Author details how rainbow trout conquered the world

DALLAS (Reuters Life!) - In the Dallas/Fort Worth Metroplex fishermen can catch their fill of rainbow trout during the relative cool of the winter months in several stocked dams and at least one stream.

The cover of Anders Halverson's "An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World". REUTERS/Yale University Press

Rainbow trout can also be pursued in South Africa and even Malawi, countries where they have been featured on postage stamps. They are found on every continent except Antarctica.

That makes this spotted trout, with its emblematic red horizontal stripe, as successful a colonizer as cattle and corn and its ubiquity derives from the same source: humanity’s love affair with it.

It is an affair detailed by Anders Halverson, a journalist, angler and scientist, in “An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World.”

Rainbows are native only to the Pacific Rim, from Mexico to Russia’s Far East. But they are coveted for their perceived fighting prowess and beauty. Hatchery-reared rainbows have been distributed since the late 19th century to every U.S. state and around 80 countries around the world.

Along the way, Wyoming in 1962 launched a massive poisoning campaign in the Green River watershed to kill off the native fish and make way for the rainbows. U.S, military aircraft have also made trout drops into remote, fishless lakes.

Many U.S. states are now rolling back decades of stocking policies and “trout wars” have broken out in places such as South Africa, as the conservation paradigm shifts to the preservation of native species.

Still, for each American that is born, 20 rainbow trout are still stocked in waterways at public expense, including in unlikely urban locations such as Dallas.

Halverson spoke to Reuters about his book from his Colorado base.

Q: You note some of the unintended consequences of introducing non-native species, such as how rainbow trout have wreaked havoc on frog populations in high-altitude lakes that were fishless before. Do you fear that other undiscovered ecological catastrophes are underway from such practices?

A: “I’m sure there are many effects that we have no idea about right now ... there are effects even on the finches and bats nearby because the rainbow vacuum up all the larvae. Then there’s no hatch of flies for the bats or the finches. So it ripples out to the terrestrial system as well.”

Q: Defenders of trout stocking policies often argue that they are being put in “tail-waters,” which are colder than they would naturally be because such flows are released from the bottom of dams. The argument is that warm-water fish like bass can’t survive anyway, so you might as well throw something in. Your response to that?

A: “I think there is something to that to be honest. We’ve changed these environments so drastically that really they aren’t native habitats anymore. There is not a great deal of harm in stocking them in these habitats which are already modified ... I think the most insidious effect is this notion that all fish come from hatcheries so it may change people’s mentality. But in general I don’t think there is a great deal of harm from stocking them into these habitats that are already drastically modified.

“But the other thing you have to bear in mind is that they are frequently and much more often stocked into streams and rivers where there is plenty of native species and that’s really I think where the controversy comes from.”

Q: Rainbows have often been preferred to native fish because of their readiness to take a fly. But in places such as South Africa, anglers have discovered that native species such as yellow fish offer just as much sport to fly fishermen. Can you think of any here in America, of a previously disparaged native fish that people suddenly realized had sporting value?

A: “The whole notion of fishing for native fish has really taken off ... Just as birders keep a life list, there’s a group of fishermen out there who keep a list of native species that they’ve caught.”

Q: You have taken up fishing again after a hiatus. How’s that going?

“I like to go catch the rainbows but I’ve become really obsessed with filling out my life list as well ... to me that’s been the best part.

“I fished because I see it as an escape from civilization and technology and industrialization just like everyone else. And then finally I sort of recognized the paradox that these fish are in fact very much a product of industrialization and technology and civilization and that’s sort of what drove me to write the book.”

Editing by Patricia Reaney