Local creek study nets positive results
Photo by Gordon Becker, CEMAR. This 24-inch steelhead trout was found in an undisclosed location of Sonoma Creek in Glen Ellen. It is one, although not the only, indicator of the health of the creek ecosystem.
Previous population studies have shown that steelhead trout do indeed spawn in Sonoma Valley, but the new study, a partnership between Sonoma Ecology Center (SEC), the Center for Ecosystem Management and Restoration (CEMAR), and the Southern Sonoma County and Sotoyome Resource Conservation Districts (RCDs), hoped to answer more detailed questions about these fish that were once so abundant in local creeks.
“This data we are collecting is considered baseline data,” said Rebecca Lawton, Research Director with the SEC. The study has been designed to gather data specifically on juvenile steelhead, called smolt, beginning their migration to the sea. “As far as I know, we don’t have previous smolt count data [in Sonoma Valley]. If we get any idea of what’s succeeding now, then we can watch over the next 10 years and beyond to see what’s successful in the future,” said Lawton.
The project involves three veteran fish biologists and a rotating roster of volunteers, who installed temporary fish “traps” in the creek at two locations near Kenwood and Glen Ellen. Daily, biologists visit each trap – a screened box that ensures fish and other animals are not harmed – and take note of the findings before releasing the animals. It is illegal to fish for or handle steelhead in all Sonoma Valley streams without the proper permit, and Lawton said this study was made possible only through the unique partnership between SEC and CEMAR and the RCDs.
Biologist Jeff Hagar has been looking at fish for decades, but he wasn’t sure what to expect from Sonoma Creek. “Many people write off their local streams and assume that they are degraded and don’t support interesting fish life,” said Hagar. However, he and the team have been impressed by the results so far. “We basically achieved our main project objective the first day by finding a number of juvenile steelhead including smolts,” said Hagar. “This indicates there may still be a viable steelhead population in the creek.”
In addition to numerous smolts, Lawton said the traps have turned up some other exciting finds, like the rare California freshwater shrimp. According to Lawton, freshwater shrimp are only found in Napa, Sonoma and Marin counties, and therefore are even less widespread than the steelhead they’re trapping. Also Pacific lamprey – an ancient creature, not quite fish and not quite eel, and the namesake of the Eel River – have been found in the traps. Lamprey were once a major food source for Native Americans and settlers, and are now much diminished in numbers. The traps also have captured hundreds of California roach, a native species that prefers warmer waters than steelhead. Lawton said that finding smolt in addition to roach is a positive sign that the steelhead are finding the cooler pools in the area in which to summer over.
“We know the big guys come back,” said Lawton, referring to the grown steelhead like the 24-inch male, nicknamed “Ernie,” who was caught in the trap near Glen Ellen. “But to see the young, and to find the ‘out-migrants’ is really exciting.” Lawton said that how smolts start their journey is important to ensuring how they will return, likening the importance of good smolt habitat to the importance of good schools for kids going off to college. “We want to send well-prepared, fortified fish out to the ocean so they make it in the big world.”
Lawton said that she and many local residents know the creeks are still not as healthy as they used to be, in terms of sediment and diversity of habitat. SEC has various studies underway monitoring stream health parameters, like water level and temperature. “But we are thrilled to be finding interesting fish life in our streams,” said Lawton.
“If the fish themselves don’t intrigue people, I understand that, because different people have different values. But our aquatic species are like canaries in a coal mine. If we protect our stream habitat and ensure it’s doing well, we positively affect the diverse species in the creek. Protecting cool stream corridors helps keep water temperatures down and aquatic diversity strong. If we have ‘green’ streams with populations that are doing well, we are essentially protecting our home from world change. This is important to our very survival and comfort. Everyone can relate to that.”
Although this particular project wraps up this summer, Lawton said that this is just the start of monitoring rather than the end. Data collected by the Sonoma Creek fish study will help develop a model for a regional fish monitoring program.
Sarah Phelps is an editor and reporter. She was raised in Kenwood and has a BA from Loyola Marymount University.