Could nature be healing?

A group of rays — also known as a “fever” — was spotted swimming through Newtown Creek, a notoriously filthy estuary of the East River, last weekend.

“I have not heard of anybody seeing rays in the creek before,” said Willis Elkins, executive director of nonprofit the Newtown Creek Alliance. The group had shared a now viral clip of the rays — which appear to be of the native cownose variety — in the creek’s murky waters.

“It’s hard to say exactly what the significance of any sort of specific new wildlife sighting is,” Elkins said, but it’s still “very exciting.”

Newtown Creek, which runs between Brooklyn and Queens, is among America’s most polluted waterways. The refineries that once lined its banks dumped, leaked and spilled between 17 million and 30 million gallons of oil into its waters over decades — significantly more than the Exxon Valdez disaster, which is considered one of the largest environmental disasters in U.S. history.

But since Newtown Creek was declared a Superfund site in 2010, much work has been done to clean its squalid shores.

Oysters, clams, bass, moonfish, swans, egrets, robins and more have all been observed in and along the creek in recent years, according to a working document maintained by the Newtown Creek Alliance.

So far, 2026 has “actually been a pretty good year, because we saw some horseshoe crabs up in one of the tributaries where the water quality conditions are even worse than the mouth of the creek,” Elkins said. He added that there have also been many eel sightings this year.

Taken individually, however, incidences of wildlife aren’t necessarily good signs. The dolphin spotted in the Gowanus Canal in 2013, for instance, swam into the canal not because its conditions had improved but because it was lost and dying. Sludgie the Whale had a similar tale of woe.

But a whole fever of rays is a better sign.

“Most of the time, especially if it’s a [group], they’re coming because there’s food,” Elkins said. “The whole group swimming as one was really awesome to witness.”