Underwatertimes.com News Service - December 10, 2010 17:57 EST
florida manatee

A Florida manatee at at Homosassa Springs State Park. Credit FWC.

The cold weather earlier this year led to a record high number of manatee deaths in 2010. From the beginning of the year through Dec. 5, biologists with the Florida Fish and Wildlife Conservation Commission's (FWC) Fish and Wildlife Research Institute (FWRI) documented 699 manatee carcasses in state waters.

This preliminary data indicates the number of manatee deaths documented from Jan. 1 through Dec. 5 is nearly double the five-year average for that time period.

The "cold-stress" category accounts for 244 documented manatee deaths, which were caused by exposure to low water temperatures. However, it is likely the cold temperatures also contributed to many of the 203 deaths in the "undetermined" category and the 68 deaths in the "unrecovered" category.

The 2010 cold-related manatee die-off was unprecedented in both numbers and geographic extent. A large number of manatee deaths identified as cold-related occurred throughout much of the state, as far south as the Everglades and the Florida Keys.

Although the cold weather was a natural event, this die-off underscores the importance of warm-water habitat for the long-term survival of the species.

"We are very concerned about the unusually high number of manatee deaths this year. Data from our monitoring programs over the next few years will tell us if there are long-term implications for the population," said the director of FWRI, Gil McRae. "The cold-related deaths this past winter emphasize the importance of warm-water habitat to Florida's manatees. Maximizing access for manatees to natural warm-water sites will continue to be a focus for the FWC and our partners moving forward."

The cold weather likely was responsible for fewer watercraft-related mortalities earlier in 2010. However, later in the year, watercraft-related deaths trended higher than average and as a result, the year-end total for watercraft-related deaths will likely be similar to that of previous years.

FWC 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 habitat. The FWC's Division of Law Enforcement, in cooperation with partner agencies, uses knowledge of local boating habits, well-posted speed zones and up-to-date manatee information as part of its on-the-water enforcement operations. Enforcing manatee protection zones and informing boaters about manatee conservation is a priority for the FWC.