Pictured above: Coastal sand dunes rise above the ocean. Image via The Current.
A UC Santa Barbara-led assessment found major losses in California’s coastal dune systems, with implications for habitat, coastal protection and sea level rise planning.
A UC Santa Barbara-led assessment has found that California has lost 60% of the coastal dune systems that existed in 1850, a major decline with implications for habitat protection, coastal resilience and planning for sea level rise.
The study, the first comprehensive assessment of its kind for the California coast, estimates that dune systems declined from about 739 square kilometers in 1850 to almost 300 square kilometers after 165 years. The losses were driven largely by urban development, land-use changes and erosion.
The research was led by Tim Baxter, a postdoctoral researcher and physical geographer who conducted the work as a member of geography professor Ian Walker’s SANDLab. The team also included researchers from UC Santa Barbara’s Marine Science Institute and other collaborators.
“There are major implications of this loss for the California coast, including reduced habitats for plants, insects and other invertebrates, birds and small mammals,” Baxter told The Current. “Importantly, we also lose coastal protections against storms and sea level rise.”
The researchers used historical archive analysis, machine learning tools, site visits, historical maps, high-resolution aerial photographs and lidar to map how coastal dune systems have changed over time.
The work provides a framework that could help identify and prioritize potential restoration sites along coasts facing sea level rise and other climate-related pressures.