FORT LAUDERDALE -- A record number of manatees died this year in Florida, as last winter’s severe cold snap brought water temperatures below the level the animals need to survive.
The Florida Fish and Wildlife Conservation Commission announced Friday that 699 manatees had been found dead in state waters from Jan. 1 through Dec. 5. Of these, 244 are known to have died from cold, with additional cold casualties suspected among the 271 carcasses recovered without a known cause of death.
Environmentalists and state biologists called the high body count a reason to work harder to protect the warm water refuges that keep the endangered marine mammals alive in cold weather, including natural springs and power plant discharge lagoons.
“We are very concerned about the unusually high number of manatee deaths this year,” said Gil McRae, director of the wildlife commission’s Fish and Wildlife Research Institute, in a statement. “Maximizing access for manatees to natural warm-water sites will continue to be a focus for the FWC and our partners moving forward.”
Manatees are creatures of sunny climates, with Florida standing at the northern end of a range that extends south to the Brazilian coast.
There is no word yet on any manatee deaths from the cold of the past few days. State officials say it typically takes a week or so for carcasses of cold-stressed manatees to turn up.
When the water temperature remains below 68 degrees for an extended period, manatees develop skin lesions, stop eating, undergo a slowing of their metabolism, develop infections and die, said Martina DeWit, a veterinarian with the state wildlife commission.
Last winter’s cold was so severe, she said, that most manatees didn’t go through all these stages but simply died quickly from severe hypothermia.
During cold snaps, manatees flock to warm water, including two power plant lagoons in Fort Lauderdale and one in Riviera Beach. During one cold day in January, on a helicopter flight over Broward County, biologists counted 789 manatees next to the power plants and just 24 in the canals away from the plants, said Pat Quinn, the county’s manatee protection coordinator.
Relatively few of the cold deaths took place in Broward and Palm Beach counties because of the power plants. In Palm Beach County, five manatees died from the cold, said Paul Davis, the county’s manatee coordinator, and in Broward County, there were seven deaths, Quinn said.
Pat Rose, executive director of The Save the Manatee Club, said the news of the cold deaths showed the importance of protecting the manatees’ remaining warm water refuges.
Last summer, for example, a coalition of public and private entities bought Three Sisters Springs, an important warm-water gathering spot on the Gulf coast, so it could be saved from development and added to the Crystal River National Wildlife Refuge.
More springs need to be protected, Rose said, which also means protecting their water flow upstream by preventing excessive withdrawals by cities.
And manatees need to be protecting from harassment at these areas by people boating, fishing, diving or simply trying to annoy them.
“The vast majority of people want to do the right thing,” Rose said. “But it just takes a few people to drive 100 manatees out of a sensitive area.”
Discussions of manatee mortality typically have focused on deaths from ships and boats, with all the attendant controversies over whether to limit dock construction and boat speeds.
But the number of watercraft deaths has declined so far this year, with 78 deaths compared to 97 last year.
State officials said the decline could be a result of the cold, with fewer boats heading onto the ocean and manatees clustered in the warm-water areas.
Statewide manatee counts are higher than ever, with 5,076 counted in the most recent one-day survey.
Officials said the increase in the manatee’s population could account for some of the increase in deaths, but not all of it.
To report an injured, dead, harassed or orphaned manatee, call (888) 404-3922.