The trout were obviously rainbows but looked unlike any I had caught previously: They were dark--almost black--with a bright orange-tipped dorsal fin. Beautiful fish. But what were they? Native trout adapted to the volcanic streambed? Hatchery fish stock from afar? Hybrids?
The answer is not easily found, in large part due to reasons described in Anders Halverson's An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World.
Halverson documents the global spread of a beautiful wild fish once confined to waters of the American West. It's an amazing and sometimes exasperating story: People believed the best way to improve "rivers" was by stocking them with "better" species like rainbow trout, giving rise to a massive hatchery system that continues to produce trout by the millions to this day.
For years, the stocking of non-native fish was viewed as sound conservation practice--a way to sustain fishing while rivers underwent dramatic changes. Even John Muir supported trout stocking in Sierra Nevada lakes.
Adding to fishery dilemmas was our nation's surprisingly complicated attitudes towards fishing. Early Puritans considered it an idle activity that led to sin and damnation, but later politicians viewed it as a "manly" activity that could keep urban citizens from growing too soft.
Factors like these led to enthusiastic, and "science based" fish stocking, often at the expense of native species. Halverson's most dramatic example was the mass poisoning of all native fish in the upper Green River to make way for an introduction of trout. At the time, this was considered scientifically defensible.
And that, perhaps, suggests the real issue here: that conservation is so often about values more than science, a point Halverson's book makes repeatedly. Even today, the push to remove non-natives and restore native trout rests on a value for native ecosystems more than scientific necessity.
Writes Halverson: "I do believe, though, that those who promote the conservation and restoration of native species should do so with a good understanding of history and a concomitant sense of humility. People have been a part of this world for a long time. There's no going back to the way it was, even if it were possible to define it. Reading through the letters and public pronouncements of the men who were most responsible for spreading nonnative species like rainbow trout throughout the world in the nineteenth century, I have been struck by the similarity of the rhetoric of those who promote native species restoration today. They, too, were sure they were doing the right thing for the world."
Yes. That's it exactly. One hopes that, indeed, humility and conservation history could help inform our many pressing conservation issues today. Halverson's book shows that many societal factors have always informed our values about the natural world--a fact that continues to influence conservation to this day. --Matt Miller