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, according to the Florida Fish and Wildlife Conservation Commission.
Biologists with the research arm of the Conservation Commission documented 453 dead manatee carcasses in state waters in 2011.
During the past three years, biologists documented the highest levels of cold-related manatee deaths, with the "cold stress" category accounting for 112 in 2011, 282 in 2010 and 56 in 2009.
In the previous five years, cold stress accounted for an average of 30 manatee deaths per year, a news release said.
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, according to the conservation commission.
"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 Conservation Commission’s Fish and Wildlife Research Institute, in a news release. "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," he added.
Conservation commission researchers, managers and law enforcement staff work closely together to evaluate mortality data and identify necessary actions.
Managers focus on actions that can reduce risks to manatees and protect foraging and warm-water habitats.
Informing boaters about manatee conservation and enforcing manatee-protection zones are priorities for the FWC.
To report a dead or distressed manatee, call the Conservation Commission’s Wildlife Alert Hotline at 888-404-FWCC (3922).