Environment
Flash flooding in New York City. Sinking coasts in Louisiana. To guard against the effects of climate change, these communities are turning to bivalves.
ByKathleen Rellihan
Published October 20, 2023
• 6 min read
This year has been a year of record-breaking weather. The summer of 2023 was the hottest in history followed by September being the warmest on record by a wide margin. In New York, it was also the wettest September in over a century. Last month, torrential downpours from Tropical Storm Ophelia caused flash flooding in New York City with almost eight inches of rain falling in some areas, wreaking havoc throughout the city. A sea lion at the Central Park Zoo even was briefly able to swim out of her pool enclosure.
The summer storm wasn’t the first time the city confronted the danger of rising seas and climate-intensified storms. Twelve years ago, Superstorm Sandy flooded Staten Island. But in the wake of the destruction a visionary idea took hold—to use nature as a storm barrier.
Deep in coastal harbors and waterways, an unlikely ally has been hiding all long: oysters. These keystone species have many superpowers—including helping to protect shorelines from storm surge and high tides and reduce the impacts of erosion from intense rain.
Oyster restoration as a climate adaptation is taking seed globally, from China to Australia. In the U.S, New York and Louisiana are two places where oysters have been deeply woven into the culture and economy for centuries, but now these communities are looking to these vital creatures to help protect their vulnerable coastlines.
New York and its Billion Oyster idea
New York City was once the oyster capital of the world; the bivalves were so abundant in the 19th century they were sold from street carts, like hot dogs and halal food are today. After a century of over harvesting and pollution, the city’s oysters reefs—once numbering 220,000—nearly disappeared entirely from New York Harbor, one of the world’s largest natural harbors.
Now, the city’s Billion Oyster Project is reintroducing 100 million oysters per year in the harbor, and with the help of students, volunteers, and local communities, the non-profit plans to restore one billion oysters by 2035.
An adult oyster can filter up to 50 gallons of water a day; one billion can filter the entire harbor in three days. Oysters also sequester carbon in a way that’s cost-effective and energy efficient, helping fight the climate change contributing to these destructive floods.
The city’s bivalves are also being used in another coastal resiliency project, Living Breakwaters, to shore up the disappearing coastline of Staten Island. In partnership with Billion Oyster Project, the project is building half-mile-long partially submerged breakwaters, strategically covered in recycled oyster reefs that will mitigate flooding and erosion while providing new habitat for hundreds of marine species.
Living Breakwaters is the brainchild of landscape architect and SCAPE founder Kate Orff, who was inspired during the aftermath of Hurricane Sandy’s disastrous flooding to come up with a green infrastructure solution. The architect says rebuilding the city’s once-plentiful oyster reefs is just one way nature restoration can protect the populous region.
“The biggest fix is knitting all of the pieces of landscape, from upland forest to the coastal reefs, back together and making safer places for the water to go,” says Orff.
What makes Living Breakwaters and Billion Oyster Project so effective as a long-term nature-based climate adaptation is that the projects are also training the next stewards of our waterways.
The Billion Oyster Project trains students at New York Harbor School, a public highschool on Governors Island, for maritime careers and works with over 100 other schools across New York City, including schools on Staten Island near the site of Living Breakwaters.
“It involves students deeply in their own environment so they can reconnect to the water and understand their own climate risk,” says Orrff about the curriculum.
The landscape architect met the co-founders of Billion Oyster Project as board members of New York Harbor School in 2009. After Superstorm Sandy hit in 2012, both projects scaled up their operations and collaboration, shares Orff.
Protecting Louisiana’s sinking coasts and cultural heritage
More than a thousand miles south, another coast has turned to oysters for a helping hand.
“Louisiana has been on the forefront of climate change,” says Devyani Kar, PhD, a coastal resilience scientist based in Baton Rouge who’s led local climate adaptation and resilience projects. “And now [the state] is taking a lead in looking for localized solutions to adapt to climate change,” she says.
Oysters in Louisiana, like New York, have been part of the state’s agricultural and culinary culture for centuries. Already, Louisiana produces almost a third of the oysters commercially grown in the U.S., but restoring populations to their historic levels could help protect the state’s eroding shoreline.
Kar is a board member of the Coalition to Restore Coastal Louisiana, one of the largest oyster recycling programs in the nation. Similar to the Billion Oyster Project, shells that would otherwise end up in a landfill are collected from New Orleans restaurants and public drop-off sites and used to rebuild oyster reefs and shoreline habitat across coastal Louisiana.
With the help of volunteers and local communities, the coalition has built over 8,000 feet of living shoreline with 13 million pounds of oyster shells. This living shoreline not only reduces erosion by as much as 50 percent, but it also helps preserve disappearing cultural heritage sites.
The program works with the Pointe-au-Chien Indian Tribe to select centuries-old earthen mounds built by the tribe’s ancestors. Oyster reefs can help protect these historic sites from rising seas and coastal erosion. The Terrebonne Basin, a low-lying delta on Louisiana’s coast, is one of the fastest eroding areas in the U.S.
Just one piece of the puzzle
Near the southern tip of Florida, marine temperatures exceeded 100 degrees in July, in what could be the hottest seawater temperature ever recorded.
“There’s no living thing, except jellyfish, that can survive the temperatures that we’ve seen in the Gulf,” warns Orff. “Marine heat waves like we experienced in 2023 threaten the entire web of ocean life. “
That means these living reefs are threatened by the warming planet they’re helping us adapt to.
“Oysters are not a quick fix,” stresses Orff. “We can’t pretend like it’s the past; we’ve changed our water temperature. We’ve changed water quality and the water chemistry.”
And while oyster reef restoration projects won’t stop seas from rising or prevent a hotter atmosphere from unleashing torrential downpours, they’re one solution that comes with a number of environmental and economic benefits.
“If we are able to reduce carbon emissions and water pollution and maintain a livable window for global temperatures,” says Orff, “then oysters can play a huge role helping mitigate the impacts of coastal change.”
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Copyright for syndicated content belongs to the linked Source : National Geographic – https://www.nationalgeographic.com/environment/article/billion-oyster-reef-restoration-floods-climate-change