West Indian manatees have recovered from endangered to threatened status, but boat strikes, cold stress syndrome, and red tide events continue to cause significant individual suffering and mortality.
Manatees affected by red tide ingest brevetoxins through their seagrass diet causing neurological effects including seizures, disorientation, and loss of ability to maintain buoyancy. Affected animals surface repeatedly gasping, unable to dive, and strand on beaches in progressive neurological distress before dying. Cold stress syndrome from sudden temperature drops causes immune suppression and secondary pneumonia - a slow debilitating disease requiring weeks of intensive rehabilitation if animals are to survive. Boat propeller injuries cause deep lacerations and blunt trauma from hull strikes. Each of these welfare harms falls on an animal that is gentle, slow-moving, and entirely unable to avoid the threats that humans create in their aquatic environment.