NEW YORK Lost 220,000 Acres of OYSTER REEFS in 100 Years — Then SCHOOLKIDS Did Something IMPOSSIBLE!

[00:00:00]In the year 1880, on the wide tidal waters of New York Harbor, between the southern tip of Manhattan and the marshes of New Jersey, a working fisherman could pull up a single dredge full of oysters that would fetch enough money at market to feed his family for a week.

[00:00:18]New York Harbor in the late 1800s was, by every available historical measure, the oyster capital of the world.

[00:00:26]According to historical estimates compiled by the New York Public Library and the Billion Oyster Project, the harbor in its peak years held approximately half of all the oysters on the planet.

[00:00:38]220,000 acres of living oyster reefs blanketed the harbor floor.

[00:00:44]In some estimates, as much as 350 square miles of continuous oyster habitat.

[00:00:51]The reefs lined the shores of Manhattan, filled the East River, ran out under what is now JFK Airport, and stretched along the New Jersey coast almost to Sandy Hook.

[00:01:03]Oysters were so abundant in 19th century New York that they were the cheapest food in the city.

[00:01:09]Street vendors sold them out of carts.

[00:01:12]Oyster sellers on Canal Street served them by the barrel.

[00:01:16]The bivalve was the universal poor man's protein, eaten by stevedores, factory workers, immigrants, school children.

[00:01:25]New York consumed roughly 1 million oysters every single day.

[00:01:31]The oysters were not just food. They were what biologists today call ecosystem engineers. The same category as the bison of the Great Plains, the beaver of the river, the prairie dog of the colony.

[00:01:45]They built the reefs they lived on. The reefs they built filtered the water. The water they filtered supported fish, crabs, and dozens of other marine species.

[00:01:57]The reefs themselves softened storm waves and protected the shoreline from erosion.

[00:02:02]The entire harbor ecosystem in real, measurable terms was held up by the oyster.

[00:02:09]By the year 1927, all of that was gone.

[00:02:14]The last commercial oyster bed in New York Harbor was officially closed by the New York City Department of Health that year after decades of catastrophic over-harvesting, dredging, sewage contamination, and industrial pollution had reduced what had once been the largest oyster ecosystem on the Eastern Seaboard to, in scientific terms, functionally extinct.

[00:02:38]Not endangered, not depleted, gone.

[00:02:43]The reefs that had taken thousands of years to build had been scraped, polluted, and harvested out of existence in less than a century.

[00:02:53]For the next 87 years, New York Harbor was, in the assessment of every marine biologist who studied it, ecologically dead at the bottom.

[00:03:04]The fish populations had collapsed, the crabs were rare, the water was opaque with sediment and human waste.

[00:03:11]By the 1970s, the harbor was so polluted that swimming in it was banned in most areas, and several stretches were officially designated as not safe for any human contact at all.

[00:03:25]And then, in 2014, two teachers at a small public high school on an island in the middle of New York Harbor decided to try something that almost nobody at the city, state, or federal level believed could work.

[00:03:40]They were going to bring the oysters back.

[00:03:43]All of them.

[00:03:45]1 billion oysters returned to New York Harbor by the year 2035.

[00:03:51]Funded mostly by donated restaurant shells, built by their own students.

[00:03:57]I'm Edmund Hale, and what I want to tell you about today is one of the strangest, most under-covered, and quietly most ambitious urban ecological restoration projects happening anywhere in the modern world.

[00:04:11]The Billion Oyster Project.

[00:04:14]How two teachers and a few dozen high school students set out to rebuild one of the largest lost ecosystems in American history.

[00:04:23]What the science has shown 11 years into the project, and the bigger lesson buried inside this whole thing about what kind of restoration is actually possible, even in the middle of one of the most heavily polluted urban waterways in the United States.

[00:04:40]Stay with me, because what they have actually accomplished, measured in oysters, in acres of restored harbor floor, in marine species returning on their own to waters that has been considered ecologically dead for almost a century, is something I think is going to genuinely change how you understand what coastal restoration can look like.

[00:05:01]Let me start by giving you a sense of what the Eastern oyster, Crassostrea virginica, actually does.

[00:05:08]Because to understand why this restoration matters, you have to understand why losing the oysters in the first place was so much more than a fishing problem.

[00:05:19]The Eastern oyster is a small, fist-sized mollusk that lives on the bottom of brackish coastal waters from the Gulf of Mexico up through Eastern Canada.

[00:05:30]It anchors itself to a hard surface, historically the shells of other oysters, and spends its entire adult life in one place, filtering water through its gills.

[00:05:42]A single adult oyster filters somewhere between 30 and 50 gallons of water every single day.

[00:05:50]According to figures cited by NOAA and Governor Kathy Hochul's office, a healthy oyster reef the size of a football field can filter roughly a million gallons of water per day.

[00:06:03]What the oysters do to that water is what makes them in real biological terms irreplaceable.

[00:06:09]They strip out suspended algae. They remove organic waste. They sequester nitrogen and phosphorus. They make the water clearer, which allows light to penetrate deeper, which allows underwater grasses to grow, which provides habitat for fish, which feeds birds, which produces the kind of full coastal ecosystem that humans have for most of the last several hundred years slowly destroyed.

[00:06:36]But the oysters do something even more remarkable than filter water.

[00:06:41]They build structure.

[00:06:44]When oyster larvae settle, they attach to the shells of older oysters and grow on top of them.

[00:06:50]Over generations, this creates three-dimensional reefs, sometimes meters tall, that fundamentally reshape the bottom of the bay.

[00:07:00]Those reefs become habitat for almost everything else.

[00:07:04]Mud crabs hide in the crevices. Small fish use them as nurseries. Larger fish hunt around them.

[00:07:11]The reefs' slow currents capture sediment and protect shorelines from storm waves.

[00:07:18]A healthy oyster reef is not just a place where oysters live.

[00:07:22]It is the physical infrastructure that holds an entire estuarine ecosystem together.

[00:07:29]This is why when the oysters disappeared from New York Harbor in the early 20th century, the harbor did not just lose a fishery. It lost the underlying structural and ecological scaffolding that had supported every other species in the system.

[00:07:45]The water became cloudy because there was nothing filtering it. The fish populations collapsed because their nursery habitat was gone.

[00:07:53]The shoreline became more vulnerable to storms because the reefs that had been softening the wave energy were no longer there.

[00:08:01]The whole system fell apart, not gradually, but rapidly.

[00:08:06]And the consequences shaped the harbor for the next century.

[00:08:11]I want to pause here because this is the part of the story I think most people genuinely don't know.

[00:08:18]The same pattern that happened in New York Harbor happened almost simultaneously on the largest estuary on the East Coast of North America, Chesapeake Bay.

[00:08:30]According to figures published by NOAA's Chesapeake Bay Oyster Restoration Program, the Chesapeake has lost approximately 99% of its historic oyster numbers.

[00:08:42]Stephanie Westby, the program's manager, said it about as clearly as anyone could in a 2024 interview.

[00:08:50]When it comes to oysters, we're down to 1% of our historic number of oysters.

[00:08:56]And when you lose 99% of your oysters, you lose 99% of your reef habitat, and you lose 99% of everything.

[00:09:07]Across the entire Eastern Seaboard of the United States, from New York Harbor to Chesapeake Bay to the Apalachicola in Florida, the same collapse played out over the same 100-year period. The oysters that had supported entire coastal economies and entire estuarine ecosystems were scraped, polluted, and disease-stressed into near extinction.

[00:09:31]By the end of the 20th century, the great oyster ecosystems of the American Atlantic coast were in real, measurable terms, gone.

[00:09:42]Which brings us to a high school on Governors Island in the middle of New York Harbor in the year 2014.

[00:09:49]The Urban Assembly New York Harbor School is, on paper, a fairly ordinary New York City public high school.

[00:09:56]It is operated by the New York City Department of Education. It serves about 500 students.

[00:10:03]What makes it unusual is its mission and its location.

[00:10:07]It was founded in 2003 by a man named Murray Fisher, who had spent years thinking about what kind of school New York Harbor itself deserved.

[00:10:18]The school sits on Governors Island, a small piece of land in the middle of the harbor, accessible only by ferry.

[00:10:26]Its students study marine biology, aquaculture, professional diving, vessel operations, ocean engineering, and other water-focused career and technical disciplines that most American public schools do not offer.

[00:10:41]One of the teachers Murray hired in the late 2000s was a young aquaculture instructor named Pete Malinowski.

[00:10:50]Pete had a relevant background. He had grown up the second of six children on a tiny island off the northeast coast of Long Island called Fishers Island, where his parents ran a small oyster farm.

[00:11:03]He had spent his entire childhood around oysters, learning the science of them at home in a way that, by his own admission, no school had ever managed to teach him.

[00:11:14]He had struggled in conventional school settings. He had thrived at the oyster farm.

[00:11:20]When he moved to New York City as a young adult and ended up teaching aquaculture at the Harbor School, he brought with him a deep, practical understanding of how to grow oysters that almost no one else in New York City's educational system possessed.

[00:11:35]In 2008, Pete began having his students grow oysters at the Harbor School.

[00:11:41]The original purpose was educational.

[00:11:44]The students needed something to grow.

[00:11:46]Oysters were what Pete knew.

[00:11:49]The school had a hatchery, a few tanks, and access to the harbor.

[00:11:53]They started small, a few hundred animals, then a few thousand.

[00:11:59]What Pete and Murray began to notice over the next several years is that the oysters they were growing were doing something nobody had expected.

[00:12:07]They were surviving.

[00:12:10]New York Harbor by 2008 was significantly cleaner than it had been in the 1970s and 1980s.

[00:12:18]The Federal Clean Water Act, passed in 1972, had over the following decades dramatically reduced the volume of raw sewage and industrial waste being discharged into the harbor.

[00:12:31]The water was still polluted. It was still not safe for swimming in many areas, but it was clean enough by the late 2000s that oysters placed in the harbor could grow.

[00:12:43]In 2014, Pete and Murray formalized what they had been informally piloting.

[00:12:49]They founded a nonprofit, separate from but partnered with the Harbor School, called the Billion Oyster Project.

[00:12:57]The name was, in their own admission, deliberately almost absurd.

[00:13:02]The goal, to restore 1 billion live oysters to New York Harbor by the year 2035.

[00:13:10]I want to be clear about something.

[00:13:12]In 2014, when Pete and Murray announced this goal, almost nobody in the New York environmental community took them seriously.

[00:13:21]1 billion oysters is a number so large that it sounds, on first hearing almost cartoonish.

[00:13:29]To put it in perspective, the entire current global production of farmed oysters worldwide is approximately 5 million tons.

[00:13:39]The Billion Oyster Project was not proposing to grow oysters for food.

[00:13:44]They were proposing to put 1 billion live breeding filter feeding oysters back into one of the most polluted urban waterways in the United States.

[00:13:55]Restore the reefs they used to live on and rebuild from scratch one of the largest functionally extinct ecosystems in American history.

[00:14:05]And they were going to do it with high school students. 11 years later, I want to tell you exactly what they have accomplished. Because the actual numbers, when you look at them, are remarkable. As of the most recent available data, the Billion Oyster Project has restored approximately 135 million live oysters to New York Harbor.

[00:14:27]They have installed 18 separate restoration sites scattered across the five boroughs of New York City.

[00:14:34]They have restored approximately 19 acres of harbor bottom. They have partnered with over 100 New York City public schools engaging more than 11,000 students directly in the science of oyster restoration. They have collected over 2 million pounds of empty oyster shells from a network of 70 to 80 New York City restaurants, diverting those shells from landfills and using them as substrate for new oyster reefs. The National Science Foundation awarded the project a $5 million grant. And on July of 2024, the New York State Governor's Office announced that the Jamaica Bay Oyster Restoration Site, which had started in 2016 with a population of just 20,000 oysters, had grown, almost entirely through natural recruitment and reproduction, to 122 million oysters. That last number is, I think, the single most important detail in the entire story.

[00:15:37]Because it represents what biologists call natural recruitment. It means that the oysters Pete's team placed in the water in 2016 did not just survive. They reproduced.

[00:15:50]Their larvae found the reef structures.

[00:15:52]The larvae successfully settled. They grew into adult oysters. Those adult oysters reproduced again. And what started as 20,000 animals has, in 8 years, become a self-sustaining breeding population of over 100 million. That is the definition of ecological restoration. Not just adding animals back, but adding animals back and watching them take over the system on their own. I want to be honest, though, about what the Billion Oyster Project has and has not solved. Because the version of this story I've sometimes seen circulate online overstates what 1 billion oysters can actually do. The oysters in New York Harbor are not safe to eat.

[00:16:38]The water is still too polluted with industrial residues and nitrogen for the oysters' tissue to be safely consumed by humans. The Billion Oyster Project's boats are deliberately marked with the name Attractive Nuisance. A reference to the regulatory concern that someone might mistake the project's oysters for food. The harbor is cleaner than it has been in over a century. It is not, however, restored to anything close to its pre-industrial chemistry. The oysters are doing real ecological work, but they are doing it in water that is still, by every honest standard, significantly compromised. The project has also had to abandon two of its restoration sites over the past decade after the local conditions turned out to be unsuitable. Disease, particularly two parasites called Dermo and MSX, which have devastated oyster populations across the Atlantic seaboard, continues to be a real and ongoing threat. The genetic diversity of the founding population is small since the project deliberately uses oyster larvae from existing New York Harbor populations rather than introducing animals from elsewhere in order to avoid the risk of introducing invasive species. And the bigger question, whether the harbor can ever support a fully wild, self-sustaining oyster fishery again, is still genuinely open. The project's most honest assessment is that even 1 billion oysters returned by 2035 would represent perhaps 1 or 2% of the historic population. But here is what they have proven and what I think is genuinely consequential.

[00:18:21]They have proven that the ecology of New York Harbor is not permanently broken.

[00:18:26]They have proven that given the right conditions and the right substrate, the eastern oyster will return to water that has been considered functionally dead for nearly a century.

[00:18:38]They have proven that a coastal urban ecosystem, even one as heavily damaged as New York Harbor, retains enough underlying ecological function to begin rebuilding itself when humans give it the structural foundation to do so.

[00:18:56]And they have proven it without billions of dollars in federal funding, without massive corporate engineering projects, without any of the apparatus that conventional environmental restoration usually requires.

[00:19:12]They have proven it with a small nonprofit, a partner high school, 11,000 students, 2 million pounds of recycled restaurant shells, and a relentless decade of patient on-the-water work.

[00:19:29]The Chesapeake Bay restoration, by way of comparison, has cost over $100 million across 10 years, involves multiple federal agencies, the Army Corps of Engineers, NOAA, the states of Maryland and Virginia, several universities, and a coordinated political commitment going back to the 2014 Chesapeake Bay Watershed Agreement.

[00:19:55]As of 2025, 10 major Chesapeake tributaries have been successfully restored.

[00:20:02]It is, by NOAA's own description, the largest oyster reef restoration project in the world.

[00:20:11]And it works.

[00:20:13]The science behind it is solid. The recoveries are real.

[00:20:18]But it required an enormous coordinated institutional effort.

[00:20:24]The Billion Oyster Project is, in many ways, the smaller, scrappier, and more replicable model.

[00:20:31]A school, a hatchery, a partnership with restaurants, engaged community of students and volunteers, and a willingness to start small and grow.

[00:20:44]It is the kind of model that, in theory, could be applied to almost any degraded urban coastal ecosystem anywhere in the world.

[00:20:54]The deeper lesson buried in this whole story, I think, is one I find genuinely encouraging.

[00:21:01]We tend, as a culture, to assume that the great environmental disasters of the last two centuries are basically permanent.

[00:21:10]That what we have damaged at urban scale in industrial water bodies like New York Harbor or Chesapeake Bay will stay damaged.

[00:21:20]The Billion Oyster Project and the Chesapeake Bay restoration and a growing number of similar projects from Maine to Florida to the Gulf Coast suggest that this is not necessarily true.

[00:21:33]Some of these systems, given the chance, want to come back.

[00:21:39]The oysters of New York Harbor have been declared extinct three times in living memory.

[00:21:45]They were declared extinct in 1927 when the last commercial bed was closed.

[00:21:51]They were declared functionally extinct again in the 1970s when even the broken remnant populations seemed to fail.

[00:22:01]They were declared a permanent loss again in the 1990s when most marine biologists believed the harbor's chemistry was simply too far gone.

[00:22:13]And then, 11 years ago, two teachers and a few dozen high school students started growing oysters in tanks on an island in the middle of the harbor, dropping them carefully into the water, and watching what happened.

[00:22:30]Today, there are over 135 million oysters living in New York Harbor.

[00:22:37]The Jamaica Bay site alone holds 122 million.

[00:22:42]Wild oysters have been found reproducing on the project structures, which is the biological signal that the system is no longer dependent on human inputs to keep going.

[00:22:55]The harbor is the cleanest it has been in over 100 years.

[00:23:00]The oysters are coming back their own.

[00:23:03]And the original goal, 1 billion oysters by 2035, which sounded in 2014 like a piece of poetic exaggeration, looks, 11 years later, like something genuinely achievable.

[00:23:19]The lesson, in plain terms, is this.

[00:23:23]Sometimes the most powerful environmental restoration does not come from the top down.

[00:23:30]It does not come from a billion-dollar federal program, or a massive engineering project, or an international agreement. It comes from a small group of people in one specific place who decide to do the boring, patient work of rebuilding what was lost. One substrate, one larva, one reef at a time.

[00:23:53]And it works.

[00:23:55]Not all the way.

[00:23:56]Not perfectly. Not without limits.

[00:24:00]But it works.

[00:24:02]If this story changed how you think about what coastal restoration is actually possible, let me know in the comments. And subscribe, because the comeback stories unfolding across the natural world, particularly in the urban ecosystems we have spent the last two centuries breaking, are stranger, slower, and more important than the headlines tell you.

[00:24:27]There are more of these stories than you would ever guess.

[00:24:30]I'm Edmund Hal.

[00:24:32]Thanks for watching.