These are the tracks of a sea turtle. She slowly made her way up to dry sand on the beach. After spending hours using her flippers to make a hole in the sand, she laid her eggs.
She then crawled her way back to the sea and will return next year to this approximate area to repeat the process.
If you see a nest in this area that is not roped off or is not tagged, call the Florida Oceanographic Coastal Center and report it. (772) 225 0505
The Center also offers Sea Turtle Tours during the nesting season.