San Francisco Bay Salt Marshes Returning to Natural Conditions

July 7, 2021
Salt marsh in San Francisco bay.

Creative Commons (Kai Schreiber)

Salt marshes in San Francisco Bay are returning to more natural ecological conditions, after being impacted by changing sedimentation regimes and heavy metal pollution over the last ~150-200 years, according to recently published SW CASC-funded research. The researchers examined sedimentation rates and heavy metal accumulation data from three San Francisco Bay marshes to determine European impacts in the context of earlier variability. There was significant European impacts on the geochemistry of marshes over the past ~150-200 years, however, over the past few decades, conditions have been returning to those more typical of the immediate pre-European period. This suggests resilience in these ecosystems, but impacts from anticipated 21st century sea-level rise remain an important concern.