West Indian manatees face chronic welfare threats from boat propeller injuries and cold stress events that kill hundreds of animals each year.
Manatee welfare harms are visible and individual: propeller strikes leave distinctive parallel scars that lacerate muscle and bone, with survivors facing infection, impaired swimming, and chronic pain. Cold stress syndrome causes progressive muscle failure and respiratory compromise as manatees become too cold to move toward warm water refugia. Starvation from seagrass loss — driven by water quality degradation from agricultural runoff — adds a third major welfare burden that intensified dramatically in 2021. Each of these threats is human-caused and human-addressable: boat speed limits, water quality regulation, and warm water refuge management can all reduce manatee suffering significantly.