Scientists have been listening to dolphins in the waters around New York City. And they’re hearing the sounds of a maritime revival – a staccato of hope. 

A new study led by Columbia University and the Wildlife Conservation Society confirms dolphins are returning to New York Harbor, drawn by a plentiful supply of food, in this case, bunker fish. Researchers dropped underwater microphones into various spots around NYC waters, partly to calculate the scale of the rebound. Dolphins find their meals via echolocation. When the frisky mammals are hunting and eating, their clicks create, to the human ear, a foraging buzz. And these researchers heard a lot of bottlenose buzz. 

In recent years, the dolphins have been joined by humpback whales frolicking offshore, at the busiest seaport on the East Coast. This cetacean comeback, say scientists, may be partly due to climate change and is likely the result of cleaner coastal waters.

The harbor is cleaner today than it’s been in nearly 110 years, according to a 2019 report by New York City’s Department of Environmental Protection. A shift in federal and state laws as well as attitudes is credited with making the waters more hospitable to marine life. The dumping of toxic chemicals and human waste into the harbor has largely stopped. Annual coastal cleanup events now draw thousands of volunteers. Thanks to the Billion Oyster Project, bivalves, which act as natural water filters, are also making a comeback. 

Humans are also taking advantage of the tidal shift. A new 5½-acre park, including Manhattan’s first public beach, is being built on the Hudson River.

“We’re changing a lot of perceptions about what people think about the New York, New Jersey Harbor estuary,” Howard Rosenbaum, director of the Wildlife Conservation Society’s Ocean Giants Program, told the Gothamist.

Indeed, the waters of New York City now credibly offer a portrait of maritime resilience, natural vibrancy, and restored beauty.