Oysters are breathing life into the Chesapeake Bay
Ben Seal for Reasons to be Cheerful
Oysters are breathing life into the Chesapeake Bay
It would be a quiet and peaceful morning at the edge of the Choptank River in Cambridge, Maryland, if not for the forklifts racing around the pier, scraping 5-foot-tall metal cages along the ground as they go. It’s early May and the sun is just beginning to burn off the mid-morning haze, but the crew has been at it since dawn. Everyone is energized despite the early start, and rightfully so, because the cages are brimming with oysters bound for a new home. This is the biggest day of reef restoration the Chesapeake Bay has ever seen.
A crane lifts the cages out of eight tanks submerged in the river, where millions of baby oysters — spat, as they’re known — have spent the past week searching for the right shell. One by one, 200 in all, the cages are dragged over to a conveyor belt and dumped out in a sudden clamor. Up the belt they climb as they’re loaded onto the J. Millard Tawes for transport. The vessel served as an icebreaker and buoy tender in its past lives, but today it will carry these mollusks south for 70 nautical miles to the Manokin River, where they’ll get to work breathing life back into the bay. Reasons to be Cheerful looks at the history and the return of oysters to the Chesapeake region.
In the early 1900s, spent oyster shells were piled high at shucking houses throughout this region. Each one represented a piece of reef removed, rapidly degrading the aquatic environment in the process. In the Maryland portion of the bay alone, an estimated 15 million bushels were harvested annually to satisfy demand. With a helping hand from nutrient pollution and two ravaging midcentury diseases, excessive harvests decimated the oyster population and the natural habitat formed by the bivalves. By 2011, the population in the bay was estimated at less than 1% of historic levels.
Ben Seal for Reasons to be Cheerful
The mountain of shells forming today on the deck of the J. Millard Tawes might resemble the heaps discarded at oyster bars a century ago, but its purpose is to reverse that complicated history. The decade-long, $100 million initiative, led by the National Oceanic and Atmospheric Administration and slated for completion this year, is the world’s largest oyster reef restoration. It serves as a global model — the “gold standard,” according to Olivia Caretti, the coastal restoration program manager for the Oyster Recovery Partnership, a nonprofit leading the conservation of native oysters in the Chesapeake. This morning, she’s ensuring that all these oysters safely complete their journey, which began in March when they were spawned at the nearby Horn Point Oyster Hatchery and will end when they settle onto reefs in the waters of the Manokin.
The river is one of 10 Chesapeake tributaries targeted by the project, and its 450 acres of restored reef alone would surpass any other undertaking. Today, 23 million spat will be planted into the river to join the cause. The ship sags under their weight, enough that its captain briefly wonders if it’s hit bottom. It’s the team’s largest planting to date, and donuts are in order as part of the celebration.
Ben Seal for Reasons to be Cheerful
“In this era of climate change and environmental degradation, this is a rare success story,” says Stephanie Westby, NOAA’s oyster reef program manager. “We have 1,700 or so acres of healthy oyster reefs that just weren’t there before.”
For most of human history, the Chesapeake Bay, America’s largest estuary, was a thriving aquatic ecosystem and oysters were a keystone species. In the colonial era, they were reportedly so abundant that their reefs pressed up toward the water’s surface, posing a navigational hazard for ships passing through the bay. For centuries, all those oysters supported the bay’s health through their very nature.
Ben Seal for Reasons to be Cheerful
By filtering water, the oysters allowed underwater grasses to absorb the sunlight they needed to flourish, offering habitat to countless fish and the bay’s beloved blue crabs. By eating microscopic plankton, they played a pivotal role in the food web, amassing energy that could be passed on to other marine life. By drawing nitrogen and phosphorus out of the water column, they helped prevent algae blooms and the hypoxic dead zones that sometimes follow in their wake. And by conglomerating into reefs, they brought stability and a welcome habitat for their neighbors in the bay.
For a long time, efforts to revive those valuable contributions to ecosystem health were “scattershot,” Westby says. It was “a half-acre here or there, maybe two or three if we were really rocking it.” When the Obama administration issued an executive order in 2009 targeting the bay’s protection and restoration, it was a “sea change,” she says. The collaboration among state and federal agencies, scientists and environmental organizations shifted into a higher gear. In 2014, the Chesapeake Bay Watershed Agreement created a regional compact to restore 10 tributaries by 2025.
“We set this massive, hairy, audacious goal,” Westby says, “and we didn’t even know what that meant. We just knew we wanted to go big.”
When the project began, the bay’s existing reefs had dwindled to just over 500 acres. By the end of 2024, that number had more than quadrupled. When plantings are completed this year, the total will near 2,500.
NOAA uses nautical charts, sonar and bathymetry — the study of submarine topography — to identify segments of the bay that can sustain rejuvenation. In the best cases, like today, oysters are seeded onto existing reefs that have been degraded. In others, where the hard river bottom is exposed but there’s no reef in sight, the project’s partners build a new substrate, either from stone or shell, to which oysters born in the bay can naturally attach. Westby calls that the “build it and they will come” model. In the most depleted portions, decades of runoff and soft sediment seeping into the bay from its expansive watershed have created what Boze Hancock, The Nature Conservancy’s senior marine habitat restoration scientist, calls “a monoculture of mud.” There, crews have to build a substrate and seed it with juvenile oysters produced at the hatchery.
At the hatchery, which is part of the University of Maryland Center for Environmental Science, manager Stephanie Alexander is bubbly about the big day. To reach this point, she and her staff brought in brood stock in January — drawn from the waters where their offspring will be planted — and gently warmed their water to stir them from hibernation. After spawning in early spring, their larvae were fed a steady diet of algae and phytoplankton in 10,000-gallon tanks until they were mature enough to be filtered out of the water, packed into bundles of 5 million, and taken to the pier to settle into the recycled shells they’ll call home.
A short drive from the hatchery, millions of shells have formed towering peaks, waiting to be reused. They were gathered from restaurants and shucking houses across the East Coast, and many of them were harvested from the bay itself. Reef restoration brings their story full circle.
Ben Seal for Reasons to be Cheerful
“We want the oyster to flourish in the bay,” Alexander says. “If we can get those sanctuaries [established], they will fuel other harvests, like the wild fisheries. So it’s a positive feedback loop.”
A Maryland stock assessment in May determined that the number of adult oysters in the state’s portion of the bay has nearly doubled since the NOAA project commenced, even as harvests have begun surpassing 400,000 bushels — a level rarely seen in the last 30 years. In Virginia, where midcentury harvests brought in 4 million bushels but dropped as low as 20,000 in the 1990s, the harvest has surged back to more than 700,000. The benefits of healthy oyster reefs extend to other fisheries as well, including white perch and striper that hide from predators in the reefs’ crevices. A NOAA study found that juvenile blue crabs are three to four times as likely to survive on a reef as on the sandy bottom, and a study out of Morgan State University estimated that fully mature reefs in the Chesapeake would lead to a 150% increase in the blue crab harvest.
As the chief of the shellfish management division of the Virginia Marine Resources Commission, the permitting agency for restoration, Adam Kenyon is hopeful that reefs will revive the bay’s ecosystem and resuscitate the local economies that developed alongside it.
“It’s ingrained culturally and historically in this area,” Kenyon says. “You have these waterside communities that relied on oysters for not only sustenance but a way of life and a way to make money. A lot of industry and infrastructure couldn’t make it [when populations declined], and these communities suffered for that. That infrastructure was never really rebuilt, and these coastal communities still feel that.”
Although the Chesapeake initiative has tangible human benefits, Hancock says it’s been a powerful force for showing the world that returning oyster reefs to full health is about much more than our own interests.
“The Chesapeake Bay work was really ground zero for recognizing that oysters are not just a fishery,” he says. “The critical piece is the habitat the oysters build. It’s the reef.”
Ben Seal for Reasons to be Cheerful
Hancock, who has been working in critical coastal habitat restoration for 25 years, has welcomed numerous visitors to the Chesapeake region to show them the progress NOAA and its partners, including The Nature Conservancy, have made in the past decade. He’s toured groups from China, Hong Kong, Australia, New Zealand, Germany, Netherlands, England and Scotland, he says, and watched as the lights go on in conservationists’ minds. It’s one thing to read about reef restoration in scientific publications, but being able to “see it, touch it and smell it” gets the imagination going about what might be possible elsewhere. “It’s magic to watch,” he says.
The Chesapeake served as inspiration for Australia to commit to restoring 60 shellfish reefs, and it was influential in the effort to establish oyster reefs on wind farms in the North Sea, Hancock says. As the project has created fertile ground on which others can build their own restoration initiatives, he adds, it’s revealed two important lessons for expanding this work. First, scale is not just possible, but essential to be “ecologically relevant.” Second, it takes a broad and committed partnership to be done right.
“This work is too big for any one person, for any one organization. It has to be a collaboration,” Hancock says. “It has taken hundreds of fishing boats working every day that’s available over hundreds of years to mine the resource down. Putting it back is not something that happens overnight.”
This story was produced by Reasons to be Cheerful and reviewed and distributed by Stacker.
