Boat propellers are the leading cause of Florida manatee injury and death, creating visible scars on virtually all surviving adults and requiring sustained speed restriction policies.
Boat propeller wounds cause severe traumatic injuries - deep lacerations that may sever flippers or penetrate body cavities. Non-fatal strikes leave permanent scarring that can be seen on virtually every adult manatee. Injured manatees face reduced swimming efficiency, higher infection risk, and physiological stress from repeated trauma exposure. The 2021 die-off from seagrass loss demonstrated that multiple compounding threats - boat strikes, algal blooms reducing food, and cold stunning - simultaneously reduce manatee welfare across the population.