The other week, I read about New York’s Billion Oysters project, which collects used oyster shells from 45 city restaurants with the goal of building a reef that will calm big waves, help prevent coastal flooding, and ease erosion. Since the project started in 2014, they’ve collected 1.8 million pounds, which are cleaned, cured in the sun and “set” with microscopic larvae. The bags of old shells are placed around city waters and will become home for baby oysters, as well as eventually creating a reef. It’s a project that has attracted a lot of media attention, in part because there are so many ways ordinary people can help.