http://www.phillyburbs.com/pb-dyn/news/111-11072008-1617749.html

BRISTOL TOWNSHIP - A dead manatee was found earlier this week near the banks of the Delaware River in Croydon.

The mammal, an endangered species concentrated in Florida, was spotted in cold waters Sunday in Neshaminy State Park near the park's marina ramp in Bristol Township.

Rescuers worked for more than an hour Monday morning removing the manatee from the river bank, according to Josh Swartley, the park's manager.

This is the first for Neshaminy State Park, he said. While manatee sightings up north are becoming more common, a Florida nonprofit organization confirmed that manatees swimming around Pennsylvania waters are rare.

Swartley said the manatee was not full-size. The average adult manatee grows to about 10 feet long and weighs between 800 and 1,200 pounds, according to Save the Manatee Club, a national nonprofit organization established by former Florida governor and U.S. senator Bob Graham and singer Jimmy Buffet.

Katie Tripp, the organization's director of science and conservation, said that despite a manatee's large size, the mammals often develop immune system problems when in water below 68 degrees.

“It almost becomes a hypothermia-type situation,” she said.

Although it's not clear if that's what happened here, the National Weather Service said the Delaware River's temperature has been about 46 or 47 degrees.

There's been an increase in manatee sightings in the Northeast lately, according to Save the Manatee Club. A manatee was rescued Oct. 11 from Sesuit Harbor in Dennis, Mass., but died the next day en route to a medical treatment facility at SeaWorld Orlando. Other sightings include manatees around Baltimore and in North Carolina.

“Something seems to be changing. Either that, or we're just seeing them more,” Tripp said.

“These recent sightings highlight the importance of public involvement in locating wayward manatees and coordinating with authorities in an effort to ensure timely rescues,” she said.

According to the organization, 264 manatees died through Oct. 12 from a variety of causes. Of those, 71 were attributed to watercraft accidents, which account for about 25 percent of all manatee deaths, experts say.

Although they are listed as endangered, manatee populations are growing, some researchers say. The highest population count was taken in 2002, when about 3,300 manatees were counted in Florida.