Mysterious ailment killing manatees on East Coast

Headline Goes Here

Four manatees and needed help from Florida Fish and Wildlife after getting themselves stranded in a shallow marsh Monday afternoon.   VIDEO: Stranded Manatees Returned Home

MELBOURNE, Fla. - A mysterious ailment is killing off dozens of manatees on the Florida's East Coast.

The Tampa Bay Times reports that state biologists have been unable to pinpoint what killed the manatees.

State Fish and Wildlife Research Institute experts say that since last July, 55 manatees have died of similar symptoms in the Indian River Lagoon area - 25 of them in just the past month.

These deaths are not red tide related, although more than 150 manatees have died due to the toxic algae along Florida's West Coast.

Experts suspect the East Coast deaths are connected to back-to-back blooms of a different kind of harmful algae, one that has stained the Indian River Lagoon a chocolate brown.

Copyright 2013 by The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.