Getting the Dirt on Sand
A New Plan for Enhancing Shoreline Resilience in a Changing Ecosystem
By Max Delaney and Wendy Kordesch
It’s a sunny September afternoon in Stinson Beach, California—the perfect beach day. Among the sunbathers and joggers, geological oceanographer Dr. Wendy Kordesch from NOAA’s Greater Farallones National Marine Sanctuary is digging in the sand, as if an X marks the spot. She’s hunting for treasure, but it’s not gold. Tiny particles of sediment like sand, silt, and clay are invaluable in uncovering clues about the history of the coast and how it functions. However, despite picturesque settings on a sunny day, change is on the way for our coastal ecosystems.
Today, according to the California Resources Agency, almost 80 percent of the state’s coastline is actively eroding, threatening wildlife, reducing recreation opportunities, and damaging infrastructure. Decades of development, like building seawalls, breakwaters, and upstream dams, have reduced or otherwise altered the natural flow of sediment to beaches and coastal wetlands. Today, more than 10 percent of California’s coastline is covered in artificial structures. These artificial structures often cause further erosion, disrupt normal seasonal erosion and deposition patterns, and fix the shoreline in place so coastal ecosystems are unable to expand inland naturally as sea level rises. As the effects of climate change and sea level rise become more dramatic, bigger waves and more intense storms will increase and accelerate the erosion of sediment from beaches and further narrow shorelines along the north-central California coast.
Building a Regional Approach: It’s a Shore Thing
To address the challenges facing the north-central coast, Greater Farallones National Marine Sanctuary is increasing its efforts to understand how the coast and its habitats are changing, and how to adapt to future conditions. In November 2019, the sanctuary released its new Coastal Resilience Sediment Plan. The plan is a first-of-its-kind document that attempts to align planning efforts, coastal managers, and guidance documents across the region to achieve collaborative, holistic, and nature-based solutions to increase shoreline resilience.
The plan provides a 50-year road map to help shorelines on the north-central California coast adapt to hazards such as severe storm surge, sea level rise, erosion, flooding, and human impacts. It identifies 29 locations where forming and strengthening partnerships while prioritizing research, monitoring, and education, along with the use of nature-based techniques, can restore and protect coastal habitats while increasing coastal resilience. To help carry out the plan, the sanctuary founded a first-of-its-kind North-central California Coastal Sediment Coordination Committee, a group of 14 federal, state, and local agencies committed to collaborating on coastal resilience initiatives across the region.
Together, these new tools will help to anticipate areas of concern, focus resources and restoration projects, and ultimately build stronger and more resilient coastal communities.
Back on the beach, Kordesch stalks the shoreline of Bolinas Lagoon in search of more sedimentary clues, such as loose sand slipping from a steep bank signaling erosion, or a broad vegetated bank indicating a stable shoreline. These clues will further inform a restoration project in Bolinas Lagoon, one of the sanctuary’s first projects that will benefit from the new plan. The project demonstrates the use of a new and innovative nature-based shoreline protection technique: creating a naturally resilient “living shoreline.”
The project aims to use natural materials and native vegetation, or a “living shoreline,” to stabilize the coast and reduce erosion while also creating habitat and improving the lagoon’s overall health and function. Unlike a concrete seawall or other hard structure that impedes the growth of plants and animals, living shorelines grow over time and adapt as sea levels rise.
Projects like these exemplify a new approach to managing the coast and its future, one that works holistically and collaboratively to promote climate-smart solutions to coastal impacts so we can continue to enjoy lazy sunny afternoons on the beach for a long time to come.
Max Delaney is the permit coordinator at Greater Farallones National Marine Sanctuary. Wendy Kordesch is the geological oceanographer at Greater Farallones National Marine Sanctuary.
For more information, email Wendy Kordesch, Ph.D., at email@example.com.
California Resources Agency (CRA). 2017. “Safeguarding California: 2017 Update” Draft Report. California’s Climate Adaptation Strategy. Sacramento, CA.
Griggs, G.B., 2010. The effects of armoring shorelines—The California experience, in Shipman, H., Dethier, M.N., Gelfenbaum, G., Fresh, K.L., and Dinicola, R.S., eds., 2010, Puget Sound Shorelines and the Impacts of Armoring— Proceedings of a State of the Science Workshop, May 2009: U.S. Geological Survey Scientific Investigations Report 2010-5254, p. 77-84.