This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

JERSEY CITY, N.J. — A dead humpback whale was spotted in the Hudson River Wednesday evening, a day after the federal government warned boaters to be on the lookout for the massive mammals.

The dead whale can be seen floating in the water off Jersey City, opposite Port Liberty. It’s unclear how long the carcass has been in the water, which is  partially decayed.

The spotting of humpback whales has been common recently in the New York region, with a sighting of the whales on Tuesday on Long Island Sound. The National Oceanic and Atmospheric Administration Fisheries  later advised boaters in Connecticut and New York to be on a lookout for them in the sound.

Anyone who spots one is advised to stay at least 100 feet away.

NOAA says humpbacks create bubble clouds to corral their prey and then lunge through the center to swallow the small fish. Fishermen or boaters in these bubble patches run the risk of colliding with a whale as it rapidly approaches the surface. The collision can gravely injure the whale.

The Associated Press contributed to this report.