Marine scientists, planners and government officials say millions of mollusks planted in waters off New York and other cities could go a long way toward cleaning up America’s polluted urban environment. The oyster and other shellfish can slurp up toxins and eliminate decades of dirt.

Landscape architect Kate Orff has a name for the work she does at her Scape firm: Oyster-tecture. Orff is designing a park and a living reef for the mouth of Brooklyn’s Gowanus Canal, where oysters could take hold and help filter one of the nation’s most polluted waterways. “My new hero is the oyster, with its biological power,” Orff says. Oyster-tecture is a 21st-century approach to creating new waterfront infrastructures where long-gone shellfish can be brought back.