For decades, the IUCN Marine Turtle Specialist Group has debated the utility and appropriateness of single global listings on the Red List of Threatened Species for widely distributed, long-lived marine turtle species. The main disadvantage of global listings is that they fail to describe and assess wide variations in marine turtle population dynamics, extinction risk, and conservation status across subpopulations, so can lead to misleading and confusing results. Today marks an important breakthrough for marine turtle Red List assessments. The IUCN Red List Authority has published the new leatherback Red List assessments, which, for the first time, include subpopulation-level listings—not simply a global listing. This is the first time that any marine turtle species has been officially assessed, globally, to the subpopulation level, and sets an important precedent for other marine turtle Red List assessments, as well as red listing of other widely distributed, long-lived species, such as sharks, marine mammals, and seabirds.
These assessment results reflected the wide variation in leatherback subpopulation status, accurately highlighting subpopulations that have declined greatly over time, as well as those that are small and /or geographically restricted, and merit Critically Endangered status. These subpopulations require effective protection and reduction of threats to ensure their future existence.
Globally, leatherback status is now Vulnerable. East Pacific, West Pacific, Southwest Atlantic, and Southwest Indian Ocean subpopulations were listed as “Critically Endangered,” Northwest Atlantic leatherbacks were listed as “Least Concern,” and Northeast Indian Ocean and Southeast Atlantic subpopulations were listed as “Data Deficient.”
We are working on Red List updates to several other marine turtle species using this subpopulation approach, as well as other improvements to how we interpret and apply Red List criteria to marine turtle assessments.