FORT MYERS, Fla., (UPI) -- Marine biologists said Friday they are puzzled by an unknown infection that is killing manatees in the waters of southwest Florida. The state Department of Environmental Protection said at least 33 dead adult sea cows have been found in the past 10 days.
Scientists earlier this week set up a makeshift morgue at the Ding Darling National Wildlife Preserve on Sanibel Island, where biologists have been taking samples of each animal's organs, blood and tissue, sending them off to labs for further examination.
"We won't know very much about what's killing them until we hear what the labs have to say," said DEP spokeswoman Kathalyn Gaither.
The results were expected to be known by early next week.
"All we know now is that they all died of pneumonia," said Gaither, but it is not known what caused the manatees to become stricken. The epidemic so far has been confined to a 25-mile stretch near the city of Fort Myers, along Florida's Gulf coast.
Officials checked for water and air pollution in the area, but found nothing out of the ordinary. Not since scientists began keeping records 20 years ago have so many manatees died in such a short period. Mortality among Florida manatees is normally 150 to 200 annually.
Both males and females have died, and all were well-nourished with no other disease or injury.
"This is happening very rapidly," said Dr. Scott Wright, a marine mammal pathobiologist with DEP.
"The tissue samples that we've collected are telling us a story that we've never seen or heard before."
DEP Secretary Virginia Wetherell said her agency was pulling out all the stops in an effort to halt the rash of manatee deaths.
"We're working around the clock to determine the exact cause of death, and hope to learn how we can prevent this from happening in the future," said Wetherell.
TALLAHASSEE, Fla., March 26 (UPI) -- More dead manatees were found Tuesday in waters along Florida's southwest Gulf coast, the apparent victims of the same mysterious epidemic that killed scores of the endangered mammals earlier this month.
About 20 manatee carcasses have been found since Friday near the city of Ft. Myers, according to the Florida Department of Environmental Protection. The manatee death toll in the region since March 5 now stands near 80, marking the first time on record so many of the sea cows have died in such a short period.
Mortality among Florida mantees normally runns between 150 to 200
annually. Necropsies indicated the otherwise healthy mammals perished from a pneumonia-like illness that bloodied and scarred their lungs. Marine scientists have not been able to identify the source of the illness, but have said unusually cold weather and an outbreak of red tide in the Gulf of Mexico did not play a role in the deaths.
"We've narrowed the source down to a virus or bacteria, but we have not been able to determine the specific virus or bacteria involved, or its source," said Edie Ousley, spokeswoman for DEP.
As part of their effort to determine the cause of the epidemic, state biologists have sent tissue samples from the manatee carcasses to laboratories as far away as Holland for analysis. Authorities last week had thought the epidemic was coming to an end, when the number of dead manatees being found dropped from from about 10 a day to one or two daily.
But the number of fresh carcasses began rising again on Friday, according to the chief of the Florida Marine Research Institute in St. Petersburg.
"We are concerned now that there's some continuing mortality from the epidemic," said Ken Haddad.
"We just don't have a feel for what this means," he added.
The epidemic has so far been confined to a 25 mile stretch near Ft. Myers, and scientists doubt the illness will spread to manatee populations elsewhere in the state.
Manatees are an endangered species whose population in Florida waters numbers about 2,600. In previous years, the leading killer of manatees has been motorboat propellers.