The turtle called "Splinter" was found off the Key Largo coast with a 3-foot spear in her neck, tangled in a buoy rope and in distress.
Sea turtles are among the oldest creatures on the planet. However, they are facing significant threats from human activities.
The dead sea turtles are considered endangered by the U.S. Fish and Wildlife Service, as well as by Mexican officials.
Turtles face many hazards in the water, including plastic pollution and accidental harm or death in encounters with commercial fishermen.
Sea turtles are more like us than we thought.
If their status changes, protections for the leatherbacks could be reduced.
A loggerhead turtle in the Pacific almost died after getting caught in $53 million of cocaine.
At least 1,000 turtles die every year from plastic in the ocean.
Dozens of species in the reserve cannot be found anywhere else in the world.
The exact cause is still a mystery, though a prime suspect has been named.
Sea turtle populations seem to be on the rebound after decades of work.
Australia's Reef is home to more than 6,000 species.