TALLAHASSEE (CBSMiami) – South Florida’s often quick by severe cold snaps have taken their toll on the state’s manatee population on again.

According to biologists with the Florida Fish and Wildlife Conservation Commission, a cold-related die-off of manatees in early 2011 set the stage for a third straight year with high numbers of deaths for the species.

The FWC documented 453 manatee carcasses in state waters in 2011.

Of those 453 deaths, 112 of them are attributed to “cold stress”. There were 282 cold-related manatee deaths in 2010 and 56 in 2009.

In the previous five years, cold stress accounted for an average of 30 manatee deaths per year.

Cold weather can weaken manatees’ immune systems and eventually kill them.

The total number of reported manatee deaths in 2011 was the second-highest on record.

Biologists documented a record 766 manatee deaths in 2010 and recorded the third-highest total of 429 in 2009.

“We are concerned about the number of manatee deaths the past three years, including those resulting from exposure to cold weather,” said Gil McRae, director of the FWC’s Fish and Wildlife Research Institute. “Over the next few years, we will use data from monitoring programs to better understand any long-term implications for the population. We will continue to work with our partners to enhance the availability of natural warm-water sites, which are important habitats for the species’ survival,” McRae said.

To learn more about manatee conservation, go to MyFWC.com/Manatee.

To report a dead or distressed manatee, call the FWC’s Wildlife Alert Hotline at 888-404-FWCC (3922).