Manatee Scars Come From A Fight They Can't Win

Spot a manatee, the friendly, charming and prehistoric marine animal common in Florida's waters, and you're likely to think they're constantly besieged by sharks or other toothy killers. Many bear heavy scars and other marks of attack. But, as essayist Diane Roberts writes, manatees have no natural predators. What's attacking them? Boat propellers.