Troubled Waters
By Peter Andrey Smith, The Walrus (July/August, 2013)
One chilly October morning, Beth Cheever hopped out of an aluminum boat. In rubber boots, a life jacket, and a knit hat pulled down over her ears, she walked the portage trail, beneath denuded alders and paper birches damp with the previous night’s rain, to the granite shoreline. She had never poisoned a lake before. Yet the thirty-two-year-old ecologist from New Hampshire had driven her Dodge Caravan twenty-two hours from Trent University in Peterborough, Ontario, to this corner of northwestern Ontario, just thirty minutes from the Manitoba border, with a plan to do just that. Spruces guarded the glassine pool’s edges like stoic sentries, and signs posted all around told wayward anglers to keep their lines out of the water. Lake 221 contained the beginnings of an experiment, a study of what could go wrong when the team laced an entire lake with antimicrobial compounds—deliberately, with the utmost precision.
Nanosilver kills microbial life, and, as the “nano-” in its name suggests, the antibacterial battle takes place in minutiae, each particle so small that a million of them could fit on the period at the end of this sentence. Nanoparticles have applications in technology, medicine, and agriculture. As Cheever’s post-doctoral supervisor, Maggie Xenopoulos, an aquatic biologist at Trent, said to me earlier, “They’re the future, and yet we have no idea if they’re affecting our environment.” In one laboratory study, scientists found cranio-facial deformities in minnows exposed as embryos to high concentrations for ninety-six hours. But lab studies only show so much; a beaker or bottle experiment does not necessarily reflect the complexities of an entire lake. If nanosilver killed off too many species or a key component in the web of life, the whole ecosystem might malfunction and collapse. To learn what happens in situ, Cheever’s team intended to spend two years sending an infinitesimal galaxy of particles into the lake.
Lake 221 lies within the bounds of the Experimental Lakes Area, a field site familiar to readers of the Proceedings of the National Academy of Sciences, Limnology and Oceanography and the Journal of Plankton Research. Since 1968, fifty-eight freshwater basins contained by 200 square kilometres of granite and boreal forest have functioned as real-world test tubes, untouched by human hands except by scientific design. Lakes 226 and 227 demonstrated that phosphorus led to algal pollution, which convinced politicians to mandate the reformulation of detergents. Sulphuric acid caused a dramatic shift in species in Lake 223, bringing about international emissions limits to address acid rain. Long-term data has shown the lakes to be early warning sentinels for climate change. More recently, in an experiment on Lake 658, scientists demonstrated how mercury accumulated in fish; and on Lake 260, scientist Karen Kidd identified a single chemical, the synthetic estrogen in birth control pills, as the cause of mass feminization in male fish and a cataclysmic population crash. Anywhere else, such massive die-offs might have resulted from confounding factors: human activity, industrial effluent, or any number of synthetic organic compounds found in pharmaceuticals and personal care products. But the studies at the lake pinpointed cause and effect more decisively. They have drawn generations of scientists and students to the boreal shield, like pilgrims to the holy waters of ecological research. Cheever made her first pilgrimage in 2012.
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