Sonoma Creek Marsh’s New Look is a Boon for Wildlife

Trudging along a channel in Northern California’s Sonoma Creek Marsh one day in January, Courtney Gutman stopped suddenly and dropped to her knees in the mud. “Amazing!” shouted Gutman, the restoration project manager for Richardson Bay Audubon. “Look how quickly it grew back!” The source of her amazement was a one-inch-tall, magenta-stemmed heath sprout poking out of a patch of soil.

A single sprout in a sea of mud might not seem like cause for celebration. But the appearance of a native plant in the formerly barren Sonoma Creek Marsh signaled a wetland slowly returning to health, thanks to a project led by Audubon California, the U.S. Fish and Wildlife Service, and the Marin-Sonoma Mosquito and Vector Control District. The project was to create 400 acres of much-needed habitat for wildlife like the endangered Ridgway’s Rail and the California Black Rail.

Wetlands are scarce here in San Pablo Bay, where 90 percent of tidal marshes have been lost to agriculture. Sonoma Creek Marsh had potential, but it also had problems—the marsh started forming during the 19th century, when mining sediment washed into the bay. But the marsh formed so quickly that the network of channels healthy tidal marshes need to circulate seawater didn’t have time to develop. Instead, water brought in by the tide had no way of draining out, killing plant life and making the marsh uninhabitable for rails and other species.

The marsh was, on the other hand, extremely hospitable to mosquitoes—the MSMVCD was ultimately spending more than $60,000 a year on insecticides. So in 2010 the agency enlisted Audubon California and the USFWS to help nurse the marsh back to health. Last fall the three organizations completed the $3 million project by carving out seven acres of new channels that allow seawater to flow in and out of the marshland. The excavated soil was used to build mounds and a ramp to the levee that separates the marsh from farmland, creating a high-tide retreat for birds and mammals that will become only more crucial as climate change causes sea levels to rise and storm surges to increase.

Monitoring has just begun at the site, but when a tide flooded the marsh just weeks after construction ended, hundreds of shorebirds perched on the ramp and soil mounds to wait out the high waters. “It provided refuge for them,” Gutman said. “That’s what we want to see.”