All previous estimates for Florida's manatee population are now out the window.
The state's marine science laboratory announced Wednesday that the annual winter aerial survey counted more than 5,000 manatees huddled in springs and power-plant outfalls. That's 1,200 more than the previous record, set just last year.
That doesn't mean that many manatees were born in a year, though. Biologists credited this month's extended cold front for producing ideal conditions for counting the manatees, which tend to congregate in warm-water areas when the temperature drops below 65 degrees.
A team of 21 biologists from 10 organizations took to the air last Thursday and Friday. They counted 2,779 manatees on Florida's Atlantic Coast and 2,288 on the Gulf Coast, for a total of 5,067. Last year's record high was 3,807.
Next year's total could drop again, depending on how cold the winter turns out to be.
"We may not get weather like this again for 50 years," said Holly Edwards of the Fish and Wildlife Research Institute in St. Petersburg.
Edwards said that while the aerial surveys are not a census, and provide only a minimum number for the population, this year's count is a clear sign that the manatee population has grown in the past 30 years.
"This is absolutely an increase in the population," agreed Pat Rose, executive director of the Save the Manatee Club.
The number counted exceeds the number of manatees that Florida's remaining habitat is supposed to be able to support. A 2003 computer model produced for the U.S. Fish and Wildlife Service found that the state could support at most 5,025 manatees, primarily based on the availability of power plants and springs that provide them a warm haven from cold weather.
"The high count this year shows that our long-term conservation efforts are working," Florida Fish and Wildlife Conservation Commission Chairman Rodney Barreto said.
Boating industry officials could not be reached Wednesday for comment. In the past, when the aerial surveys turned up a higher count than the year before, they have frequently called for removing manatees from the endangered list and eliminating boat-speed zones.
Rose contended it would be wrong to cite the increased population as a reason for easing off the regulations. But he predicted federal officials will now "take a long, hard look" at lowering manatees' status from "endangered" to "threatened," something they talked about doing three years ago.
When manatees were first included on the federal endangered list in 1967, it wasn't because of the size of their population.
The then-chief of the National Aquarium, a St. Petersburg native named Craig Phillips, cautioned federal biologists that manatees "may actually be more abundant than is believed at present, due to the fact that it is one of the most difficult of all totally aquatic mammals to observe in the wild."
Instead, federal officials classified it as endangered 43 years ago because of the loss of habitat and because of such threats as speeding boats. Both are still considered major threats by biologists.
Last year the number killed by boats set a record: 97. Scientists estimate that two-thirds of all manatees carry scars from surviving boat collisions — some of them 20 times or more.
The first attempt to count Florida's manatees from the air occurred during the summer of 1973, when pioneering manatee biologist Daniel "Woodie" Hartman calculated that he and his assistants found between 800 and 1,300. Years later, Hartman said that was at best "a guesstimate."
The first wintertime aerial survey, in 1976, counted 780 manatees. In 1991, state officials conducted the first official statewide survey and found 1,268 — but a month later, they counted 1,465, a sign that weather conditions played a big role in how many manatees might be spotted from the air.
The number counted by the annual survey has gone up and down since then, usually depending on how cold the weather is. But Phillips' warning remains pertinent. Scientists say that most manatees remain submerged, and thus virtually invisible to spotters, even when the planes circle over repeatedly.
"It's almost like flying over New York City on a busy day and seeing how many people are in the streets and using that to estimate how many people are in the city, without seeing how many are inside the buildings," longtime federal biologist Bob Bonde, co-author of Florida Manatee: Biology and Conservation, said in a 2007 interview.
Craig Pittman can be reached at (727) 893-8530 or firstname.lastname@example.org.