Seeing past the red: flawed IUCN global listings for sea turtles

摘要

ABSTRACT: The Red List of Threatened Species, produced by the International Union for the Conservation of Nature and Natural Resources/World Conservation Union (IUCN) classifies the global populations of all 7 sea turtle species, except the flatback Natator depressus, as Endangered or Critically Endangered. However, the IUCN Marine Turtle Specialist Group (MTSG), which carries out the assessments for the IUCN, is experiencing internal debate over the relevance and usefulness of such statements. Assigning a distinct Red List category to the global population, as a single management unit, does not capture the reality of regional and local populations that tend to have different (positive or negative) trajectories. From a technical viewpoint, setting the time scale for assessment at 3 generations, which is 60 to 100+ yr for sea turtles, means few reference points are available for quantifying past changes in abundance. Moreover, it hardly establishes a sense of urgency for action to prevent future changes over long time scales. The application of current Red List criteria, resulting in flawed categorizations, creates problems of credibility. When a species that may number in the millions in an ocean basin is classified as being at the same ‘very high risk of extinction in the wild,’ as a species represented by just a few individuals, there is something fundamentally wrong with the assessment system. We suggest that MTSG members desist from using the current Red List criteria to generate implausible global assessments of extinction risk and instead concentrate their efforts on developing more realistic and credible criteria, perhaps for application at the regional level.