Extensive Sand Dune Loss Threatens California Coast (eos.org)

A new study reveals that California has lost 60% of its coastal sand dunes since the mid-1800s, a significant decline that poses risks to both biodiversity and coastal protection. These dunes, which support various plant and animal species, including federally protected birds like least terns and western snowy plovers, are increasingly threatened by human development, sea level rise, and invasive species. The research team, led by Baxter et al., utilized a combination of historical maps, aerial photography, and lidar data analyzed with machine learning techniques to document the extent and distribution of these ecosystems over time. The findings indicate that California has lost approximately 442 square kilometers of sand dunes, significantly reducing their connectivity and habitat quality. While some areas have seen slight expansions due to new sand accumulation, these gains are insufficient to offset the dramatic losses. With climate change intensifying winter storms, the absence of robust dune ecosystems could heighten the risk of flooding for coastal communities reliant on dunes for protection. This study underscores the urgent need for conservation strategies to safeguard these vital ecosystems from further decline.