Humpback whales are returning to New York’s City waterways after almost a century  a welcome sight for the sore eyes of urban dwellers.

These whales were nearly extinct from the waters of New York Harbor. But now a population of at least 100 whales has taken up residence near enough shore to serve as an exciting sightseeing attraction for onlookers.

The Hudson River is the primary tidal estuary that feeds from the city into the ocean, receiving and providing for a constant exchange of water. Its historically high pollution levels date back to the mid 1900s before John Cronin and the Riverkeeper. Since that time period, drastic changes have resulted in cleaning up the city’s waterways.

#NYC0055 aka #gotham the NYC Humpback Whale is outside city limits looking in.

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Combined legislation highlighted by the Federal Clean Water Act, the Clean Air Act, New York’s Environmental Conservation Law, and the establishment of the Environmental Protection Agency have attributed to the massive improvements of the city’s ecosystem over time. And these efforts seem to have paid off.

In addition to legislation regarding environmental policies, limitations on commercial fishing have allowed for a reestablishment of the dwindling fish population, fish that serve as the primary diet for cetaceans, including humpback whales.

“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 stated to Popular Science.

This is great news for the Atlantic ecosystem — and an added bonus for sightseers in New York City.