ALSO Officials inspect a dead manatee.
Manatees are the most studied of Florida's rare creatures.
Since 1974, their carcasses have been trucked to a manatee morgue in St. Petersburg, where scientists categorize and catalog every death. Over the decades, hundreds have been tracked by radio transmitter, their seasonal searches for warm waters as closely charted as military cruises. And, with all that, biologists still can't say for sure how they're doing or how many there are. Chilly weather and clear waters created what biologists called optimum conditions for an aerial survey, with an unusually high percentage of manatees concentrated near warm water outflows of power plants where they were easy to spot. The annual aerial count, often cited as a population figure, just isn't a reliable gauge, says Lynn Lefebvre, project leader for the Sirenia Project.