A regional multidisciplinary approach to assess climate change impacts to Pacific coast wetlands for informing adaptation strategies

Climate change effects on coastal ecosystems will include rising sea levels and changes in the frequency and duration of storms.  Sea levels are projected to increase up to 143 cm by 2100 along the Pacific coast and storms are expected to increase in frequency and magnitude, both threatening the persistence of ecosystems at the land-sea interface including estuaries, mud flats, and tidal marshes.  Land managers are tasked with conserving these coastal ecosystems and the species dependent upon them.  However, climate adaptation plans are challenging for managers to develop, primarily because detailed baseline data of current conditions, relationships among linked habitats, and models that project future conditions at a local scale are often lacking.  To provide science support for climate adaptation planning, the USGS has developed a multidisciplinary Pacific coastal program (CERCC) to monitor and model sea-level rise and storm impacts to nearshore ecosystems.  Working with Oregon State University and the University of California at Los Angeles and Davis, CERCC provides data sets and modeling to assess climate change impacts along a latitudinal gradient in 18 estuaries in California, Oregon and Washington by collecting elevation, vegetation, water level, salinity, and accretion data.   We used radioisotope dating from sediment cores to calibrate a Wetland Accretion Response Model for Ecosystem Resilience (WARMER) that projects marsh elevations under sea-level rise scenarios through 2100.  We found sea-level rise resilience varied across the Pacific coast and are driven by local processes, climate and the extent of modification of the estuary.