The parade of storms dumping water on California has been a welcome sight to most everyone the Bay Area — at least almost everyone.
Swollen, rampaging creeks in West Marin have hampered the nesting of critically endangered coho salmon returning to their native streams to spawn. After years of devastating impacts by drought — it seems the spigot has turned the other direction.
“I guess I would say it’s almost too much of a good thing,” said Gregory Andrew, Fishery Program Manager for the Marin Municipal Water District.
The Lagunitas Creek Watershed represents one of the state’s most important spawning grounds for coho salmon. But the storm-fueled creeks are gushing at such a pace they’re blowing out the salmon nests, or reds, further placing their numbers in peril.
“Fish come in and lay their eggs in the gravel,” Andrew said, “and that gravel can be washed away by the high flows.”
Ecologists from the water district walk the creeks on weekly patrols counting the number of fish and nests in the creeks. But the early January storms made it impossible for the observers to see anything in the murky, fast-flowing water. Last week, Ettlinger waded through the San Geronimo Creek near Woodacre, looking for any signs of the gravel nests.
“If fish did spawn there’s no evidence of it,” said water district ecologist Eric Ettlinger during a recent observation outing, “so we seem to have missed a big chunk of the salmon run.”
Before the series of storms in early January, biologists with the Turtle Island Restoration Network counted about 360 returning coho salmon in the area. The number is steady compared to recent years — but far below the area’s once historic high of around 5000 fish. Turtle Island director Todd Steiner said the weather hasn’t created ideal nesting conditions in many years.
“Coming out of several years of drought — now we’re having several years of flood,” Steiner said. “Every one of those diminishes the numbers a little bit more and it pushes them to the edge where they can disappear forever from this eco-system.”
Steiner peered across the raging creek which backs up to his organization’s offices in Tocoloma. He said the creek is normally 15-foot wide creek but now spanned across 120 feet, swallowing a marker that peaked above the flowing current.
He blamed development along the creek banks for erasing gentler washouts where salmon could once escape the heavier parts of the river to lay their eggs. Now, he said, retaining walls had concentrated the storm waters into gushing torrents, leaving the fish with no place to spawn in heavier rain years.
“It doesn’t allow the water to spill over, to flood over,” Steiner said. “And so the fish lose that critical flood plain habitat to survive the storm events.”
Steiner pointed to nearby piles of rubble where the National Parks department recently tore down homes sitting along the creek. Steiner said his group’s offices would also eventually be removed, along with tens of thousands of yards of landfill. Turtle Island Restoration Network is currently involved in litigation against Marin County to create a moratorium on new development along the watershed.
Steiner peered out across the raging creek as a new round of rain drops began to tumble from above the canopy of trees. He said coho from the watershed have been used to help establish new populations across the state.
“If we lose this population,” Steiner said, “the chances are they will be gone forever from California.”