Seal of Renewal

The ecological restoration of an ancient wetland on Manhattan’s northern tip has created a haven for herons, owls, leopard frogs—and one very charismatic aquatic mammal.

A seal shifts on the warm rock, pointing his plump belly to the New York sunshine. He’s luxuriating beside a small tidal estuary where sea and fresh waters meet. A gaggle of people has gathered on a nearby wooden boardwalk to sneak a glance and a photo. The seal pays them no attention as he smacks the limestone with his flipper and angles his whiskered snout skyward.

It’s not unusual for a pinniped, or carnivorous aquatic mammal, to set up shop at an estuary like this one—the habitat serves up abundant food and provides a safe place for seals to haul out of the water to rest and regulate their body temperatures. The location of this particular seal, in the waters of Muscota Marsh near Inwood Hill Park, however, is something of an anachronism.

Back before boardwalks and phones with built-in cameras, before animal-friendly legislation and the development of Manhattan Island even, a seal sunning itself here may have been normal. But up until recently, the area was a dumping ground. An estimated 90% of the coastal wetlands in New York City had been lost to the drainage and backfilling that comes with urban development, according to a 2012 report by the mayor’s office.

What kind of development? Consider the city’s 850 miles of subway tunnels dug at the start of the 20th century—the displaced debris had to go somewhere. Much of it was dumped in the lowlands, around the perimeter of Manhattan Island, says Matthew Palmer, a senior lecturer in the department of ecology, evolution and environmental biology at Columbia University.

But under all that debris, there was potential—the sort of life-giving land that sustains.

Sealy the harbor seal in Muscota Marsh, New York City
Sealy was last spotted in Muscota Marsh in August 2019. If he doesn’t return, it will likely be because he has moved onto popular breeding grounds farther north. Still, harbor seals return to familiar locations or home bases, and Sealy could come back after. Photo by Trish Mayo

Salt marshes are unsung environmental heroes, one of nature’s most biologically productive landscapes. Found along every coast in the U.S. and fringing the shallow shores of estuaries, salt marshes capture and filter fertilizers, heavy metals and other pollutants. Grasses and other vegetation grow in thick masses on the tidal flats and provide a habitat for fish and other animals. Those grasses decompose and feed the ocean food chain, starting at the bottom with invertebrates, which then feed small fish, on and on, up until you reach a predator like a harbor seal.

Such marshes had been prized by the Lenape people, who used Manhattan Island and its natural resources long before Europeans arrived. Working with the land, they could plant crops, hunt and fish every year before moving to different settlements for the winter months.

When Henry Hudson captained The Half Moon into the area now known as New York Harbor in 1609, these superfood salt marshes were everywhere: the Lower East Side, the Harlem Plains and what is now Inwood Hill Park. Wetlands covered 10% of Manhattan Island, according to maps at that time.

That’s a far cry from the metropolis we know today. In New York City, only 5,600 acres of wetlands remain, a small fraction of its historical area, according to a May 2021 report by the Natural Areas Conservancy. The nonprofit, an REI Co-op partner, conserves and restores wetlands and forests in New York City, including Inwood Hill Park in Manhattan.

It’s a story repeated across the U.S., where wetlands have been disappearing over the decades due to land development, pollution, invasive species and other factors. The continental U.S. has lost more than half of its wetlands since the 1600s when marshes covered about 220 million acres.

Although New York City remains mostly marsh-free today, perhaps public perception is shifting.

Where wetlands were once discounted or filled in, people now view them as environmentally and socially valuable and are working to protect them. The federal government passed the Clean Water Act in 1972, which sought to repair and maintain the health of the nation’s waters (including wetlands) by stemming pollution. New York legislators also passed laws to protect wetlands from filling and dredging in 1975.  

Columbia University C
Columbia University agreed to rehabilitate and create access to the Muscota Marsh area near Inwood Hill and the Henry Hudson Bridge. Photo by Ethan Strell

Not only do wetlands provide habitat for wildlife and protect the land against erosion and storms, but they also serve as beautiful, quiet places where people can seek respite or enjoy recreational activities like fishing, birding or kayaking. In urban areas like New York City, they provide access to open spaces for millions who live within walking distance of them. Such habitats also contribute to the area’s climate resilience by storing carbon and reducing flood risk.  

By 2000, the Department of Parks and Recreation had laid out plans to restore Manhattan’s vanishing lowlands. “Since then, NYC Parks has completed over 35 salt marsh restoration projects to enhance over 150 acres of salt marsh on Parks property,” Rebecca Swadeck, the senior wetlands restoration program manager for the parks department, told Uncommon Path.

One such project: the Muscota Marsh. Nestled at the northern tip of Manhattan adjacent to Inwood Hill Park, the tidal estuary is the “last remnant” of saltwater marshes that once surrounded the island, according the NYC Parks.

In 2010, Columbia University began negotiating with the New York City Department of Parks and Recreation to expand its boating facilities near Muscota. But to meet a city zoning requirement, the college agreed to rehabilitate the area—including a unique ecosystem that included both a saltwater and freshwater marsh—and allow public waterfront access.

Though the city parks department manages more than 30,000 acres of undeveloped land (or over 14% of city land), access is often an issue for residents and visitors. It tends to require grassroots efforts to put in trails and the sort of infrastructure needed to enjoy public lands as we think of them.

Working with biologists, restoration ecologists and others, project workers planted native wetland plants, improved the dock and opened access along the banks of the Harlem River. To filter stormwater runoff, they built a tiered system that treats the water before it empties into the river.

Spuyten Duyvil in the Bronx
Spy the spit of Spuyten Duyvil in the Bronx from Inwood Hill Park in Manhattan. Photo by Ethan Strell

In 2014, Muscota Marsh—which comes from the Lenape term meaning “place in the reeds”—officially opened to boaters, pedestrians, birders and other visitors. The waterside green space features native gardens and tidal flats with walking paths and boardwalks. Observation decks showcase views of the Henry Hudson Bridge and the sheer rock faces of the Palisades, but the real stars of the show are the fauna that have made a grand return.

Wading birds like snowy egrets and great blue herons tiptoe through the shallows, while ospreys and various owls perch in old-growth tulip trees. Leopard frogs hide in the reeds, and, if you’re lucky, you’ll even spot a very charismatic harbor seal hamming it up for visitors along the rocks or boardwalks.

Known to locals as Sealy, the recognizable pinniped first bobbed his head in the waters of the new park in 2017. For two summers, locals watched him haul out on the dock or rock slabs to sunbathe and, seemingly, smile for photos. During those warmer months, he was likely getting fat and healthy before winter trips away from his home base.

It’s unclear exactly why Sealy ended up in Muscota Marsh or why he frolicked there for so long during the summers. (He was last spotted in the marsh in August 2019.) We do know that cleaner waters offered plenty of food for Sealy—and all that points back to the life-giving nature of Muscota.

Northern Mockingbird
A northern mockingbird perches in a tree in the recently restored Muscota Marsh area of New York City. Photo by Ethan Strell

There’s perhaps no better ambassador for Muscota Marsh and wetland restoration than Sealy. He’s what’s called an indicator species, meaning that his health (and that of harbor seals, in general) says a lot about the health of the food chain beneath him. In other words, if Sealy is smiling for cameras, then the ecosystem around him is flourishing.

When it is, people flock to this one-acre park to snap Instagram-worthy photos of the seal and other unique wildlife, also reaping the benefits of the estuary’s rehabilitation. In addition to scoring animal sightings, they discover nature in the densest city in the country and whatever R&R they may glean from it.

It’s the best kind of snowball effect, one that’s good news for pinnipeds and humans alike.

Read more about REI Co-op’s rewilding efforts.