The 12 Healthiest Sea Turtle Populations

Green turtles haul ashore to bask on the remote coast of western Australia. The green turtle population in this relatively undeveloped region is thriving thanks to low levels of threat from human activities and strong protections by the Australian government. © Kellie Pendoley

The following list was published in The State of the World's Sea Turtles Report Vol. 7 in 2012 and represents the 12 healthiest sea turtle populations in the world. This analysis was made possible by the priority-setting efforts of the Burning Issues (BI) Working Group of the IUCN Marine Turtle Specialist Group, which created a framework for delineating sea turtle populations globally (Regional Management Units, or RMU's) and then evaluated, compared, and organized sea turtle RMU's within the context of a conservation "priorities portfolio".

The RMU framework breaks down globally distributed, widely migrating sea turtle species into smaller, biogeographically defined units above the level of a single nesting beach yet below the level of species. RMUs are functionally independent subpopulations that include breeding adults, as well as juveniles. RMUs vary in their levels of risk and threat, as well as their conservation status, and thus provide a more suitable scale for developing strategies for research and conservation than do global-level species assessments.

For more information on the priority-setting initiatives that undergird this assessment, see the SWOT Report article: “Getting our Priorities Straight.”

See also related SWOT Report article: The 11 Most Threatened Sea Turtle Populations

Green turtles (Chelonia mydas)

East Pacific Ocean

Key nesting sites: Galápagos Islands (Ecuador) and Mexico

This population underwent a perilous decrease in numbers in past decades because of substantial turtle harvest for their meat and eggs throughout the region, but especially in Mexico. However, because stricter controls on trade of turtle products were enforced, green turtles have made a remarkable comeback in this region. Although still a fraction of their historic population size, green turtles in the East Pacific are no longer in danger of disappearing any time soon.

Southwest Atlantic Ocean

Key nesting site: Brazil

Green turtles, like other sea turtle species in Brazil and the southwest Atlantic in general, are a conservation success story. Once depleted because of extensive consumption of eggs and meat, as well as accidental capture in fisheries, green turtles are on the rise in this region. Although coastal net by-catch is still a threat, collaborative conservation efforts throughout the region are ensuring a positive outlook for this population.

Southeast Indian Ocean

Key nesting site: Australia

Although they have not been monitored for long, these green turtles are abundant and fairly isolated. They nest along the rugged and remote coast of Western Australia; although consumption of eggs and turtles by humans poses a threat to them on beaches and in the water, the chances are good that these turtles will be around for a while.

South Central Pacific Ocean

Key nesting sites: French Polynesia and several Pacific Island nations

Although population trends are not well known, the population is not facing many serious threats. Future monitoring and conservation work will provide a better view of this population’s status, but for now, things are bright for these Pacific Island green turtles.

West Central Pacific Ocean

Key nesting sites: Palau, Guam, and Micronesia

These green turtles are spread across this vast oceanic island region, with nesting sites dotting isolated beaches and remote coral atolls. But they also share islands with humans, and traditional cultures in this region value turtles, sometimes for consumption. At the moment, this population is healthy, but better assessments of their status will help future conservation efforts.

Hawksbill turtles (Eretmochelys imbricata)

Southeast Indian Ocean

Key nesting site: Australia

As for green turtles in this region, nesting in isolated places gives these hawksbills an advantage that allows them to thrive. Although monitoring has been occurring only in recent years, threats to this population appear mild, making its future bright.

Southwest Indian Ocean

Key nesting sites: Seychelles and British and French overseas territories.

Unlike their cousins in other parts of the world, these hawksbills benefit from solid long-term monitoring and good protection at major nesting sites and in their coral reef habitats. As with all hawksbills, exploitation of their shells for handicrafts and jewelry is a constant threat; although this population is historically depleted as a result, it is healthy and recovering at present.

Southwest Pacific Ocean

Key nesting site: Australia

Nesting sites for this population are confined to Australia, but hawksbills are thriving along the continent’s shores and in its coral reefs. Exploitation of hawksbills for their shells remains a threat, and impacts from future climate changes might be problematic, but at present, these are healthy hawksbills.

Leatherback Turtles (Dermochelys coriacea)

Northwest Atlantic Ocean

Key nesting sites: Trinidad, Guyana, French Guiana, Suriname, Costa Rica, and Panama

In contrast to their cousins on the other coast of the Americas, this leatherback population is huge and increasing nearly everywhere. With the exception of the declining nesting colony in Costa Rica and Panama, leatherbacks are swarming nesting beaches and feeding areas throughout the wider Caribbean and North Atlantic. Conservation efforts to maintain beach protection and to address significant by-catch issues are the keys to keeping these leatherbacks on this list.

Southeast Atlantic Ocean

Key nesting site: Gabon

Recent studies of the major nesting sites in Gabon have established this population as the biggest in the world for leatherbacks. Despite threats from by-catch and oil exploration in parts of their distribution, conservation efforts are under way to foster cooperative, international management in Gabon and neighboring countries to protect leatherbacks and other sea turtles in this region.

Loggerhead Turtles (Caretta caretta)

Northwest Indian Ocean

Key nesting site: Oman

Despite being the largest loggerhead nesting population in the world, monitoring efforts have become consistent only recently, which means that we still know relatively little about this population. Threats from fisheries by-catch appear to be severe, but the sheer abundance of nesting loggerheads in this region seems to have the upper hand for now.

Olive Ridley Turtles (Lepidochelys olivacea)

East Pacific Ocean (arribada populations)

Key nesting sites: Mexico, Nicaragua, and Costa Rica

Harvest for meat, eggs, and skin was rampant in the past and resulted in shocking declines in the seemingly endless abundance of olive ridleys in the East Pacific. Although some mass nesting sites have not recovered, others have held strong and remained incredibly abundant. The biggest rookery in the world hosts hundreds of thousands of nesting females each year! Serious threats still exist in this region, especially because of fisheries by-catch, but this population of sea turtles is presently the most abundant on the planet.

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This article originally appeared in SWOT Report, vol. 7 (2012). Click here to download the entire article as a PDF.

See related SWOT Report article: The 11 Most Threatened Sea Turtle Populations