The leatherback sea turtle (Dermochelys coriacea) is the world's largest reptile and the deepest-diving turtle, capable of crossing entire ocean basins. As the only sea turtle that feeds primarily on jellyfish, it is particularly vulnerable to plastic bag ingestion and the welfare consequences of ocean plastic pollution.
Leatherbacks that ingest plastic bags develop intestinal blockages causing progressive obstruction, perforation, and internal organ damage. Death from plastic obstruction is prolonged — turtles may survive weeks with impaired digestion. Their backward-facing spines in the oesophagus prevent regurgitation of ingested plastic, trapping it permanently. Boat strikes cause traumatic shell and soft tissue injuries that are difficult to treat given their size. Nesting beach disturbance causes abandonment of late-stage nesting attempts — a significant energy cost after the female has spent weeks migrating to the beach. Conservation welfare requires simultaneous ocean plastic reduction and nesting beach protection.