An endangered North Atlantic right whale calf was found dead Sunday off Florida's northeast coast, the second such death reported this month, officials said.

Fisheries biologists with the National Oceanic & Atmospheric Administration were towing the whale to shore, where a necropsy was scheduled Monday, said Kim Amendola, a NOAA Fisheries Service spokeswoman.

Recreational boaters reported the whale sighting to the U.S. Coast Guard around 10:30 a.m. about 16 miles off Jacksonville Beach, Amendola said.

Another right whale calf was reported dead off Jacksonville on Jan. 10, NOAA officials said.

Preliminary necropsy results indicate that calf died from a vessel strike, said Barb Zoodsma, a NOAA Fisheries Service right whale biologist.

"The tail had been severed," she said.

Once numbering in the thousands, only about 300 right whales remain in the North Atlantic, Zoodsma said.

In the fall and early winter, the whales leave the North Atlantic waters near Nova Scotia and New England and travel south to the calving grounds off north Florida and south Georgia to give birth.

Calves are about 15 feet long at birth and weigh up to 7,000 pounds, while adult right whales can grow up to 55 feet long and weigh up to 55 tons, Zoodsma said.

Right whales were hunted to near extinction in the 19th century. They got their name from whalers who said they were the "right whales" to hunt because they were easy to approach and their high blubber content kept them afloat after they were killed.

The whales live close to shore, and can become entangled with fishing gear or collide with vessels unaware of their presence, Zoodsma said.

"The calves spend a lot of time at the surface of the water, and that makes them vulnerable as well because they're not submerging and not as quick as other whales at getting out of the way," she said.