The worm that turned (twice)

Foundry Cove on the Hudson River was one of the most heavily metal-polluted areas in the world. Between 1953 and 1979, a battery factory released approximately 53 tons of cadmium (Cd) and nickel hydride waste into the cove, resulting in sediment Cd concentrations as high as 10,000 ppm. The cove's commonest invertebrate, Limnodrilus hoffmeisteri, an oligochaete worm, evolved resistance to the Cd, and its central position in the food web is thought to promote the transfer of the metal through the ecosystem. In the August 4, PNAS Jeffrey S. Levinton and colleagues at Stony Brook University report that L. hoffmeisteri has subsequently lost its resistance following a major cleanup of the site in the mid-1990s (PNAS, DOI:10.1073/pnas.1731446100, August 4, 2003).

Levinton et al. measured the resistance of L. hoffmeisteri to Cd over a 9-year period (1993–2002) starting 1 year before the $100 million Superfund cleanup, which immediately...