In 1609, when explorer Henry Hudson started to sail up the great river that would later bear his name, he and his crew were visited by four canoes full of Native Americans who brought a “very great store of very good oysters aboard.”

The oyster restoration program director for New York-New Jersey Baykeeper, Meredith Comi, can imagine the oyster population in the estuary at the time of Hudson’s explorations.

“When he arrived, I have a picture in my mind of oyster reefs everywhere,” she says. “Not only subtidal, where people didn’t see, but also all along the coasts, so that they were extremely plentiful.”

Unfortunately, there are no longer any oyster reefs, which are densely packed underwater communities of oysters, left within the Hudson-Raritan Estuary. The Hudson-Raritan Estuary is a system of bays and tidal rivers where the Hudson, Hackensack, Passaic, Rahway and Raritan rivers meet the Atlantic Ocean. The New York/New Jersey Baykeeper’s oyster restoration program is attempting to refill the estuary with a vibrant population of oysters.

“The oysters that are still around, there’s not enough of them to produce a critical mass of larvae [baby oysters] to repopulate anything, so . . . we kind of have to start all the way at the beginning and purchase larvae from other labs, actually, and jump-start the whole reef process,” Comi says.

Comi says that several factors have contributed to the demise of oyster reefs in the region. One factor is humanity’s voracious appetite for the species during the late 1800s and early 1900s. Another factor is that people were keeping the oyster shells for chicken feed or to construct buildings, rather than returning them to the water. Oyster larvae need the shells to develop.

The Hudson-Raritan Estuary was also frequently polluted by sewage spills as it developed into the busiest harbor in the world. Though oysters are resilient creatures, the mollusks started to become contaminated with diseases like cholera and typhoid at the end of the 19th century. When humans began to get sick from dining on these contaminated oysters, harvesting on the Hudson-Raritan Estuary’s oyster beds began to be shut down.

New York-New Jersey Baykeeper

Since 1999, New York/New Jersey Baykeeper, an organization seeking to restore and protect the Hudson-Raritan Estuary, has been working on restoring oyster beds to the region. The restoration effort allows for individuals and groups to join the organization’s oyster gardening program.

After attending a mandatory two-hour training session, participants are sent out with an oyster float. An oyster float is basically a bag held up in the water by two pontoons, or floating supports, and 500 to 1,000 baby oysters. Participants observe the oysters’ growth for about a year, before being given the opportunity to plant their oysters on the reefs that the organization is attempting to rebuild.

Comi says that many of New York-New Jersey Baykeeper’s oyster gardeners are middle school and high school students. “They really become invested and attached to the waters here, and what’s in it,” she says. “It’s been really taking off as a learning tool, an education tool.”

The oyster restoration program director believes that oysters are a keystone species, or a species that is critical to the structure of an entire ecological community.

“This is one species that in the food web of the estuary really structures that whole food web,” she says. “If you remove the oyster, a lot of other food chains are going to collapse because the oyster reefs provide a lot of that habitat.”

Comi says that the animals and plants that congregate around oyster reefs include worms, crabs, algae, mussels, flounder, black drum, and bass. At two sites where Baykeeper is creating oyster reefs—in New Jersey’s Navesink River and Keyport Harbor—some of these species are returning to the area.

“Even just adding shells increased the habitat a little bit,” Comi says. “A lot of anemones and things were then there.”

Besides having oyster reefs become habitat for other organisms, oysters are prized for their impressive filtering abilities. Oysters feed by sucking in water, extracting algae and other nutrient particles, and then releasing cleaner water. An adult oyster can filter as much as 50 gallons of water a day. This benefits the estuary by getting rid of algae, improving water clarity, and halting waterways from being overcome by sediment.

Comi says that having a healthy oyster population in the Hudson-Raritan Estuary is in line with New York-New Jersey Baykeeper’s attempts to restore the Hudson-Raritan Estuary habitat. “Our goals are simple,” she says. “We want improved water quality here. As oysters filter, it cleans the water.”