Oyster Reef Restoration Benefits Farmers, Coastal Communities
Monday, June 5, 2023
By Lynn Fantom for Civil Eats.
Broadcast version by Kathryn Carley for New Hampshire News Connection reporting for the Solutions Journalism Network-Public News Service Collaboration
On a recent spring evening at Crave Fishbar in New York City, the oysters resting on beds of ice hailed from Long Island, Virginia, Washington, Cape Cod, and British Columbia. But once they’d been slurped, all of their shells went to a single place: New York Harbor.
As a participant in the Billion Oyster Project, Crave Fishbar is in its eighth year of collecting shells to help restore the oyster reefs in New York Harbor. The restaurant’s servers, who include many aspiring actors, tell the origin stories of the daily array of oyster options—the better the story, the greater the popularity of that brand, said Jeremy Benson, general manager of the Upper West Side location.
But the best story the team tells is that of the Billion Oyster Project, a nonprofit founded in 2014 that has organized 15,000 volunteers and 60 restaurants to restore oysters at 15 reef sites across New York’s five boroughs.
The effort seeks to bring back the harbor’s oyster population—which was destroyed by overharvesting and pollution in less than 100 years—by collecting used shells, installing them in critical locations, and “seeding” baby oysters on top to form reefs.
In addition to donating shells, Crave Fishbar employees have learned about the bivalve’s ability to clean the water and make shorelines more resilient to climate change. Every year, they join other volunteers who remove plastic forks from shell piles, clean cured shell, and load cages destined for the harbor, a body of water that The New York Times has described as “once an open sewer.”
“Now there are dolphins in the Bronx River. There are whales in New York Harbor. There are harbor seals underneath the Verrazano Bridge,” Benson told me during a recent visit, wrapping up his story with a happy ending also due in no small part to the Clean Water Act of 1972 and subsequent changes to wastewater handling.
When it comes to oyster reef restoration, the enthusiasm of the Crave Fishbar crew is not unusual, and that type of engagement is a driver of environmental activism that’s not to be underestimated.
“When the community is enthusiastic, the aquaculture community is enthusiastic, the conservation community is enthusiastic, then the regulators are sitting there saying, ‘Wow, this is great. Let’s go!’ So, this has been enormously powerful,” said Boze Hancock, senior marine habitat restoration scientist at The Nature Conservancy (TNC).
Though some oyster reef restoration projects, like those in the Chesapeake Bay, operate at unprecedented scale globally, others are small, community efforts. They have involved Rotary Club members, public school kids, nonprofits, community shellfish commissions, universities, federal, state, and local governments, even the lawyers who won the Deepwater Horizon oil settlement. (Baby oysters are now growing on some of the 33 reefs built along Florida’s Gulf Coast as a result of that payout.)
In addition to New York Harbor, Pew Charitable Trusts points to reef restoration efforts in the Chesapeake Bay, Florida, Louisiana, New Jersey, North Carolina, South Carolina, and Texas—and throughout the world.
With 20 years of momentum behind them, the people and groups undertaking these conservation projects have garnered both funding and expertise. But one thing that’s in short supply is the oyster shell itself. That scarcity has led to concerns about what to use instead, with disagreements playing out in heated meetings, court battles, and op-eds. And the challenges are often amplified because so many different players have a stake in restoration efforts.
“If you have five different people in a room, you’re going to have six opinions,” said Taylor Goelz, a marine scientist and senior program manager focused on the ocean and the climate for the Aspen Institute, who also hosts The Ocean Decade Show podcast. She was the lead author on a paper, “Alternative Substrates Used for Oyster Reef Restoration,” when she was a research associate at Virginia Institute of Marine Science. Although approaches may differ, Goelz said most people can agree on one thing: “They all want more oysters.”
Oysters are an incredibly carbon-, space-, and resource-efficient source of protein, which are really yummy,” said Hancock of TNC. “But they also provide ecosystem services.”
Like all bivalves, oysters are multitasking ecosystem engineers. They feed by filtering algae from the water—more than 50 gallons a day. That process removes excess nitrogen, which can create harmful algae blooms, and leaves cleaner water behind.
As they build their shells from calcium carbonate, oysters sequester carbon in a way that is cost effective and energy efficient. Clustered on reefs, they also help protect shorelines from erosion and storm surges. The reef itself provides shade and traps moisture during low tide, giving heat-stressed intertidal marine life a cool microhabitat that helps them adapt to rising temperatures.
The clearer water resulting from filter feeding also allows sunlight to penetrate and promote the growth of seagrass, “one of the other really important habitats that we are missing,” said Hancock. Ecosystem engineers themselves, seagrasses also clean the surrounding water and help take carbon dioxide out of the atmosphere, while sheltering a wide array of marine life.
Oyster reefs provide habitat for hundreds of species, a benefit TNC started to quantify as early as 2012. Mussels, barnacles, and sea anemones settle on reefs and provide food for many species. Crabs and fish also hide from predators in reef crevices. “These reefs pump out fish. It’s amazing,” added Hancock, who has worked in shellfish restoration in the U.S. since 2004.
The wallets of fishermen benefit—but so do community coffers. In Greenwich, Connecticut, for example, a National Oceanic and Atmospheric Administration (NOAA) fisheries study calculated that oysters provided the town with an annual financial benefit between $2.8 and $5.8 million. Without shellfish, the town would need to invest that much in wastewater treatment, septic system upgrades, and better storm water management.
Experts agree that the general public is increasingly aware of both these economic and environmental benefits. It’s one reason there has been such a boom in oyster reef restoration, Goelz said. Crave Fishbar’s Benson agreed. “In the restaurant, I have four or five in-depth conversations with people every week about oyster restoration,” he added.
Oyster Reef Restoration Also Spawns Controversy
Wild oysters grow by continually settling on top of other oysters or older shell, rocks, and piers and then reproducing. They fuse together, creating rock-like, three-dimensional structures. But overharvesting, pollution, disease, and dredging have destroyed more than 85 percent of oyster reefs globally. And now climate change poses an added threat.
The scale is enormous and because different locations have seen different arrays of impacts. But all successful reefs require two things: healthy oysters and strong foundations on which they can grow.
Generally, the reefs in the Southeast and Gulf of Mexico tend to have enough native oysters but not enough substrate for the babies to latch on to, Hancock explained. In other places, such as the West Coast and the northern portion of the East Coast, there are too few oysters left to settle a reef.
“So, the process of restoration has to step back to [first] provide the substrate and then add the breeding oysters to provide the larvae to settle on that substrate,” he said.
The go-to substrate for restoration projects has traditionally been recycled, fossilized, or dredged native oyster shell. Some Chesapeake Bay watermen, along with the Maryland Department of Marine Resources, still advocate for dredging shell deposits in one place and moving them to another, although the stance is controversial.
As one example of a shell recycling program, New York’s Billion Oyster Project has collected 2 million pounds of shell (1,000 tons) since 2014. Meanwhile, a Florida quarry produced 112,000 tons of fossilized shell—enough for just a single Maryland tributary restoration. (As a point of reference, the landmark Chesapeake Bay Program has plans to restore native oyster habitat and populations in 10 tributaries by 2025.)
For the scale of restoration needed, there is simply not enough shell. “Alternative substrates have to become part of the equation when you get down to it,” said Goelz.
For the last two decades, oyster restoration projects have tapped non-oyster shell, non-calcium stone (such as granite and sandstone), and limestone, as well as manufactured materials like porcelain and concrete. Which one works best is a matter of how well it matches the needs of an individual project, including which ecosystem services are sought.
If oysters will be harvested, experts say, alternative substrates should be layered with natural shell that doesn’t interfere with commonly used fishing methods like dredging or hand-tonging. Oysters growing on chunks of concrete, for example, can be too heavy for a hand-tonger to lift.
Stone such as granite has often successfully fostered oyster growth, but its use was questioned in 2021 during a major restoration project in Maryland when watermen contended that it might snag baited lines. (A county lawsuit and then a court injunction followed, which was only lifted in February.)
Varying public perceptions have also come into play with manufactured materials. For example, porcelain can be recycled from toilets and other bathroom fixtures, yet it has been eschewed as “potty-reef.”
Concrete can also be recycled from demolished buildings or bridges, and because it can be mounted vertically, it has performed as well as—or better than—natural oyster shell in supporting oyster growth and attracting other species to the ecosystem. But recycled concrete can contain toxic substances that leach when flooded with water. Although numerous studies have found it to be safe when it is prepared properly, skepticism remains, with new incidents fueling concerns.
Last September, for example, the Virginia Marine Resources Commission ordered removal of three reefs from the Lynnhaven River, a Chesapeake tributary in Virginia, after tests revealed the presence of harmful polyaromatic hydrocarbons in chunks of concrete and asphalt.
“I’m a great advocate of limestone” as an alternative substrate, said TNC’s Hancock. Limestone is calcium-based, like shells themselves. Plus, it can be built upward to avoid being buried in sediment over time.
“[We can get] barge loads of limestone and do it on a pretty big scale,” he added. “We’ve proved around the world that you could actually make a difference to the ecology fast enough. We’ve beaten up the planet so badly that we don’t have time to muck around.”
A New Market for Oysters
Krystin Ward farms oysters in Little Bay at the mouth of Great Bay Estuary in New Hampshire. She also works as a research technician at Jackson Estuarine Laboratory, where her projects include mapping oyster reefs and restoring them.
New Hampshire has only 18 miles of coastline, but Great Bay adds 144 more miles of shoreline. Ocean water travels 15 miles inland to reach Great Bay, where it then mixes with fresh water from seven rivers. It bears the distinction of being one of the nation’s most inland estuaries, and it’s a treasured habitat for Ward. “It can feel like a little hidden jewel,” she said.
Like some other oyster farmers, Ward found that a number of perfectly healthy oysters weren’t making it to market because they had grown too large for diners’ tastes. “You’re cleaning bags, you’re raking ‘em up from the bottom. And then there are some places you just overlook or you can’t get to one year,” Ward explained.
She began wondering: “What can we do with these? How can we still get a decent price?”
The Nature Conservancy helped answer that question. In 2019, its team worked with Ward and a few other farmers to study whether larger, older oysters could be substituted for the baby oysters (or “spat on shell” grown in nurseries) that are customary in restoration projects. The pilot study found that, one year later, 70 percent had survived. It was an “overwhelming success” and well-timed, with results coming in just as the pandemic was shuttering restaurants, leaving farmers with no market.
In 2020, TNC launched a broader program named SOAR—Supporting Oyster Aquaculture and Restoration—in partnership with The Pew Charitable Trusts, NOAA, and the U.S. Department of Agriculture.
n two years, the program purchased more than 3.5 million live oysters and brought them to 25 sites to restore 40 acres of oyster reef. At the same time, it supported 125 shellfish companies and preserved more than 450 jobs, according to TNC.
In February, TNC and Pew announced the second phase of SOAR, with funding of $6.3 million from the National Fish and Wildlife Foundation and Builders Vision. Later this year, growers who want to participate can apply to the program, which has set a goal of buying 2.5 million oysters and planting them at 12 restoration sites along the East and West Coasts.
“[Growers] are really excited about being able to provide an environmental benefit while they’re at it,” said Hancock. “We’ve even had growers who have said, ‘If all I do is produce oysters for restoration, that’ll be great.’”
What About Cost?
Scientists like Hancock are working on quantifying the benefits that people get from oyster reefs and asking big questions about whether the cost and effort are worth it.
In 2013, fisherman-journalist Bob Melamud was wondering much the same thing as he took the boat with a reef construction crew to the site of the world’s largest oyster restoration project on Maryland’s Harris Creek, a Chesapeake Bay tributary. Project managers were in the process of importing some $6.3 million worth of fossilized oyster shell from Florida because there wasn’t enough in Maryland.
“It takes a lot of work to build a reef. What I want to know is: will it work? And you should want to know, too. After all, you and I are paying for it,” Melamud wrote in Bay Weekly.
Altogether, with more than 200,000 cubic meters of substrate and over two billion oyster spat on shell, the project cost $52 million. But after just three years, comprehensive monitoring has already demonstrated a return on investment of $23 million annually through a robust increase in fishing revenues alone. “And there’s $11 million worth of blue crab produced by those reefs,” added Hancock. A model developed by the Virginia Institute of Marine Science also found that the oysters contribute more than $3 million a year in water purification services.
And all because they filtered the full volume of Harris Creek—350 acres, an area bigger than the National Mall—in less than 10 days in the summer. “It’s not just a bunch of tree-hugging greenies that wanna put these habitats back,” Hancock said.
Oysters: On a Reef or in a Cage
In Connectictut, where a law regulating oyster harvests appeared in the early 1700s, there hasn’t been the depletion of shellfish seen in the Chesapeake. Another difference: Connecticut has a growing aquaculture industry that values natural beds as a source of seed for its farming.
But extreme weather has been a problem. “Loads of sediment come down the rivers and then pile up on the beds, smothering adult or newly settled oysters,” said Tessa Getchis of the Connecticut Sea Grant and University of Connecticut Extension Program.
Last year the state began implementing a plan to restore and expand shellfish populations, and a 2021 law expanded Connecticut’s ability to acquire oyster shells for that purpose. It authorized the Commissioner of Agriculture to tap into federal, state, and private funding to support an oyster shell recycling program and conduct restoration. It also classified aquaculture as “farmland,” bestowing on shellfish growers key tax benefits.
As Boze Hancock said, “Oysters have those same [ecosystem] services, whether they’re in a cage or on a reef.”
Now, various shell recycling efforts—run by a private farm, town shellfish commissions, and university researchers—have been launched and a “state shell recycling coordinator” hired.
At restaurants, oyster festivals, and raw bars, “we’re seeing volumes of shell just thrown away,” said Getchis. But she knows that trend won’t be easy to reverse. “It takes a lot of work on the part of the restaurant,” ranging from training staff to sort out the shell to isolating it to avoid cross-contamination and rodent infestations. “While we’re optimistic, we’re trying to learn as much as we can now,” she said.
Undeterred, she added, “We want to keep the shell out of driveways and construction sites and incinerators. We want it in the water.”
Lynn Fantom wrote this article for Civil Eats.
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