'An Entirely Synthetic Fish': rainbow trout, ecological bully

'An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World'

by Anders Halverson

Yale University Press, 257 pp, $26

What if you reached the end of a rainbow and discovered, instead of a pot of gold, an ecological disaster? That's just what you might find if you're talking about rainbow trout, according to Anders Halverson, former reporter, sometime angler, Ph.D. in ecology.

In "An Entirely Synthetic Fish," Halverson probes the history of the artificial rearing and stocking of rainbow trout around the world. "Over the decades, rainbows have been bred to grow faster, mature earlier, and breed at different times of year," he writes. "Culturists have tried to select for disease resistance, fecundity, and even such things as color, shape and fighting ability." Things reached the point that in a 1939 report, the government's chief fish culturist could declare technology had made it possible to produce "an entirely synthetic fish."

The objective was to provide trout for anglers, and rainbow trout have been stocked in all 50 states and every continent except Antarctica. Rivers, lakes and reservoirs were poisoned to make way for rainbows, and rainbows were planted in many alpine lakes previously lacking fish. The result often was disastrous for native fish species and other life, Halverson writes.

More than a century passed before anybody thought to ask if stocking actually improved fishing. When biologists finally looked they found the opposite: Stocking hatchery rainbow severely depressed native populations and actually resulted in fewer trout for anglers.

That wasn't an easy sell to the public. When the Washington Department of Fish and Wildlife proposed cutting hatcheries, there was immediate public outcry. That led Bern Shanks, former department director, to observe "that a fish hatchery is what you get 'if you cross a sacred cow with a military base.' "

Now the trend is the other way: Hatcheries are being closed, fewer rainbow stocked, and some populations are being eradicated to restore the natural ecology.

Yet concerning rainbows, things aren't always black and white. Halverson acknowledges anglers are upset over the new trend and it's not fair their taxes and license fees should pay to eradicate trout. He notes also that stocked trout support a sizable industry, and many communities depend upon them.

Where does that leave us? Halverson suggests those who now oppose stocking rainbows argue with the same zeal as those who favored it a century earlier — and "they, too, were sure they were doing the right thing for the world."