Bringing Back Oysters

In New York City, students from Middle School 50 (MS 50) gather at a park overlooking the waters that flow into New York Harbor. These sixth-graders aren’t gazing at passing boats or the Manhattan skyline. Instead, they’re concerned with what’s happening beneath the water’s surface.

A student pulls a rope hanging over the park’s railing, hoisting up a cage that had been submerged in the harbor. Inside, young oysters are growing. The students use adjustable tools called calipers to measure the growth of the mollusks. These animals’ soft bodies are protected inside closed shells.

In New York City, students from Middle School 50 (MS 50) gather at a park. They look out over the waters flowing into New York Harbor. These sixth-graders aren’t looking at passing boats or the Manhattan skyline. Instead, they’re concerned with what’s happening under the water.

A rope hangs over the park’s railing. It’s attached to an underwater cage. A student grabs the rope and pulls up the cage. Inside, young oysters are growing. The students use adjustable tools called calipers to measure the growth of the mollusks. These animals have soft bodies inside closed shells.

Oysters live in shallow waters around the world. In the wild, the animals grow on top of one another to form reefs. Hundreds of years ago, oyster reefs covered 890 square kilometers (340 square miles) of New York Harbor. That’s a little larger than New York City itself! But now, these reefs have all but vanished. That’s why students from MS 50 and many other local schools have joined forces with thousands of volunteers across the city as part of the Billion Oyster Project (BOP). They aim to restore a billion of the mollusks to New York Harbor by 2035.

Oysters are a keystone species. That means they’re vital to their ecosystem—a community of organisms interacting with their nonliving environment. Oyster reefs provide homes for other creatures, protect coastlines, and keep waters clean. “When I first saw an oyster, I thought, ‘This is just a shell. What can this do?’” says Helen Espinal, a sixth-grader at MS 50. “And then the more you learn about it, the more you see how much power this little animal has.”

Oysters live in shallow waters around the world. The animals grow on top of one another in the wild. That’s how they form reefs. Hundreds of years ago, oyster reefs covered 890 square kilometers (340 square miles) of New York Harbor. That’s a little larger than New York City itself! But now, these reefs have almost disappeared. So students from MS 50 and many other local schools have joined thousands of volunteers across the city. They’re working with the Billion Oyster Project (BOP). They hope to restore a billion of the mollusks to New York Harbor by 2035.

Oysters are a keystone species. They’re important to their ecosystem. That’s a community of living things with their nonliving environment. Oyster reefs provide homes for other creatures. They also protect coastlines and keep waters clean. “When I first saw an oyster, I thought, ‘This is just a shell. What can this do?’” says Helen Espinal. She’s a sixth-grader at MS 50. “And then the more you learn about it, the more you see how much power this little animal has.”

Today, oysters are considered a delicacy. But the shellfish were once so common in New York City that even street carts served them. Over time, pollution, overharvesting, and habitat loss decimated the oyster population. Oysters around the world are facing a similar fate. According to The Nature Conservancy, 85 percent of the world’s oyster reefs have disappeared. “That makes them one of the most imperiled habitats on our planet,” says Peter Kingsley-Smith. He’s a marine scientist at the South Carolina Department of Natural Resources.

The loss of oysters is bad news for other animals as well. “The diversity of other organisms that call oyster reefs home is truly remarkable,” says Kingsley-Smith. “All of the nooks and crannies in an oyster reef provide potential habitats for fish, crabs, sponges, and all sorts of other fascinating creatures.”

Oyster reefs help people, too. They protect shorelines by acting as a buffer against storm surges, which occur when rising water is pushed onto land, causing flooding. The reefs help reduce erosion by blocking waves that can wash away sand and soil. Oysters also help keep harbors clean. These filter feeders pump water through their bodies, filtering out algae and bacteria to eat (see Inside an Oyster, below). In the process, they remove pollution from the water. “A single adult oyster can filter up to [190 liters] 50 gallons of water in a day,” says MS 50 sixth-grader Rose Beidel.

Today, oysters are expensive. But the shellfish used to be very common in New York City. Even street carts served them. Over time, the oysters disappeared. Pollution, overharvesting, and habitat loss destroyed them. Oysters around the world face the same problems. The Nature Conservancy reports that 85 percent of the world’s oyster reefs are gone. “That makes them one of the most imperiled habitats on our planet,” says Peter Kingsley-Smith. He’s a marine scientist at the South Carolina Department of Natural Resources.

The loss of oysters is also bad news for other animals. “The diversity of other organisms that call oyster reefs home is truly remarkable,” says Kingsley-Smith. “All of the nooks and crannies in an oyster reef provide potential habitats for fish, crabs, sponges, and all sorts of other fascinating creatures.”

Oyster reefs help people too. They protect shorelines. When rising water is pushed onto land, it causes flooding. But oyster reefs are a buffer against these storm surges. The reefs also help reduce erosion. They block waves that can wash away sand and soil. And oysters help keep harbors clean. These filter feeders pump water through their bodies. They filter out algae and bacteria to eat (see Inside an Oyster). As this happens, they remove pollution from the water. “A single adult oyster can filter up to [190 liters] 50 gallons of water in a day,” says MS 50 sixth-grader Rose Beidel.

Restoring New York’s oyster reefs is a team effort. High school students at the New York Harbor School help breed the oysters. “They take adult oysters and put them in a special tank, and they slowly change the temperature of the tank to mimic spring,” explains Ann Fraioli. She’s BOP’s director of education. Warmer water triggers the oysters to reproduce. The tiny, immature oyster larvae have shells smaller than the period at the end of this sentence.

Teamwork is needed to restore New York’s oyster reefs. High school students at the New York Harbor School help breed the oysters. “They take adult oysters and put them in a special tank, and they slowly change the temperature of the tank to mimic spring,” explains Ann Fraioli. She’s BOP’s director of education. Warmer water causes the oysters to reproduce. The baby oysters are called larvae. They have shells smaller than the period at the end of this sentence.

Meanwhile, BOP collects empty oyster shells from New York City restaurants. The shells are left outside for more than a year, exposed to the sun and insects to clean the shells and get rid of germs. Students and volunteers scoop the clean shells into mesh bags and lower them into the tank filled with oyster larvae. The larvae attach to the empty shells. Now, these young mollusks are ready to form reefs. BOP staff place the mesh bags in different spots on the floor of the harbor (see Oyster Reefs). There, the oysters will hopefully continue to grow.

Meanwhile, BOP collects empty oyster shells from New York City restaurants. The shells are left outside for more than a year. The sun and insects clean the shells and get rid of germs. Students and volunteers scoop the clean shells into mesh bags. Then they place the shells in the tank of oyster larvae. The larvae attach to the empty shells. Now these young mollusks can form reefs. BOP staff places the mesh bags in different spots on the harbor floor (see Oyster Reefs). Hopefully, the oysters will continue to grow there.

Some reef sites, like the one MS 50 students monitor, sit close to shore. Each of these reefs is about the size of a microwave oven. Project helpers wade farther out in the water to check on reefs the size of filing cabinets. And high school students dive to make observations of even larger, deeper reefs.

Some reef sites sit close to shore. The MS 50 students check on one of these. Each of these reefs is about the size of a microwave oven. Reefs the size of filing cabinets are farther out in the water. Project helpers wade to check on those. And high school students dive to observe even larger, deeper reefs.

These volunteers keep tabs on the young oysters’ growth and survival rate. Although the harbor is cleaner than it once was, pollution remains a problem. “Sometimes, the oysters die,” says Caden Koffi, a sixth-grade student at MS 50. Then there’s just one thing to do, he says: “Figure out what happened, find ways to improve, and start again.”

So far, BOP has restored 75 million oysters to New York Harbor. But for the project to really succeed, oysters will need to reproduce there naturally. “And we’re already seeing that,” says Fraioli of BOP. Volunteers have spotted new oysters growing on the reefs and nearby rocks. Fish, crabs, sponges, and other creatures are making homes on and around the new structures. “As soon as you put anything down there, it’s amazing what flocks to it,” she says.

The students are happy that their efforts are improving the waters around their home for marine creatures and people alike. “We actually get to help make our environment better than it was before,” says MS 50 sixth-grader Camila Jimenez.

These volunteers record the young oysters’ growth and survival rate. The harbor is cleaner than it used to be. But pollution is still a problem. “Sometimes, the oysters die,” says Caden Koffi. He’s a sixth-grade student at MS 50. Then there’s just one thing to do, he says. “Figure out what happened, find ways to improve, and start again.”

So far, BOP has restored 75 million oysters to New York Harbor. But oysters will need to reproduce there naturally. That’s the only way the project can succeed. “And we’re already seeing that,” says Fraioli of BOP. New oysters are growing on the reefs and nearby rocks. Volunteers are seeing fish, crabs, sponges, and other creatures. These animals are making homes on and around the new reefs. “As soon as you put anything down there, it’s amazing what flocks to it,” she says.

The students are happy to see the results. Their work is improving the waters around their home for marine creatures and for people. “We actually get to help make our environment better than it was before,” says MS 50 sixth-grader Camila Jimenez.