Sea turtle swimming. NPS photo. Sea turtle hatchling swimming in front of Fort Jefferson. NPS photo by Brett Seymour. All five of these species were once more abundant; however, all five species are now listed as either threatened or endangered under the Endangered Species Act of 1973. Loggerhead, green, and hawksbill turtles can sometimes be spotted lounging on the surface of the sea on the trip between Key West and Dry Tortugas National Park. The name Las Tortugas was changed to Dry Tortugas on nautical charts used for navigation to indicate to mariners that no fresh water was available on the islands. The name change had nothing to do with how wet, dry, or thirsty the local sea turtles were.