Wednesday, March 3, 2010

One Strange Fish Tale

By Peter Schmidt

Behold the regal rainbow trout, dappled denizen of deep lake and rushing river, fierce hunter of fish and fly—and prize of pork-barrel politics, invigorator of men, eradicator of native species, payload of numerous bombing missions.

An angler can catch a lot of rainbow trout and yet have no clue what a remarkable force of nature—and mankind—the creatures truly are. Anders Halverson, a research associate at the University of Colorado's Center of the American West, hoists them up for close inspection in a book just released by Yale University Press: An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World.

Few one-that-got-away stories sound nearly as improbable as his account of how our species, Homo sapiens, spread the fish species, Oncorhynchus mykiss, beyond its native range.

Consider that as of the 1870s, the rainbow trout and its sea-run variant, the steelhead, lived only along the Pacific Rim, from California to Russia's Kamchatka Peninsula. Since then, Halverson says, the fish "have been introduced to every state in the United States and to at least 80 different countries on every continent except Antarctica," an expansion of range that took humans, corn, sheep, and dogs thousands of years to achieve.

Halverson offers statistics that illustrate how much humans are still involved in the spread of rainbow trout: For each of the roughly four million people born in the United States each year, he says, state and federal hatcheries stock about 20 of the fish in public waters. Most of them being mature, they weigh a total of about 25 million pounds.
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Why make such an investment in spreading this one species of fish? It grows rapidly in hatcheries and withstands warmer waters and more-difficult conditions than other trout. Perhaps more important, Halverson says, the stocking of rainbow trout—which fight hard and leap acrobatically when hooked—has "satisfied a powerful human need": the primal urge to seek out and battle prey.

Halverson's book is a microhistory, an examination of America's involvement with a favored fish that sheds light on broader truths regarding our recent relationship with the natural world.

He says he fished for stocked rainbow trout while growing up in Colorado but eventually got bored with the pursuit and thought little of the fish until he became a graduate student in aquatic ecology at Yale University, where he earned his doctorate in 2005. At Yale "I came to realize there is a real paradox to the way so many fisheries are managed these days," he says. "Like most fishermen, I see fishing as a way to escape civilization and industrialization, and a way to sort of make peace with the natural world." Yet most rainbow trout, being either the products of hatcheries or the descendants of hatchery fish, "are in many ways a product of that industrialization."

He decided to write a book examining the artificial spread of the rainbow trout and obtained a National Science Foundation grant to help finance the undertaking. He initially expected the project to be mainly an exercise in muckraking (he had worked as a newspaper reporter before going to graduate school). But "the more people I met and the more people I interviewed," he says, "the more I realized what a complex topic this is." Although he came across case after case in which efforts to spread the trout led to environmental disasters, his book generally does not paint those involved as fools or villains.

When it comes to government policy regarding trout, he says, "there are a lot of issues for which there are no clear answers." He points to the dilemma posed by rainbow trout's ability to mate with the increasingly rare—and unhealthily inbred—cutthroat trout of the American West. Such interbreeding is causing cutthroats to become even rarer as a distinct species, but the purebred cutthroat population is having so much trouble surviving on its own that hybridization might represent the single best hope of passing the fish's genes along to future generations. It is unclear whether the long-term survival of cutthroats requires keeping rainbows at a distance or bringing the two species together.

The oddest specimens in An Entirely Synthetic Fish are the people. They include Livingston Stone, a New Hampshire pastor who abandoned the pulpit to raise brook trout on a fish farm, then ventured to California in the 1870s, initially to set up a federal salmon hatchery in the Sacramento River Valley. He encountered the rainbow trout and ended up propagating that species in a hatchery on the McCloud River, where he lived under threat of attack by outlaws and members of the Wintu tribe. In one report on his activities, he remarked, "With tarantulas, scorpions, rattlesnakes, Indians, panthers and threats of murder our course here is not wholly over a path of roses."

Among others described in Halverson's book is Al Reese, a crop duster and barnstormer who in the late 1940s helped persuade California's Department of Fish and Game to drop rainbow trout into mountain lakes from the air. (He tested the fishes' ability to survive the trip partly by holding live specimens out a car window at 70 miles per hour.) The state agency recruited World War II pilots and purchased surplus military airplanes to dump the fish, generally from about 200 feet. Many of the trout died on impact with the water or ended up stuck in trees, but enough survived to inspire the agency to similarly drop turkeys, partridges, and even beaver (in burlap sacks attached to parachutes). About 50 years later, the agency learned that it had gone overboard with its fish-bombing runs, inadvertently ridding lakes of rare frogs, which the fish had devoured, and filling some lakes with so many trout that their growth was stunted from too much competition for food.

California fish-and-game officials are hardly the only ones who eventually altered trout-stocking policies in response to evidence of money wasted or doing more harm than good.

The book devotes a chapter to the U.S. Fish and Wildlife Service's decision in 1962 to deliberately poison the Green River in Utah and Wyoming to wipe out the native fish and make room for rainbows. At the time, few in the agency questioned the idea of pouring huge amounts of the piscicide rotenone into a body of water. Since 1952 federal and state fisheries managers had used the chemical, which kills anything with gills, to clear the way for rainbow trout and other game fish in a long list of rivers and lakes around the nation, even within national parks.

A few scholars at Colorado State University and the University of Utah spoke out against the Green River plan and subsequently complained of efforts by state and federal agencies to shut them up by threatening to cut off grants to their institutions. Many of those involved in the river poisoning lived to regret it, for it ended up being a disaster for both the environment and public relations.

The project's planners assumed they would be able to keep the keep the river from carrying the rotenone into Dinosaur National Monument park by having workers neutralize the poison upstream from the park with potassium permanganate, but they were wrong. When dead fish turned up in the park, the Fish and Wildlife Service found itself in the cross hairs of the National Park Service. Perhaps even more important, about three weeks after the incident, Rachel Carson published Silent Spring, helping spawn an environmental movement that barraged officials in Washington with angry letters about the Green River kill.

The secretary of interior at the time, Stewart Udall, responded by curbing the use of rotenone by federal agencies and calling for the welfare of unique species to be a "dominant consideration" in such projects from then on. All four of the chief so-called trash fish that the Green River poisoning sought to kill—the humpback chub, the bonytail, the razorback sucker, and the Colorado pikeminnow—now have a place on the federal endangered-species list. The federal government has spent more than $100-million trying to save them.

An Entirely Synthetic Fish recounts many other governmental attempts at improving nature that went awry. In the 1960s, for example, researchers discovered that stocking a river with hatchery trout can decimate the wild trout population and actually leave it with fewer trout over all; the hatchery fish aggressively compete with the locals for food, and many end up being eaten themselves because they seem to associate the shadows of predators with those of hatchery workers tossing kibble. Beginning in the late 1980s, the Colorado Division of Wildlife inadvertently unleashed trout epidemics by stocking rivers with rainbows infected with parasite-born whirling disease, which leaves its victims disfigured and prone to swimming in tight circles.

The book also compellingly traces how the nation's attitudes toward fishing have varied over time. In the 17th century, the leaders of the Massachusetts Bay Colony regarded fishing with a hook and line as an exercise in idleness deserving punishment. During and just after the American Revolution, fishing suffered a similar image problem, thanks to its association with the English aristocracy. Beginning in the mid-1800s, however, interest in sport fishing boomed as it gained status as a diversion for the wealthy and came to be viewed as a pursuit that helped keep men virile and in touch with nature. Politicians eager to take credit for bringing hatchery jobs and better fishing to their states happily supported federal efforts to stock waters with game species.

Throughout much of America, one can still encounter the absurd sight of fishermen gathered on riverbanks next to hatchery trucks, hoping to catch naïve rainbow trout minutes after they are stocked. While not exactly shooting fish in a barrel, perhaps no other experience comes as close.

For his part, Halverson is attempting to restore the populations of rarer species of trout by, counterintuitively, encouraging people to fish for them. Taking a cue from the culture of birdwatchers, many of whom will travel long distances to add to their "life list" of species they have seen, he has set up a Web site that encourages anglers to catch and release as many species as they can. His logic is that if enough people roll into small towns and say they are out to hook rare fish species X or Y, the local chambers of commerce will get word, and new constituencies will be created to lobby for the fish's restoration.

Writing An Entirely Synthetic Fish has renewed his own interest in angling, both for rainbows and for other trout, Halverson says. "I actually love fishing again. You pick one of these rainbows up, and it is just a book that says so much about us."

2 comments:

請客 said...

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宗家 said...

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