Florida manatees are recovering from near-extinction but remain heavily threatened by watercraft strikes, with boat propellers causing disfiguring injuries and deaths among individuals in an already stressed population.
Manatees struck by boat propellers suffer severe lacerating wounds that, if survived, cause permanent scarring and potential mobility impairment. Multiple strikes on the same individual compound injuries over a lifetime. Manatees that avoid propeller strikes still face risk from boat hull impacts that cause blunt trauma injuries. The 2021 mass starvation event revealed a new welfare dimension — Indian River Lagoon seagrass die-off from nutrient pollution has eliminated the food source of a major manatee wintering population. Watercraft speed compliance and water quality improvement are the two most impactful human interventions for manatee welfare.