Friday, January 29, 2010

Record Cold = Record Count, Record Deaths

Unusually cold weather in December and January may be responsible for 2 new manatee records in Florida. Not long after a statewide synoptic survey counted a record high of over 5000 manatees (see January 20 News Release, below), FWC reported more than 100 manatee deaths during the first 23 days of the year (see January 26 News Release, below).

Adopt Conch, Sirenian International's Ambassador from Florida, online at Photo (c) Doug Perrine,

FWC records unprecedented number of cold-related manatee deaths

News Release, January 26, 2010
Contact: Carli Segelson, 727-896-8626

The cold period that began Jan. 2 and lasted nearly two weeks continues to impact Florida manatees. Biologists with the Florida Fish and Wildlife Conservation Commission's (FWC) Fish and Wildlife Research Institute documented more than 100 manatee carcasses in state waters from the beginning of the year through Jan. 23.

Biologists report that the preliminary cause of death for 77 of these animals is cold stress. Although pending final review, the number of cold-stress deaths exceeds the previous record of 56 for that category in a single year, which was set in 2009.

In addition, researchers note exposure to cold this year likely contributed to the deaths of several newborn manatees, classified as "perinatal." Researchers continue to recover and examine carcasses, so the total is expected to rise; however, the rate should slow down as water temperatures warm.

The recent cold snap exposed manatees in Florida to cold water temperatures. Exposure to low temperatures over a period of time can cause a condition called manatee cold-stress syndrome, which can result in death.

Since receiving the initial reports of cold stress-related manatee deaths on Jan. 7, FWC biologists have been working closely with FWC law enforcement and partner agencies, including the U.S. Fish and Wildlife Service, to respond to the high number of manatee deaths. FWC staff members and conservation partners are working extended hours to recover and transport carcasses to the FWC's Marine Mammal Pathobiology Laboratory in St. Petersburg. There, biologists perform necropsies, or animal autopsies, on each manatee to determine the cause of death and gather additional data. Some carcasses that cannot be transported are examined in the field.

Since the cold weather conditions began to affect Florida, FWC researchers have worked diligently to rescue several manatees and continue to respond to reports of distressed manatees.

"We are deeply concerned about these impacts on manatees and other fish and wildlife," said FWC Chairman Rodney Barreto. "We appreciate all the time and effort being put into the process of documenting the effects of this unprecedented event and ask the public to assist in the effort by reporting dead or distressed manatees to the FWC Wildlife Alert Hotline at 888-404-FWCC (3922)."

Exceptional weather conditions lead to record high manatee count
News Release, January 20, 2010
Contact: Carli Segelson, 727-896-8626

After nearly two weeks of record cold weather in Florida, biologists counted an all-time-high number of manatees during the annual synoptic survey the week of Jan. 11.

The Florida Fish and Wildlife Conservation Commission's (FWC) Fish and Wildlife Research Institute reported a preliminary count of 5,067 manatees statewide. A team of 21 observers from 10 organizations counted 2,779 manatees on Florida's East Coast and 2,288 on the West Coast. The final numbers will be available at the end of February, following verification of the survey data.

This year's count exceeded the previous high count from 2009 by more than 1,200 animals. The survey conditions were favorable for aerial observations in both years, but were especially favorable this year as a result of the extended period of cold weather.

"This year's high count reflects the influence that weather has on aerial survey results," said FWC biologist Holly Edwards. "The record-breaking cold temperatures helped to bring many more manatees to the warm-water sites than in previous years. In addition, the calm, clear weather conditions on the days of the survey helped us to see and count record numbers."

The goal of the synoptic survey is to count as many manatees as possible. The survey results provide researchers with a minimum number of manatees in Florida waters at the time of the survey. Synoptic results are not population estimates and should not be used to assess trends.

While this year's results do not mean the manatee population grew by more than 1,200 animals in a single year, they do tell researchers there are at least 5,000 manatees in Florida waters. The FWC is encouraged to have counted so many manatees. The high count is consistent with models that show the manatee population is growing or stable in most areas of the state.

"Counting this many manatees is wonderful news," said FWC Chairman Rodney Barreto. "The high count this year shows that our long-term conservation efforts are working."

The cold weather that helped researchers obtain the record high count also highlighted the importance of warm-water habitat for the species. During the recent cold snap, biologists noted unusually large numbers of manatees gathered in the warm-water sites for extended periods of time. FWC researchers, managers and law enforcement officers closely monitored the large numbers of manatees dependent on these sites. To maintain the species into the future, the FWC will continue to monitor threats such as loss of warm-water habitat which, models indicate, can profoundly affect the manatee population.

For additional information about manatee conservation, visit For more information on manatee mortality research, visit

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