Efficient machines can mark millions of salmon

UNDERWOOD, Skamania County — In the highly engineered environment of the modern Columbia River, even the Pacific Northwest's iconic salmon is produced in assembly-line fashion.

Lately, the mechanization has reached a new level of efficiency at the Spring Creek National Fish Hatchery. A series of three state-of-the-art machines makes it possible for the hatchery to clip the adipose fin of every finger-size tule fall chinook salmon.

That's 15 million fish.

"It wasn't feasible to try to hand-mark that number of fish," said Larry Marchant, who manages the hatchery for the U.S. Fish & Wildlife Service. "Mass-marking trailers really speeds that process up."

Three of those automated trailers, priced at about $1.1 million each, now supplement the work of 40 temporary employees working two shifts to snip off the adipose fins of as many fish as possible. The goal is to make sure every fish produced at Spring Creek is marked so that fishermen in the river and on the ocean will be able to distinguish finless hatchery-raised "keepers" from their wild-spawned cousins, which they throw back so they can continue toward their spawning grounds.

Biologists generally see the fatty fin, on the fish's back just in front of the tail, as something akin to the human appendix.

It is quickly and efficiently snipped in the automated trailers.

Using sophisticated computer-aided photography, the machine sorts the sub-yearling fish by length. Pneumatic gates divert the fish in tubes toward one of six snipping lines. Each fish then slides down to the end of a tiny chute, where an automatic clipper precisely clips the fin.

"The success rate is extremely high, and mortality is extremely low," Marchant said. "Essentially, there's no mortality that we see."

Even better, the automated trailers turn out 90,000 fin-clipped fish every day.

That's about twice the rate accomplished by two shifts of a dozen workers who must spend the day hunched over watery work stations for $11.01 an hour.

Federal fishery managers believe the Rube Goldberg-style automated contraption is the wave of the future for two essential reasons: the tenuous state of wild-spawning native fish, combined with the need to feed the voracious appetite of commercial, sport and tribal fishermen for salmon and steelhead raised in hatcheries.

Federal fish managers originally built the Spring Creek hatchery in 1901 to offset overfishing that had by then taken a serious toll on the once-abundant runs of wild salmon returning to the Columbia River basin.

In later years, a flurry of federal dams further eroded wild salmon populations.