Your good news of the day: whales are now a common sight in the waters around New York.

But wait until one washes up dead on a popular beach.  Get the dynamite!

For the first time in a century, humpback whales have returned to the waters of New York harbor. And not just occasionally, either. They're coming in enough numbers that a company can reliably trot tourists out to the ocean—within sight distance of Manhattan’s skyscrapers—to see them.

“Because of the improvement of the water quality, algae and zooplankton have multiplied, giving good food for the menhaden [a small oily forager fish beloved by whales], which have returned in numbers that the fishermen say they have not seen in their lifetimes,” Paul L. Sieswerda told PopSci. Once a curator at the New York Aquarium, Sieswerda has since founded Gotham Whales, an organization that conducts tours and monitors the presence of whales, seals, and dolphins in NYC. “Our surveys show an exponential increase in the number of whales since 2011 when we first began our studies," he said. "Prior to that, whales were only seen intermittently."