The Best American Science and Nature Writing 2017 Page 18

  The problem, though, ran deeper than transient politics. People had long come to national parks to experience the eternal—to get a glimpse, however deceptive, of nature in its stable, “unimpaired” state. The inconvenient truth of climate change made it more and more difficult for the Park Service to offer that illusion. But no one knew what the national parks should offer instead.

  When Nate Stephenson was six years old, his parents fitted him with boots and a hand-built wooden pack frame and took him backpacking in Kings Canyon National Park. For most of the 53 years since, Stephenson has been hiking the ancient forests of the Sierra Nevada. “They’re the center of my universe,” he says. Soon after he graduated from UC Irvine, he packed up his Dodge Dart and fled Southern California for a summer job at Sequoia National Park. Now he’s a research ecologist there, studying how the park’s forests are changing.

  While park managers are often consumed by immediate crises, researchers like Stephenson have the flexibility—and the responsibility—to contemplate the more distant future. In the 1990s this long view became deeply disturbing to him. He had always assumed that the sequoia and foxtail pine stands surrounding him would last far longer than he would, but when he considered the possible effects of rising temperatures and extended drought, he wasn’t so sure—he could see the “vignette of primitive America” dissolving into an inaccessible past. The realization threw him into a funk that lasted years.

  “I was a firm believer in the mission of the Park Service,” Stephenson remembers, “and suddenly I saw that the mission we had was not going to be the same as the mission of the future. We could no longer use the past as a target for restoration—we were entering an era where that was not only impossible but might even be undesirable.”

  Stephenson began what he calls a “road show,” giving pres-entations to Park Service colleagues about the need for a new mission. Somewhat mischievously, he proposed a thought experiment: What if Sequoia National Park became too hot and dry for its eponymous trees? Should park managers, who are supposed to leave wild nature alone, irrigate sequoias to save them? Should they start planting sequoia seedlings in cooler, wetter climes, even outside park boundaries? Should they do both—or neither?

  His audiences squirmed. Leopold had left them no answers.

  On a late September day in Sequoia National Park, the sky is clear, blue, and, thanks to a brisk wind, free of smoke from the wildfire burning just over the crest of the Sierra Nevada. Stephenson and his field crew are finishing a season of forest surveys, adding to a decades-long record of forest health. In their lowest-elevation study sites, below the sequoia zone, 16 percent of the trees have died this year, approximately tenfold the usual rate. “It’s about what you’d see after a low-grade wildfire,” says Stephenson. Weakened by years of drought, many of the low-elevation trees are dying from insect attacks. At higher elevations, in the sequoia stands, several old giants have dropped some of their needles to combat drought stress; a few that were already damaged by fire have died. “It’s not ‘The sequoias are dying,’ ” Stephenson emphasizes. “The sequoias are doing relatively well. It’s the pines, the firs, the incense cedars—the whole forest is affected.”

  The current drought may be a preview of the future, but the trouble with climate change—at Sequoia and elsewhere—is that many of its effects are hard to predict. Average temperatures at Sequoia will rise, and snow will give way to rain, but it’s not clear whether total precipitation will increase or decrease, or whether the changes will be gradual or abrupt. “We don’t know which scenario is going to play out,” says Sequoia and Kings Canyon superintendent Woody Smeck. The Park Service can no longer recreate the past, and it can’t count on the future. Instead it must prepare for multiple, wildly different futures.

  In 2009, Park Service director Jonathan Jarvis assembled a committee of outside experts to reexamine the Leopold Report. The resulting document, “Revisiting Leopold,” proposed a new set of goals for the agency. Instead of primitive vignettes, the Park Service would manage for “continuous change that is not yet fully understood.” Instead of “ecologic scenes,” it would strive to preserve “ecological integrity and cultural and historical authenticity.” Instead of static vistas, visitors would get “transformative experiences.” Perhaps most important, parks would “form the core of a national conservation land- and seascape.” They’d be managed not as islands but as part of a network of protected lands.

  The report is not yet official policy. But it’s the agency’s clearest acknowledgment yet of the changes afoot and the need to manage for them. Exactly what that management looks like isn’t certain, and much of it will be worked out park by park, determined by science, politics, and money. Some parks have already gone to great lengths to resist change: Cape Hatteras National Seashore, for instance, spent almost $12 million to move a famous lighthouse a half mile inland. But such dramatic measures are rare and likely to remain so; the Park Service budget today is about what it was in 2008.

  Instead many parks are looking to boost their tolerance for change, adapting their own infrastructure and helping their flora and fauna do the same. At Indiana Dunes National Lakeshore, scientists are searching the oak savannas for cooler microclimates into which the Park Service might transport the endangered Karner blue butterfly, which has been all but driven from the park. In Glacier, biologists have already captured bull trout and carried them in backpacks to a higher, cooler lake outside their historic range. The idea is to give the fish a refuge both from climate change and from invasive lake trout.

  At Sequoia, Stephenson wants park managers to consider planting sequoia seedlings in a higher, cooler part of the park—to see how the seedlings fare, and also how the public would respond to experimenting with the icons. “We have to start trying things,” he says.

  At Assateague, while Ennis’s successors prepare the parking lots and toilets for change, Liz Davis, the chief of education, is preparing the park’s younger visitors. In 25 years at Assateague she has introduced countless school groups to the seashore. When elementary students visit, she takes them to the beach, shapes a model of the island out of sand, and throws a bucket of seawater across it to show how the island shifts. Then she turns the model over to the kids: Where would they put the parking lots and campgrounds? How about the visitors’ center? “They get really into it,” she says, laughing. “They’ll say, No, no, don’t put the new ranger station there, it’ll get washed away!”

  Like the Park Service, visitors must learn to accept that their favorite park might change. “People ask, Will I still be able to enjoy it? Will my kids and grandkids be able to enjoy it?” Davis says. “The answer is yes, they will. They might not enjoy it in the same way, and they might not get here the same way. But they will still be able to enjoy it.”

  TOM PHILPOTT

  How Factory Farms Play Chicken with Antibiotics

  FROM Mother Jones

  The massive metal double doors open and I’m hit with a whoosh of warm air. Inside the hatchery, enormous racks are stacked floor to ceiling with brown eggs. The racks shake every few seconds, jostling the eggs to simulate the conditions created by a hen hovering atop a nest. I can hear the distant sound of chirping, and Bruce Stewart-Brown, Perdue’s vice president for food safety, leads me down a hall to another room. Here the sound is deafening. Racks are roiling with thousands of adorable yellow chicks looking stunned amid the cracked ruins of their shells. Workers drop the babies into plastic pallets that go onto conveyor belts, where they are inspected for signs of deformity or sickness. The few culls are euthanized, and the birds left in each pallet are plopped on something like a flat colander and gently shaken, forcing their remaining shell debris to fall into a bin below. Now clean and fluffy, the chicks are ready to be stacked into trucks for delivery to nearby farms, where they’ll be raised into America’s favorite meat.

  Not long ago this whole protein assembly line might have been derailed if each egg hadn’t been treated with gentamicin, an
antibiotic the World Health Organization lists as “essential” to any health-care system, crucial for treating serious human infections like pneumonia, neonatal meningitis, and gangrene. But the eggs at Perdue’s Delmarva chicken production farms have never been touched by the drug.

  That’s extremely uncommon in corporate factory farming. Currently, livestock operations burn through about 70 percent of the “medically important” antibiotics used in the nation—the ones people need when an infection strikes. Microbes that have evolved to withstand antibiotics now sicken 2 million Americans each year and kill 23,000 others—more than homicide. Even though public health authorities from the Food and Drug Administration and the Centers for Disease Control and Prevention have long pointed to the meat industry’s reliance on anti­biotics as a major culprit in human resistance to the drugs, the FDA has never reined in their use.

  I’m in Delmarva, the peninsula composed of pieces of Maryland, Virginia, and Delaware, because it is Big Chicken country—the teeming barns that dot its rural roads churn out nearly 11 million birds per week, almost 7 percent of the nation’s poultry. And Perdue, the peninsula’s dominant chicken company and the country’s fourth largest poultry producer, has set out to show that the meat can be profitably mass-produced without drugs. In 2014 the company eliminated gentamicin from all its hatcheries, the latest stage of a quiet effort started back in 2002 to cut the routine use of antibiotics from nearly its entire production process.

  In 1928, Scottish biologist Alexander Fleming discovered a mold-based compound dubbed penicillin that could kill common microbes that cause dangerous infections. But even as they began to revolutionize medicine, antibiotics had a fundamental flaw. While collecting the 1945 Nobel Prize in medicine, Fleming warned that it’s “not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them.”

  When an antibiotic attacks a colony of bacteria, the great bulk of the bacteria die or can no longer reproduce, and the infection is cured. But a few rogue microbes can withstand the assault and pass their hardy genes on to their progeny. If you unleash the same antibiotic on the same bacteria over a long enough time, you’ll create a bacterial strain that can thumb its nose at the drug. And it isn’t just turbocharged Darwinism that makes our antibiotics so vulnerable. Through a process called “conjugation,” genes—including ones that have become resistant to particular antibiotics—can bounce from one microbe to another.

  Though we’ve known this for more than 70 years, doctors have too often treated antibiotics as a sturdy crutch, not a delicate tool to be used sparingly. The CDC estimates up to half of all antibiotics used in U.S. medicine are improperly prescribed, speeding up resistance. But that is nothing compared with how recklessly they’ve been used in factory farms. When you treat thousands of chickens in a huge enclosed barn with, say, steady doses of tetracycline, you risk generating an E. coli bug that can resist the antibiotic you threw at it, and that bug’s new superpowers can also jump to a strain of salmonella that happens to be hanging around. Now two nasty pathogens that plague humans have developed tetracycline-resistant strains.

  And the worst part is that antibiotic use in factory farms isn’t mostly a matter of keeping animals healthy. In 1950 a pharmaceutical company called American Cyanamid—now part of Pfizer—wanted to see if giving chickens vitamin B12 made them fatter, so it ran some experiments. The idea seemed to work. But the researchers soon discovered it wasn’t the vitamin that had fattened the birds; it was traces of an antibiotic called aureomycin. (B12 can be a byproduct of aureomycin production; the vitamin researchers used had come from making the antibiotic.)

  This discovery revolutionized meat production. Adding a dash of antibiotics to feed and water rations magically made birds, pigs, and cows grow plumper, saving on feed costs and slashing the time it took to get animals to slaughter. In 1977 the General Accounting Office reported that “the use of antibiotics in animal feeds increased approximately sixfold” between 1960 and 1970. “Almost 100 percent of the chickens and turkeys, about 90 percent of the swine and veal calves, and about 60 percent of the cattle raised in the United States during 1970 received antibiotics in their feed.”

  In turn, antibiotics helped launch the rapid industrialization of chicken production. In 1950, at the dawn of the antibiotic revolution, 1.6 million U.S. farms were raising about 560 million birds. By 1978 only 31,000 mostly large chicken farms remained, and they were cranking out more than 3 billion birds.

  Meanwhile a steady accumulation of scientific research revealed a mounting public health crisis. At the end of the ’60s, a scientific committee in the United Kingdom found that using antibiotics in animal feed produced large numbers of resistant bacteria that could be transmitted to people. Similar findings were reported by an FDA task force in 1972, and as a result the agency issued regulations requiring drug manufacturers to prove their agricultural products didn’t contribute to resistance. If they couldn’t, their approval to sell the drugs would be revoked.

  So the Animal Health Institute, a trade group of animal-pharmaceutical manufacturers, contacted Stuart Levy, a young Tufts University researcher who specialized in antibiotic resistance. The group wanted Levy to feed tiny daily doses of antibiotics to chickens and see if the bacteria in their guts developed resistance. The drug companies were convinced the results would “get the FDA off their backs,” says Levy.

  Levy found a family farm near Boston and experimented on two flocks of chickens. One got feed with small amounts of tetracycline. The other went drug-free.

  Within 48 hours, strains of E. coli that were resistant to tetracycline started to show up in the manure of the birds fed drugs. Within a week, nearly all the E. coli in those birds’ manure could resist tetracycline. Within three months, the E. coli showed resistance to four additional anti­biotics the birds had never been exposed to: sulfonamides, ampicillin, streptomycin, and carbenicillin. Most striking of all, researchers found that E. coli resistant to multiple antibiotics was appearing in the feces of the farmers’ family members—yet not in a control group of neighbors.

  The results, published in the New England Journal of Medicine, were so stunningly clear that Levy thought they would prompt the industry to rethink its profligate antibiotic use, or at least inspire the FDA to rein it in. But the industry rebuffed the study it had bankrolled, questioning the validity of the data, Levy says. In 1977 the FDA proposed new rules that would have effectively banned tetracycline and penicillin from animal feed, but the House agriculture appropriations subcommittee, led by agribusiness champion Representative Jamie Whitten (D-Miss.), ordered the FDA to wait, “pending the outcome of further research.”

  Those proposed 1977 bans remained in limbo for decades, dormant but officially “under consideration”—until 2011, when the FDA finally ditched them and let companies take a voluntary approach to curtailing antibiotic use. Meat producers were given until the end of 2016 to wean themselves from antibiotics. At that point, the agency warned, it would consider banning certain antibiotics if its light-handed approach did not “yield satisfactory results.” However, the plan also gave industry a gaping loophole: while it suggested livestock producers should no longer use human-relevant antibiotics as growth promoters, it left companies free to use them to prevent disease.

  Unsurprisingly, the industry’s appetite for antibiotics has remained voracious. According to the FDA’s latest figures, antibiotic use on U.S. farms surged 13 percent between 2009 and 2014, even as overall U.S. meat production leveled off. In 2014 livestock operations used 20 million pounds of antibiotics important to humans—while doctors used about 7 million pounds.

  A few years ago I came across a Consumer Reports study of bacteria on supermarket chicken. The magazine had found that Perdue chicken was far less likely to carry bacteria resistant to more than one antibiotic than chicken from other producers, including Tyson and Foster Farms. Consumer Reports said Perdue’s good showing marked the “fir
st time since we began testing chicken that one major brand has fared significantly better than others across the board.” When I asked Urvashi Rangan, a Consumer Reports researcher, why Perdue had done so well, she credited the company’s policy against using growth-promoting antibiotics.

  As a longtime critic of industrial agriculture, I was surprised to learn Perdue had such a policy. I knew it was a leading supplier of chicken labeled “no antibiotics ever,” but this study showed that even its conventional chicken was far less likely to carry resistant bacteria than such chicken from other producers. Could it be that this one company was tacking against industry norms and taking the science seriously?

  Historically, most birds bound for market not only got antibiotics in their feed but were dosed with drugs before they even hatched. Bruce Stewart-Brown, who is 59 years old and trim, explains why as we walk through the hatchery. About 40 years ago, a herpes virus called Marek’s disease began to attack chickens, and vets discovered that vaccinating the chicks while they were still in their shells could inoculate them for life. But when you penetrate eggs with a needle loaded with the vaccine, the tiny hole you create opens a door, welcoming bacteria in. To solve this problem, hatcheries added small amounts of gentamicin to the vaccine to prevent bacteria from getting a foothold in the bird.

  This method was so efficient that decades later the hatchery ended up being the trickiest place for Perdue to remove antibiotics from production. The company gets its eggs from contract breeders, and in the past eggs often arrived covered in bacteria-laden manure. Now Perdue requires its breeders to deliver clean eggs. Perdue also used to mix its Marek’s vaccines in the middle of a less-than-pristine hatchery. Today the company mixes the drugs under sterile laboratory conditions and injects clean, antibiotic-free vaccines into clean eggs. It took a while, but by March 2014 the company had banished antibiotics from all 16 of its hatcheries.