Pity the snow geese that settled on lake berkeley as a stopover one stormy night in November 1995. The vast lake, covering almost 700 acres of a former open-pit copper mine in Butte, Montana, holds some 30 billion gallons of highly acidic, metal-laden water— scarcely a suitable refuge for migrating birds stalled by harsh weather. So when the flock rose up and turned southward the following morning, almost 350 carcasses were left behind. Autopsies showed their insides were lined with burns and festering sores from exposure to high concentrations of copper, cadmium, and arsenic.
Today one need only stand on the viewing platform and look at the pit— the lifeless yellow and gray walls that stretch for a mile in one direction and a mile and a half in the other and the dark, eerily placid lake— to see that it's hostile toward living things. Surely nothing could survive these perilous waters. But in 1995, the same year the birds died, a chemist studying lake composition retrieved some rope coated with brilliant green slime and took it to his colleagues at Montana Tech of the University of Montana, an institution locals proudly call the Tech. Having evolved in partnership with one of the world's richest and longest-running mining districts, it remains a world-class engineering and mining school. Grant Mitman, one of just three full-time biologists on the faculty, quickly identified the slime as a robust sample of single-celled algae known as Euglena mutabilis. Life had somehow established an outpost in the liquid barren that is the Berkeley Pit.
For Mitman, finding Euglena proved uncannily fortunate. At Dalhousie University in Halifax, Nova Scotia, where he received his doctorate, his passion was algae. "I trained all my life to be a marine biologist," he says, noting the irony in then having taken a post at an engineering school in the Rocky Mountains. Just as a landlocked, man-made toxic lake has reunited this scientist and his favorite subject, so too has it galvanized the long-standing interest of chemists Don and Andrea Stierle, a husband-and-wife team who also work at the university. The Stierles have spent their lives searching for naturally occurring compounds that can be used in agriculture and medicine. For them, the menagerie of small organisms— more than 40— discovered in Lake Berkeley during the past five years holds much potential.