Sonoma, Calif. (Oct. 5, 2020) – The second phase of an ambitious project to revive 400 acres of tidal marshland to become vital habitat for everything from wading birds to small mammals to spawning steelhead, broke ground today just north of San Pablo Bay. Sonoma Creek extends nearly 35 miles from northeast of the town of Kenwood to where it empties into the bay. Sonoma Creek Marsh, the site of the current project, is referred to as a “Centennial Marsh” because of the manner in which the marsh formed. Sediment flowing into the Bay from hydraulic mining practices during the Gold Rush, caused a swift buildup of sediment against bayside levees. Sediment built up too quickly for natural channels to form and provide daily tidal flushing. King tides and storm events bring water onto the marsh plain, which cannot drain and creates stagnant ponds within the marsh. The project is a joint effort by Audubon California, San Pablo Bay National Wildlife Refuge, and the Marin-Sonoma Mosquito and Vector Control District to alleviate ponding, and improve function of the tidal marsh habitat.
“Our hope is that this project serves as an example of not just how to restore important coastal marshes across the country, but of how to make them an effective buffer to rising seas caused by climate change,” said Andrea Jones, director of bird conservation for Audubon California. “By creating tidal channels that would have existed in a naturally created marsh, we’re enhancing one of the most important bird areas on the West Coast, as well as eliminating stagnant pools where mosquitos breed. This is a win-win for birds and people.”
“Restoring the Sonoma Creek marsh will help communities in the northern Bay Area learn how to adapt to a changing climate,” said Karen Hyun, vice president for coastal conservation at the National Audubon Society. “A healthy marsh can reduce flooding from storms and rising seas, acting as a first line of defense against climate change for both birds and people.”
The Sonoma Creek enhancement is the first project of its kind due to the incorporation of sea level rise adaptation elements on an existing marsh, and serves as a national example of how to restore habitat and build climate resiliency. Before the first phase of the project, completed in 2015, seawater was able to wash in during high tide, but with no way for it to drain, stagnant pools became a perfect breeding ground for mosquitoes and an imperfect breeding ground for plant life and other animals. The single channel dug then, almost a mile long, allows some of those pools to replenish and drain, reducing the threat of mosquito-borne diseases to nearby residents. Dredged material was used to create a gently sloping transition zone, providing protection against climate-driven, storm surge flooding for local properties and a high-tide refuge for wildlife. Phase II of the project will dig and widen additional channels and use the dredged material to create islands throughout the marsh to serve as important resting habitat for shorebirds, particularly during hightide events and storm surges.
“High tide refugia created by this project is crucial to the survival of endangered species and other marsh dwelling wildlife during storm events, the intensity and frequency of which are predicted to increase with climate change” said Meg Marriott, Wildlife Biologist for San Pablo Bay National Wildlife Refuge.
The San Pablo Bay National Wildlife Refuge is a designated Important Bird Area by the National Audubon Society and is home to endangered Ridgeway’s and Black Rails, the federally endangered Salt Marsh Harvest Mouse, and many other types of wildlife. Completion of the project is expected in November.
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Media Contact: Jason Howe, 415-595-9245; jason.howe@audubon.org
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The National Audubon Society protects birds and the places they need, today and tomorrow. Audubon works throughout the Americas using science, advocacy, education, and on-the-ground conservation. State programs, nature centers, chapters, and partners give Audubon an unparalleled wingspan that reaches millions of people each year to inform, inspire, and unite diverse communities in conservation action. A nonprofit conservation organization since 1905, Audubon believes in a world in which people and wildlife thrive. Learn more at www.audubon.org and on Facebook, Twitter and Instagram @audubonsociety.