Meanwhile, on land, the Komodo dragon is moving closer to oblivion.
The IUCN Red List of Threatened Species is the “gold standard” for measuring how close animal and plant species are to dying out.
Tuna have been at the forefront of efforts to make fishing practices more sustainable.
Most types of tuna were deemed at threat of extinction in 2011.
However, populations of sharks and rays are continuing to plummet.