‘FAMINE TO FEAST’
Storms get salmon spawning season off to robust start
Marin biologists say the early storms have resulted in a strong start to the yearly salmon spawning season, including unprecedented fish sightings in some creeks.
Streams and creeks that were bone dry after two years of drought were suddenly flush for spawners safter a historic storm in late October that dumped 26 inches of rain on Mount Tamalpais, plus a weaker storm about a week later.
“It’s been so crazy that we went from famine to feast when it comes to the salmon,” said National Park Service biologist Michael Reichmuth.
On Redwood Creek, where conservationists have been working to revive struggling salmon runs, researchers such as Reichmuth documented the first sightings of adult Chinook salmon in the creek since monitoring began 20 years ago. Where researchers would be lucky to find a couple of dozen coho salmon spawners in the creek during the past two winters, Reichmuth and his team found nearly 70 Chinook salmon in a single day.
“It’s a big change considering that a month earlier we were rescuing juvenile salmon and moving them from pools that were drying up,” Reichmuth said.
Several other creeks had first-time sightings of Chinook salmon spawners, including Olema Creek, Woodacre Creek and Pine Gulch Creek. Central coast Chinook salmon are listed as a threatened species under the federal Endangered Species Act.
“It’s encouraging to see the fish persisting, and so far the flows have helped get fish up,” said Preston Brown, conservation director with the Olema-based Salmon Protection and Watershed
“Very few things are as exciting to a fisheries biologist as an unprecedented diversity of fish.”
— Eric Ettlinger, Marin Municipal Water District
Network. “I’m just excited that we can celebrate the successes when we have them. Let’s hope this year is a success.”
On the county’s main salmon stronghold at Lagunitas Creek, Marin Municipal Water District biolo
gist Eric Ettlinger found four species of salmon in a single day, including coho, Chinook and the rarer pink and chum species. Ettlinger said this was a first.
“Very few things are as exciting to a fisheries biologist as an unprecedented diversity of fish,” Ettlinger said.
This unusual gathering did lead to some odd interactions, Ettlinger noted, including a “very confused male pink salmon attempting to spawn with a female coho.”
“The female appeared to have spawned already, and in any case, these species can’t interbreed,” Ettlinger said.
The recent downpours provided other benefits to local creeks and streams. The swift flows washed away algae that built up over two years of drought. Several large willows were toppled into the creeks, which will help to provide a variety of benefits to both young and older fish, including habitat, food sources and shelter from predators.
“It really rejuvenated Lagunitas Creek in many ways and made some terrific habitat for young fish and also for the adults coming up,” Ettlinger said.
The storms can have the opposite effect as well, Reichmuth said. While strong flows can help scour the creek bed and create deep pools that are vital to both spawning and young salmon, they also can blow out existing pools as well.
“So far it looks like there is more of a gain than a loss,” Reichmuth said.
Now researchers are awaiting the return of the county’s endangered coho salmon spawners. While some coho salmon have been found in local creeks so far, most spawners arrive in December.
Lagunitas Creek, which runs from its headwaters on Mount Tamalpais and flows into Tomales Bay, hosts the largest remaining population of coho salmon from the northern end of Monterey Bay to Mendocino County. Listed as a federally endangered species, coho salmon have dwindled primarily from habitat loss caused by land-use changes and development that caused creeks to fill in with sediment and tributaries to be blocked by dams.
A federal recovery target seeks to restore the run size to more than 1,600 salmon egg nests, or redds, for three consecutive years. But in more than 25 years of monitoring, the counts have never reached half that amount.
While this salmon season has had an encouraging start, more rain will be needed when coho arrive to allow them to push upstream toward their spawning grounds. And there’s no guarantee Marin will see another large storm this winter.
“We have seen before where you get these early storms and the tap turns off,” Reichmuth said.
The drought will also have an impact on Lagunitas Creek spawners this year. The Marin Municipal Water District, which dammed Lagunitas Creek to create the reservoir system serving twothirds of county residents, is releasing less water into the creek for fish in order to preserve its reservoir supplies.
This emergency authority granted by the state requires the district to significantly increase its creek monitoring. While the district is allowed to reduce dam releases, it is not allowed to harm endangered or threatened salmon. Should fish passage become restricted or salmon eggs come close to being exposed to the air, the district will be required to release more water.
Coho salmon have a threeyear life cycle. After hatching, the young salmon rear in freshwater for about a year and a half to fatten up and grow before swimming out to the ocean as smolts. After about another year and a half, the salmon return to the same creek they were born in to spawn and then die.
At Redwood Creek, young coho salmon face the new experience of sharing the water with the newcomer Chinook salmon babies, which are larger.
“There is only so much habitat for them and food. I wonder how is the competition going to play out later on,” Reichmuth said.