TALLAHASSEE, Florida -- Biologists with the Florida Fish and Wildlife Conservation Commission’s (FWC) Fish and Wildlife Research Institute documented 429 manatee carcasses in state waters in 2009. A combination of factors contributed to the high total, as indicated by record high numbers in several of the categories of manatee deaths.
The high number of manatees affected by cold stress during the winter months of 2008-2009 can, in part, explain the higher-than-average number of manatee deaths last year. Biologists documented a record high of 56 cold stress-related deaths in 2009, which was more than double the five-year average.
Biologists also documented high numbers of watercraft-related and perinatal (newborn) deaths – the two most commonly documented causes of death in 2009. Biologists documented 97 watercraft-related deaths and 114 newborn deaths. The preliminary data indicate the numbers for both categories were at a record high for a calendar year.
Given the high count of manatees from 2009 aerial surveys, it might be perceived that the high number of deaths is simply because of a larger manatee population. The situation is not that simple. Both the carcass totals and the annual counts from statewide aerial surveys are considered minimum numbers only, and they cannot be used to calculate long-term population trends. However, models used by the FWC to assess the status of the species indicate the manatee population is stable or increasing in most areas of the state in the near term. Yet, manatees continue to face a combination of human-related and natural threats. To maintain the species into the future, the FWC will continue to monitor threats such as watercraft strikes and loss of warm-water habitat, which models indicate can profoundly affect the manatee population.
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. FWC law enforcement, in cooperation with partner agencies, uses knowledge of local boating habits, well-posted speed zones and up-to-date manatee information to focus on-the-water enforcement operations. Enforcing manatee protection zones and informing boaters about manatee conservation is a priority for the FWC.
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