Coastal marsh modeling to help endangered species managment

By on July 23, 2012

“Collecting data in marshes and mudflats is an inherently messy business,” says Kevin Buffington, Biological Science Technician with the U.S. Geological Survey’s Western Ecological Research Center in Vallejo, Calif. Buffington knows well the messy business of studying coastal marsh because, since August, 2010, he has spent long workdays walking transects in the San Francisco Bay marsh, collecting data. The data gathered from this dirty work will impact the future of endangered species in tidal marshes from San Diego to Seattle.

Kevin Buffington is the lead field coordinator in charge of logistics for the Coastal Ecosystem Response to Climate Change (CERCC) program. CERCC is a USGS program that is developing site-specific response models to help land managers and others understand the implications of sea-level rise on endangered species. The project began as the subject of dissertation research by Karen Thorne, a biologist at the Western Ecological Research Center, at San Pablo Bay National Wildlife Refuge, a tidal estuary that forms the northern extension of San Francisco Bay.

A grant allowed the project to spread to 12 marshes around San Francisco Bay. In May, 2012, the program received two USGS Climate Science Center grants to expand the modeling work to 15 marshes from Puget Sound to San Diego to assess differences in coastal marsh vulnerability to sea level rise. The process of collecting data at the new sites will commence this fall.

The unique data and models will benefit decision makers at marshes along the West Coast. “Local land managers are in need of on-the-ground data that characterizes their current resources and response models that are at a scale that is useful to make long-term decisions,” Buffington said. “While global climate models can be downscaled to 1×1 km pixels, our models are developed at 5 x 5 m resolution, making them more valuable for the decision-making process.”

USGS coastal marsh data collectionIn the San Francisco Bay marshes, field data was used to create models of the continuous elevation of the marshes. Combined with data about the sediment dynamics and vegetation, Buffington and crew members projected what future habitats will look like for wildlife, particularly endangered species like the salt marsh harvest mouse, the California clapper rail and the state-threatened California black rail.

In teams of two, the crew involved in the project methodically mapped out characteristics of the marshes. Walking transects that were spaced 50-meters apart, one member operated a real time kinematic GPS, taking elevation measurements every 12.5 meters, while the other conducted vegetation surveys every 50 meters. Water data was collected periodically, as well, using a Solinst Levelogger Jr.

With current sea level rise rates at 3.1mm per year, a rate that is projected to increase exponentially at the end of the century, the data collected will aid in future decisions. “Marshes in San Francisco Bay are heavily fragmented and impacted by urbanization and are thus in relative high risk in terms of sea-level rise.” Buffington said. “Without an understanding of how sea level rise or climate change is going to affect marshes, the endangered species that require these areas for survival would be at even greater risk for extinction or extirpation.”

Buffington is hopeful that the research will yield valuable data to be drawn upon for years to come. “We hope that by providing managers with site-specific response models, the decisions they make will sustain tidal marsh habitats,” he said. “Our models may have implications for deciding where to begin restoration projects and which areas may require drastic management actions to preserve existing habitat.”

Photos courtesy of Kevin Buffington

Leave a Reply

Your email address will not be published. Required fields are marked *