The global rainbow invasion and a synthetic paradox

April 9, 2010

I’ve pursued and caught rainbow trout in many places, some of them unlikely. I caught hundreds in South Africa when I was based there. Here in the United States, I’ve had them hit my flies and brought them to my net in Texas and Oklahoma. I’ve done the same in the mountain states of New Mexico, Colorado, Wyoming and Utah, states that, at least in the popular imagination, are more associated with trout and rainbow in particular.

I also managed to land one magnificent rainbow in Alaska during a reporting trip there in 2008.  Of the hundreds of rainbow trout that I have caught, that one stands out because it was the only one that was swimming where it belonged.


(Photo: Author Anders Halverson details the rainbow trout’s unnatural recent history. Photo credit:  Ginna J. Halverson)

The improbable history of the rainbow’s global conquest is detailed in “An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World,” by Anders Halverson, a journalist, angler and scientist. You can see my interview with him about the book here.

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.

Halverson’s book certainly raises some interesting questions. He says that part of his motivation for writing it was spawned from his realization that there was a paradox in his own passion for fishing for rainbows. For many anglers (myself included) there are many appeals to fly fishing, but one that is high up on most lists is the notion that it reconnects you to nature.  As Halverson notes, a stocked rainbow is in fact a product of the technology and industrialization that anglers are seeking to escape when they wade into a stream or approach a rural dam and cast a fly into the water. So an experience that many find “natural” is in fact at least on some levels “synthetic.”

Of course, there are wider issues at play here than synthetic outdoor pursuits. The worldwide distribution of rainbows is one of the countless examples of humanity aiding the spread of invasive species. Rainbows have wreaked havoc on frog populations in fishless lakes where they have been deposited. Native fish populations have also suffered from their sudden presence.

In many places, stocking policies are being rolled back as the conservation paradigm swings back to an emphasis on native species. But of course, many native species are now found in regions and water bodies where their habitats have been profoundly altered in one way or another by humanity.

It leads one to ask: are there many really “natural” ways left to enjoy the outside world?

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