 They're also good at cleaning up. An adult can filter 50 gallons of water per day. Oysters are a keystone species, so they're kind of like the building block of the estuarine food web. The Billion Oyster Project hopes to live up to its name by 2035. This winter, the Hudson River Park Trust will release the results of its third year of monitoring. Scientists will use the data to create more effective strategies for restoration and hopefully speed up the process.