‘Billion Oyster Project’ Works to Replace Reefs

illion Oyster Project is working to engage 1 million New Yorkers in an ambitious goal: to re-establish oyster reefs in New York Harbor. The nonprofit aims to introduce 1 billion oysters by 2035, enough to filter all the water in the harbor every three days. Thus far, Billion Oyster Project has returned 122 million oysters to New York City’s waters. It plans to add another 84 million this year.

There were once 220,000 acres of oyster reefs in New York Harbor, long before it was the industrial waterway it is today. The nonprofit hopes to re-establish enough oyster reefs in the harbor to serve as surf breaks for coastal New York City neighborhoods, absorbing waves and preventing erosion.

The restoration will attract more wildlife back to the city’s shores. Biologists refer to oysters as a keystone species because they create habitats for other critters, underpinning the health of an ecosystem. Billion Oyster Project has already observed a wealth of biodiversity in its oyster reefs, including mud crabs, oyster toadfish, sea robins, and even seahorses.

The nonprofit will have reached its goal when the oyster population is healthy enough to reproduce and survive on its own. “It’s all a big experiment,” says Charlotte Boesch, program manager for shell collection at the nonprofit.

Oyster larvae settle on hard substances, such as shells, to form the foundations of oyster reefs, but that substrate no longer naturally occurs in New York Harbor. “It’s basically just muck and mud,” Boesch says. “We really have to get the substrate elsewhere, so we get it from restaurants.”

The nonprofit collects oyster, clam, and scallop shells from New York City restaurants and deposits them in massive outdoor piles where exposure to insects and the elements cleans them. After a year outdoors, the shells go back into the harbor as substrate.

Some of the oyster reefs the nonprofit installs are extensive, requiring barges, cranes, and specialized contractors. A reef in Jamaica Bay — visible from Terminal 4 at JFK Airport — is one such project, established in 2016 with 40,000 oysters. The group introduced 15 million more oysters to that reef in 2023 and plans to add another 5 million this year.

Steven DeWitt/Witness Tree Media

Other installations are smaller, aimed more at education than repopulation. These field stations are often built by volunteers who wade into the harbor to deposit bags of oysters, as seen here.

The nonprofit has a close relationship with the Urban Assembly New York Harbor School, a public high school on Governors Island, just 400 yards from the Brooklyn waterfront. The school’s former director and aquaculture teacher founded Billion Oyster Project, and the organization operates out of its building. Students help install and monitor reefs, including by scuba diving to inspect them.

The nonprofit has developed a curriculum for local teachers and installed research cages along city piers, where students can interact with oysters and the species they host. City students who learn about their local waterways on field trips and in their classrooms, Boesch says, will someday be advocates for and stewards of a restored New York Harbor.