Florida Fish and Wildlife Conservation Commission researchers are waiting for a front cold enough to allow for the annual statewide aerial survey of manatees.

Traditionally, every January the FWC and volunteers keep an eye on the weather and wait for cold enough conditions that prompts manatees to cluster tightly in warm-water havens. When the water temperatures drop into the 60s, the marine mammals seek out warmer waters in springs, canals and near power plants.

“They’re gearing up now,” FWC spokeswoman Wendy Quigley said Monday.

The weather this month will decide if there will be an aerial survey.

January of 2010 and 2011 both proved extremely good years for the aerial surveys due to extreme cold. However, January 2012 saw no weather cold enough to merit an aerial survey, so none was taken, researchers say.

The downside to the winter cold is the potential hike in manatees dying of cold stress.

According to the FWC, with prolonged exposure to water temperatures below 68 degrees, manatees can suffer hypothermia, shock and other ailments. And in some cases, cold stress can be fatal.

In 2011, of the 453 reported manatee deaths, researchers determined 114 died of cold stress. From Jan. 1 to Dec. 21, 2012, the FWC reported 58 of the 372 Florida manatee mortalities were due to cold stress.

Cold stress and red tide have led to recent manatee deaths, FWC researchers report.

Martine DeWit, a senior researcher with FWC’s pathology lab in St. Petersburg, said Monday the lab is now seeing some signs of cold stress in the Florida Panhandle and some signs of manatees dying from recent red tide algae outbreak in Collier County waters.

In 1996, after large outbreaks and high concentrations of red tide, the state saw a tremendous die-off of manatees in Southwest Florida and discovered that manatees could die from the red tide toxins. The red tide algae can attach itself to seagrasses upon which the manatees feed, DeWit said.

The FWC plans to update its manatee mortality report on its website at myfwc.com later this week. The numbers will increase, but those numbers are still within the normal annual mortalities, DeWit said.

Lee County appears to remain the epicenter of the state’s manatee mortalities due to watercraft compared to all other Florida counties.

So far in 2012, 19 manatees died in Lee County from injuries they received from boats. In Sarasota County waters, no watercraft deaths were reported. In Charlotte County waters, four died from watercraft injuries.

When asked why so many manatees die in Lee County of watercraft injuries, DeWit gave a simple answer.

“You have a lot of boats and a lot of manatees,” she said.

Email: reilly@sun-herald.com