Study identifies most threatened sea turtle populations

Posted: 5 October 2011

Top sea turtle experts from around the globe announced the results of the first comprehensive status assessment of all sea turtle populations globally in a paper published this week in the online science journal, PLoS ONE.

The study, designed to provide a blueprint for conservation and research, evaluated the state of individual populations of sea turtles and determined the 11 most threatened populations, as well as the 12 healthiest populations.

World's Most Threatened Sea Turtle Populations
Click on image to enlarge. © Conservation International

The report, produced by the IUCN Marine Turtle Specialist Group (MTSG) of the International Union for the Conservation of Nature (IUCN) and supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF), was a collaboration of over 30 experts from 6 continents and more than 20 countries with diverse expertise in all aspects of sea turtle biology and conservation.

Four of the seven sea turtle species have populations among the world's 11 most threatened. Almost half (five) of these populations are found in the northern Indian Ocean, specifically on nesting beaches and in waters within Exclusive Economic Zones (EEZs) of countries like India, Sri Lanka, and Bangladesh. Other areas that proved to be the most dangerous places for sea turtles were the East Pacific Ocean (from the U.S. to South America) and East Atlantic Ocean (off the coast of west Africa).

Leatherback turtles (Dermochelys coriacea) in the East Pacific Ocean are at risk (key nesting sites: Mexico; Nicaragua; Costa Rica). Despite decades of conservation efforts, leatherbacks in the East Pacific have declined by 90% in the past 20 years due to egg consumption and bycatch. Coastal development looms as the next threat to their survival.
Photo © Jason Bradley/

"The report confirms that India is a home to many of the most threatened sea turtles in the world," said Dr. B. C. Choudhury, head of the Department of Endangered Species Management at the Wildlife Institute of India and a contributor to the study. "This paper is a wake-up call for the authorities to do more to protect India's sea turtles and their habitats to ensure that they survive." 

The study also highlighted the twelve healthiest sea turtle populations in the world, which are generally large populations with increasing trends under relatively low threats. Five species among these dozen healthy populations are found in nesting sites and feeding areas in Australia, Mexico, and Brazil. Other areas that harbor healthy turtle populations included the Southwest Indian Ocean, Micronesia and French Polynesia.

"Before we conducted this study, the best we could say about sea turtles was that six of the seven sea turtle species are threatened with extinction globally," said Dr. Bryan Wallace, Director of Science for the Marine Flagship Species Program at CI, and lead author for the paper. "But this wasn't very helpful for conservation because it didn't help us set priorities for different populations in different regions. Sea turtles everywhere are conservation-dependent, but this framework will help us effectively target our conservation efforts around the world."