Reviving 400-acres of wetland habitat in San Pablo Bay.
Audubon California staff at Sonoma Creek site. Photo: JoLynn Taylor
Audubon California is working with a number of partners to enhance 400 acres of tidal marsh habitat on the San Pablo Bay National Wildlife Refuge along Sonoma Creek. The project will benefit birds such as Ridgway’s Rails, Black Rails, and a number of marsh songbirds, along with the endangered salt marsh harvest mouse and native plants. Fish, such as coho salmon and steelhead, rely on healthy wetlands as habitat where juvenile fish can feed and grow.
The Sonoma Creek runs from Sonoma County into the San Pablo Bay on the northernmost end of the greater San Francisco Bay. More than a hundred years of mining and agricultural operations have greatly limited the ecological function of these wetlands. Open water sediment from hydraulic mining during the Gold Rush caused a rapid buildup of mud flats which were subsequently turned into farmland, and maintained by levees.
In the last three decades, tidal action has reclaimed some of the area, creating stagnant wetlands that built up too fast to form natural channels. These stagnant pools form algal mats and harbor mosquitos. The remaining agricultural land has now become too salty for most agriculture, and some has been sold or abandoned.
The core of the project will involve constructing a network of tidal channels within the marsh to drastically improve tidal exchange and nutrient cycling and provide habitat to a myriad of marsh-dependent wildlife species. The channels will also provide spawning and feeding grounds for endangered and commercial fishes. Improving hydrology will improve water quality by increasing circulation and drastically reducing the amount of pesticides applied to areas of ponded water that currently facilitate heavy mosquito production.
Implementation of the project will also provide hands-on educational opportunities for students who would not otherwise experience natural history in the field setting.
Audubon California is partnering on the project with the Marin-Sonoma Mosquito and Vector Control District and the San Pablo Bay National Wildlife. Consultants for this project are Wetlands and Water Resources, Inc. and ESA Associates. Construction is being carried out by Hanford ARC.
Designated as an Important Bird area, San Pablo Bay and its surrounding wetlands provide critical habitat for the birds of the Pacific Flyway. Birders visiting the refuge can see Brown Pelicans, White-tailed Kites, Golden Eagles, Peregrine Falcons, Common Yellowthroats, and migratory shorebirds including Whimbrels and Willets.
Funding and other support for this project has been provided by:
The above visual answers the question of why we are undertaking a large scale restoration project in San Francisco Bay. On the left is a healthy, functionining marsh in Baja California and on the right is the site of our restoration in Sonoma Creek Marsh, a dead marsh. The difference between a vibrant wetland system and dysfunctional one is dramatic.
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