Russian River Coho Now Dependent On Hatchery

High Country News looks at the Russian River’s coho salmon hatchery program, which — despite the very real problems associated with hatchery salmon — may be the coho salmon’s last chance in Central California:

Biologists noticed a precipitous decline among coho in the late 1990s. Numbers dwindled so drastically that in 2001 biologists from the U.S. Army Corps of Engineers and other state and federal agencies staged a rescue operation — capturing what wild fish they could find to begin a captive breeding program.

The Russian River Coho Salmon Captive Broodstock Program has released hatchery-raised coho since 2004. But, until this year, return rates have been poor. The fish are marked with small tags, roughly the size of a grain of rice, inserted into their abdomen, that trigger sensors when they return at the end of their life cycle. The winter of 2009 – 10 was the first year that more than 20 fish were observed returning to the Russian River. This winter, nearly 200 were seen, of the nearly 170,00 released. (Researchers estimate three to four times that number actually came back.) While scientists would like to see far more than that — around 3,000 would be great, they say — it’s a good start.

Hatchery programs are frequently criticized by environmental groups for artificially boosting fish numbers and masking the real cause of fish decline — loss of habitat. The truth is, no matter how well housed the breeding program, there is no substitution for good rivers.

“We think we can replace the wild salmon and the wild salmon habitat, but that simply isn’t true,” said Bill Bakke, of the Native Fish Society. “It’s not going to fix the real problem.”

Given the dire circumstances, however, a breeding program for the wild population is the best option. “It’s a desperate measure,” says Bakke, “a sign you’re at the end of your string.”

It’s never a good day when the word “desperate” is associated with fish restoration efforts.

Coho salmon are especially vulnerable to habitat loss because juvenile coho spend upwards of a year and a half in fresh water habitat before moving to the ocean (unlike juvenile chinook, which head to the ocean after several months).