It’s not everyone who can literally claim to hold the future of an endangered species in their own hands. But for San Francisco District’s Ben White, that’s a statement of fact.
White, a fish biologist at Warm Springs Dam/Lake Sonoma, California, oversees the U.S. Army Corps of Engineers (USACE) Coho Broodstock Program for the last viable population of the central California coast coho salmon. He’s been working on the program for almost 12 years – the first seven working as a subcontractor through the state of California and the last five working directly for USACE.
On average, the program is releasing between 150,000 to 200,000 juvenile coho salmon a year – done at different life stages – into approximately 20 different tributaries of the Russian River that historically had wild runs of coho. Moreover, approximately 15 percent of those releases are tagged with an innovative passive integrated transponder (PIT) system. When combined with more than 80 antenna arrays stationed throughout the watershed, the complete system represents one of the most sophisticated monitoring efforts in the country.
The broodstock program reflects a multi-faceted response to the general impacts of various industries across most California rivers and streams as well as more targeted actions following the creation of Warm Springs Dam across Dry Creek in 1982.
“When we built the dam in the early ’80s, it stopped a lot of the coho from going back into traditional spawning areas,” said J.D. Hardesty, public affairs chief, San Francisco District. “What we’re doing with part of this broodstock program is in response to the biological opinion from the National Marine Fisheries Service. And, along with that, it is also creating habitat restoration on a 6-mile strip downstream of the dam along Dry Creek. We’re doing that so we’re creating places not only for the fish to spawn, but also when you have heavy rains and different things, there are back pools where they can sit and rest and relax and grow. They’re not likely to be eaten downstream; it increases their survivability.”
White pointed to the existence of “an original coho program” two decades ago, noting that it relied on “traditional hatchery techniques” that were unsuccessful over the long run.
“With this go-around, we sort of took the mitigation requirements, but we applied more of the conservation approach to the hatchery program,” he said.
White said that the program has three specific goals: preventing local extinction of coho salmon in the Russian River watershed; preserving the genetic integrity of the Russian River stock of coho in the watershed; and re-establishing natural runs of coho salmon back into a historical habitat.
The current program began with the collection of some of the last wild Russian River coho salmon as juveniles and bringing them into captivity.
“Between 2001 and 2003, we were able to collect between two and three hundred juvenile coho per year, to coincide with their three-year life cycle,” White said. “We brought those fish into captivity, where we can increase their survival by providing them with plenty of cold water, plenty of food, and eliminating predation. We then use those initial broodstock collections as our source population.”
He said that the fish were raised in large circular tanks at the hatchery and spawned, “according to a genetics breeding matrix to avoid inbreeding and maximize genetic diversity.”
“We take all of the offspring that we produce from these spawning efforts, and those are the fish that we re-introduce back into native habitat with the goal of them eventually spawning on their own,” he added.