5. West Indian Manatee
The West Indian Manatee was falling victim to the propellers of U.S. Navy’s powerful C-tractor tugboats at Naval Submarine Base Kings Bay in Georgia until the early 1990′s, when the navy began to install propeller guards which not only protected the manatees but also improved efficiency. Now all tugs and other small vessels at Kings Bay have propeller guards. Other protective measures include speed limits, no-entry areas, and population monitoring in and around the bay.
Image: West Indian Manatee with calf, US Fish and Wildlife Service via wikimedia.









