Obtaining accurate estimates of the total number of Florida manatees has been technically challenging. Best estimates from the 1980s suggested a total population of at least 1200 individuals. Beginning in 1991, the Florida Department of Natural Resources (FDNR) [now the Florida Fish and Wildlife Conservation Commission (FWC)] initiated a statewide aerial survey program to count manatees in potential winter habitat during periods of severe cold weather. These surveys, known as the synoptic surveys, involve a coordinated series of statewide aerial surveys and ground counts of manatees at warm-water refuges and adjacent areas. They are carried out one to three times each winter and are much more comprehensive than those used to estimate a minimum population during the 1980s. The highest two-day minimum count of manatees from these surveys tallied approximately 3,300 manatees in January 2001, but it remains uncertain what proportions of the total manatee population was actually counted (USFWS 2001). Although surveys have been conducted more recently than 2001, the weather conditions for that particular survey were ideal. As a result, the count from that year may provide the best minimum population estimate (USFWS 2007).
On a far more limited basis, it has been possible to monitor the number of manatees using the Blue Spring and Crystal River warm-water refuges. At these locations, numbers have clearly increased since the early 1970s (USFWS 2001 and references therein).
No one has provided updates yet.