California released 37 orphaned sea otters into a bay scientists had already written off as dead — a desperate experiment that few believed could work. For fifteen years, the marine ecosystem showed no obvious signs of recovery, and experts quietly assumed the otters had vanished.
In 2001, biologists in California took 37 orphaned sea otter pups that had been found sick or stranded along the coast and released them into Elkhorn Slough, an estuary about 20 miles north of Monterey Bay. At the time, the site was in poor condition: more than half of its marshland had eroded since the 1950s, algae blooms were choking the eelgrass, and burrowing shore crabs were destabilizing the…