Conserving California’s Coastal Habitats
Sea level rise poses a new, serious threat to coastal habitats already impacted by human activities and populations focused along the coast. To inform current and future adaptation decisions and conservation actions, The Nature Conservancy in California and the California State Coastal Conservancy (SCC) collaborated to produce the first statewide, comprehensive assessment of the vulnerability of California’s coastal habitats, imperiled species, and conservation lands to sea level rise.
We conducted this assessment in three steps:
- We characterized the current state of the entire California coast, including San Francisco Bay, in terms of 40 wetland and terrestrial habitats, 159 imperiled species, 17 built environment classes, conservation management status, and a biodiversity index.
- We developed a spatially explicit vulnerability index to map and quantify the vulnerability of all 40 habitats, impacts to conservation lands, and potential impacts to imperiled species.
- We combined vulnerability results with conservation management status and other data to develop a wall-to-wall conservation blueprint comprised of five strategies to maintain coastal habitat area in the face of sea level rise and other stressors.
The vulnerability results are grim: 55% of current habitat by area is highly vulnerable to five feet of sea level rise. That includes 60% of California’s iconic beaches, 58% of rocky intertidal habitat, 58% of marshes, and 55% of tidal flats. In addition, sea level rise will further stress populations of 39 rare, threatened, or endangered species, and 41,000 acres of public conservation lands are projected to be drowned by subtidal waters.
The conservation blueprint, however, is a picture of hope. The Assessment represents the basis for the proposition that we can have as much or more coastal habitat statewide with five feet of sea level rise as we do today, but it will require concerted effort.
Both TNC and SCC are using this study as the science foundation for action – to guide and drive our own conservation and adaptation actions throughout the coast. We call on other decision makers and coastal property owners to put this Assessment to work – it is only through vigorous, coordinated action that we can maintain the area of coastal habitats in the face of sea level rise and other stressors, and ensure that future generations enjoy the same character and benefits of our coast that we do today.