grande Valley concludes.

Such changes are expected to affect the plant communities found in coastal wetlands. For example, some salt marshes are predicted to become mangrove forests, while others could become salty mud flats.

These shifts in vegetation could affect the ecological and economic services wetlands provide to the communities that rely on them.

“Coastal wetlands are an invaluable resource,” said Christopher Gabler, a former USGS scientist, currently an assistant professor at the Texas university, and lead author of the study.

“They protect surrounding communities from storms and coastal erosion, support fisheries and wildlife, purify water pollution, and help prevent dead zones from forming in the Gulf.”

It’s unknown exactly how these services would be affected as wetlands transform in response to climate change, which has many different facets. Though studies on climate change impacts in wetlands have typically addressed sea-level rise, this research looked at aspects of climate change that have received little attention.

“Most studies have focused on the impact of sea-level rise on coastal wetlands and have excluded the important role of temperature and precipitation,” said Michael Osland, a USGS research ecologist and study co-author.

“We know that climate influences how these wetlands look and work, so this study aimed to demonstrate the importance of considering these forces when modeling what coastal wetlands may look like in the future.”

The intensive study relied on field studies at 10 estuaries in five states (Texas, Louisiana, Mississippi, Alabama and Florida) along the northern Gulf of Mexico.

The fieldwork took place in a variety of coastal wetland types, including mangroves, marshes and salt flats.

The project was supported by the USGS’s Ecosystems Mission Area and its Climate & Land Use Change Program and the South Central Climate Science Center.