Given the public interest, and the continued restoration of the salmon habitat, the Marin Municipal Water District has introduced a new “spawner dashboard” that allows users to dive into the fishery’s data back to 1999.
“We were looking for a more engaging way to tell the story of salmon other than the kind of monitoring reports that we have been generating for years,” said Eric Ettlinger, aquatic ecologist for the district.
The Lagunitas Creek Spawner Dashboard, a resource of the Marin Municipal Water District, on a computer in Novato, Calif., on Wednesday, Nov. 5, 2025. (Alan Dep/Marin Independent Journal)
The online dashboard at bit.ly/3XgEYjG includes a map of the Lagunitas Creek watershed that displays where salmon and steelhead have laid their eggs, Ettlinger said.
The dashboard shows nesting grounds for coho, chinook, pink and chum salmon as well as steelhead trout. It also has charts that show the timing of the five largest coho salmon runs and the effect of stream flows on spawning.
The 2024-25 coho salmon run was the largest return to the Lagunitas Creek watershed in 30 years, with 674 coho redds, or nests, counted across all streams. Monitors observed a record 123 chinook salmon redds.
To be removed from federal endangered status, Lagunitas Creek coho must lay at least 1,600 nests for three consecutive winters. For the past quarter century, district counts have not reached 800.
Marin County has the largest population of wild endangered coho salmon from Monterey Bay to the Mendocino County-Sonoma County line. Once believed to have numbered in the thousands, coho populations dwindled to the hundreds during the 20th century because dam construction blocked miles of former spawning grounds and tributaries.
Coho salmon require deep, cool pools of water in gravelly creeks to spawn, and for the juvenile fish to grow during their 16-month stay in fresh water.
The Marin Municipal Water District has embarked on a multiyear, multimillion-dollar restoration project to reverse the adverse effects of dams by recreating habitat that used to occur naturally.
The restoration effort is a three-phase project designed to improve the stream from Peters Dam through Samuel P. Taylor State Park. In addition to boosting habitat for the endangered coho salmon, the project also supports habitat for freshwater shrimp and the threatened steelhead trout.
The project will add up to 4,450 linear feet of the channel, more than 270 logs and 12,000 tons of gravel to create the bed.
The second phase of the project required the closure of the Leo T. Cronin Fish Viewing Area parking lot. Work just wrapped up in time to reopen the lot so visitors can check out the salmon run.
Ettlinger said surveyors are starting to track the migration now. Already, staff have observed an adult chinook salmon and two pink salmon far upstream.
Small numbers of pink salmon were seen in Lagunitas Creek between 2017 and 2021, but they haven’t been detected again until this season, Ettlinger said. These fish may be offspring of undetected spawning in 2023, or strays from a population much farther north.
As for this year’s salmon run, it is expected to be smaller than last winter. It will be the offspring of about 200 coho that spawned in the watershed three years ago. The team expects the run to be around 400, smaller than average, but double the size of the parent generation, Ettlinger said.
Ettlinger said the effort to replenish salmon populations in the Lagunitas Creek watershed is just one piece of the puzzle. Other habitats throughout the state play a role as well.
Ettlinger said the Sonoma County Water Agency was an innovator in spawning data collection in the Russian River watershed and communication to the public. The Marin district has modeled much of what it does in Lagunitas Creek watershed after the work in Sonoma County, including the new dashboard, Ettlinger said.
Sonoma County Water Agency biologists were among the first to implement the use of passive integrated transponders, or PIT, which are tags that track juvenile fish, said Gregg Horton, an environmental specialist with the agency. The Marin Municipal Water District followed the lead and has used the technology for a number of years.
The Sonoma agency helped create the California monitoring plan for salmon and steelhead — now managed by the California Department of Fish and Wildlife — that tracks recovery and conservation efforts across the major state watersheds where the fish spawn.
The Sonoma agency also launched a comprehensive restoration effort in Dry Creek, a tributary to the Russian River.
“We are aware of the some of the challenges in Lagunitas and Olema; they are similar to what we face here,” Horton said. “We compare notes and try to keep abreast of what each other are doing.”
Aaron Johnson, an environmental specialist at the agency, said the Russian River had higher salmon returns last season than in the last decade thanks to restoration work.
Johnson said data reporting and collaboration helps inform agencies “in making decisions on where to focus restoration dollars and operations.”
© 2025 The Marin Independent Journal (Novato, Calif.). Distributed by Tribune Content Agency, LLC.
