(Paul Greenberg 16 Aug 2017; Photo Greg Kahn)
A biologist traced mercury from a company spill to contamination in songbirds, and devised a new way to hold polluters financially accountable.
It was just another sweltering summer afternoon gathering blood samples from Shenandoah Valley birds when the news came in. The ornithologist Dan Cristol had been conducting a preliminary assessment funded by DuPont to determine to what degree the company’s pollution of the watershed might have affected the avian community. DuPont was facing potential legal action and had cautiously agreed to one summer of funding for a small team to gauge just how expensive fixing the damages might be. True to his nature, Cristol hadn’t been tentative in his research. He and his students had skulked into stream-bank kingfisher nests, cornered screech owls near bridges, and mist-netted dozens of species of songbirds. Using tiny needles, they’d extracted drops of bird blood before gently releasing their subjects back into the wild. Then they’d shipped their samples to a toxicology lab at Texas A&M, and watched as their funding dribbled away at a rate of $55 per analyzed sample.
Now as the sun blazed over the South River, a major tributary of the mighty Shenandoah, and waves of heat rose up from the newly mown hayfields, Cristol opened an email from the lab and read the first test results.
“Holy fucking shit,” one of the students cried out.
“I rechecked the numbers about five times to make sure,” Cristol recalls. “We were being funded by the responsible party, so I figured DuPont would look at what we’d found and say, ‘OK, thanks but no thanks, we’ve seen enough.’ I was worried that after this tantalizing glimpse we would not get to learn what was really going on. But to their credit, everyone just kept moving forward and letting us propose to answer each new question that arose.”
Cristol and his students had discovered that the DuPont mercury spill had penetrated much further into the avian food web than anyone had previously expected. Not only was mercury found in fish-eating raptors like osprey and eagles, but it was present in bluebirds that flitted far away from the contaminated South River; it was in surprisingly high levels in the feathers of the distinctly non-riverine Red-eyed Vireo whose song tells you to look-up way-up tree-top to find it; it was in scrappy Carolina Wrens, whirling Tree Swallows, and reclusive thrushes. Even in the diminutive Blue-gray Gnatcatcher that weighs in at a miniscule third of an ounce.
More importantly, the work had laid the foundation for a novel way to restore North American songbird populations that are declining throughout the country. For Cristol’s research has ultimately perfected a way of holding major polluters accountable for something as profound as it has long been intangible: a means to calculate and seek reparations for bird years lost.
“You couldn’t have a better site to test the effects of methylmercury,” Cristol told me as we stood on a bridge over the South River in the City of Waynesboro and stared southeast at a 177-acre chemical plant. For roughly 50 years this gray smudge of a facility, built into the green hillsides by DuPont in 1928, manufactured something called acetate fibers—which used mercury as a catalyst for the first 20 years of its operation.
DuPont to its credit has never strongly contested that it put significant amounts of mercury into the South River. Ever since mercury was detected in river sediment and floodplain soil around the plant in the 1970s, the corporation has been trying to figure out a way to put its pollution legacy behind it. For years DuPont funded a vaguely missioned “South River Science Team” where state officials and academics monitored mercury levels in fish, with the hope that concentrations would eventually go down. No such decrease was observed. Sampling continued to show levels in some fish higher than 4 parts per million—nearly four times that found in swordfish, which the FDA urges consumers to avoid because of high mercury levels. Nevertheless, officials representing the State of Virginia (technically the key plaintiff in these early proceedings) seemed at a loss as to what to do next.
“They had been completely bamboozled,” says Nancy Marks, a senior attorney for the nonprofit Natural Resources Defense Council’s litigation team. Under Marks’s direction NRDC filed an intention to sue DuPont in the early 2000s to move the issue forward from monitoring to mitigation. “[DuPont’s] remedy was to have a hundred year monitoring program. But we knew the mercury in the river was sky high. And DuPont was the only obvious source.” Unlike other American watersheds that have been host to numerous polluters, the Waynesboro DuPont plant is all the mercury-discharging industry the South River basin ever had. The bulk of the mercury in the ecosystem and any harm it may have caused birds is undeniably DuPont’s fault.