Study: Without Action, SF Bay Tidal Marshes Will Disappear

November 16, 2011
An alarming 93 percent of San Francisco Bay’s tidal marsh could be lost in the next 50 to 100 years with 5.4 feet (1.65 meters) of sea-level rise and low sediment availability, according to a new study led by PRBO Conservation Science (PRBO). These figures represent the high-end sea-level rise scenario, which researchers say is increasingly likely.

The study, published this week in the journal PLoS ONE, assesses impacts of sea-level rise, suspended sediment availability, salinity and other factors on San Francisco Bay’s tidal marshes.

Tidal marshes are vital to migratory birds, commercial fisheries, other wildlife and people. Marshes act like giant sponges, protecting highways, businesses, homes and other structures by reducing flood impacts in large storm events and as sea levels rise. Tidal marshes also filter out pollutants and sequester carbon.

PRBO’s study indicates that not all marshes will be lost and that society’s actions today can keep more marshes intact as sea levels rise.

"Tidal marshes are incredibly resilient to changes in sea level, depending on how fast seas rise and how much sediment is available. Unfortunately, marshes cannot keep up with the high-end sea-level rise predictions on their own. They will need our help,” said Diana Stralberg, the study's lead author.

Lisa Schile and Maggi Kelly, of the University of California, Berkeley, were co-authors on the study.

Read the PRBO press release.

-Ann Brody Guy