Arlington, VA — Once written-off as functionally extinct in the eastern tropical Pacific Ocean, researchers in Central and South America are lauding the discovery of adult Critically Endangered hawksbill turtles (Eretmochelys imbricata) living among in-shore mangrove estuaries rather than the coral and rocky reefs for which they previously known to inhabit. This never-before-seen habitat adaptation by this population helps explain why the species went undetected in the region for decades.
The findings were detailed in a report published this month by the international conservation journal Biology Letters and represent the culmination of a three-year grassroots effort to track movements of adult female hawksbills to identify important areas for nesting, migration and feeding in the eastern Pacific Ocean from the southern U.S. to Peru. The results mark the most complete set of observations on habitat use by hawksbill turtles in the eastern Pacific to date.
Widely considered among the most endangered sea turtle populations in the world, little attention had been paid to hawksbill population declines or habitats in the eastern Pacific since the early 1980s, when scientists concluded that they had become "rare to non-existent in most localities". Long exploited for the commercial trade of its elaborately colored shell, the hawksbill turtle has faced numerous other threats in the region including egg harvest, coastal habitat destruction, and fisheries bycatch (the accidental capture of non-target species in fishing gear).
Lead report author Alexander Gaos, a conservation scientist from San Diego State University, initiated the research to address the lack of information. Collaborating with individual scientists and organizations throughout the region, including Conservation International (CI), Gaos and colleagues formed Iniciativa Carey del Pacifico Oriental (ICAPO). Also known as the Eastern Pacific Hawksbill Initiative, ICAPO is dedicated to increasing data collection on the species, prioritizing research sites, identifying urgent threats and spearheading conservation efforts throughout the region.
Hawksbills were believed to live in the region, but had long evaded detection by scientists, likely due to their unique life-history strategy of moving into these mangrove habitats, which is seen nowhere else in the world and made them extremely difficult to find.
"We were really shocked to see that adult hawksbills weren't even using coral or rocky reefs or any habitats that were even remotely similar to habitats they associate with in other parts of the world," Gaos said. This research builds on a 'rediscovery' of the species in the eastern Pacific based on ICAPO's region-wide effort to identify key nesting sites and in-water sites for hawksbills. Observers found nesting beaches for the hawksbills in El Salvador, Nicaragua, Costa Rica and Ecuador.
"These findings show that conservation of mangrove estuaries and coastal wetland habitats is important not just for rare species like hawksbills, but also for the critical ecosystem services these habitats provide," said Dr. Bryan Wallace, Director of Science for the Marine Flagship Species Program at Conservation International, and a co-author of the study who helped to compile, organize, and analyze the reports from throughout the region. Mangrove habitats not only act as nurseries for juvenile marine animals, many of which are important food sources for humans, like fish and crabs, but they also serve as land buffers from storms and natural water filters.
This discovery of the population's reliance on confined mangrove habitats is both bad news and good news for these hawksbills. The proximity of these habitats to human communities places the hawksbills under severe threats throughout the region like the use of deadly explosives for fishing, rampant egg collection for human consumption and excessive habitat degradation.
Despite the increased threats, this discovery of hawksbills concentrating their activities in these small estuaries, rather than large swaths of open-coast or offshore ocean areas like other sea turtles, means targeted protection efforts focused on these areas can pay big dividends for this population. These findings also provide a clue as to where researchers may encounter more hawksbills in the region, improving opportunities for conservation and recovery of the population.
The success of the ICAPO initiative is owed to its collaborative, grassroots nature involving participants from more than a dozen institutions, including governments NGOs, universities, and local communities from Mexico to Peru, including key support from the Southwest Fisheries Science Center of the National Oceanic and Atmospheric Administration, the National Fish and Wildlife Foundation, US Fish and Wildlife Service, Paso Pacífico and Fauna & Flora International - Nicaragua, Fundación Zoológica de El Salvador and Equilibrio Azul in Ecuador. This collective effort and the new information it is generating are giving hawksbills more than a fighting chance at survival.
"Where some have been found already, many more might be hidden away, still escaping detection by us," added Gaos. "That tells us that the ICAPO network needs to continue thinking outside the box and working together to solve these mysteries, focusing in areas where hawksbills haven't traditionally flourished, but are surviving anyway."
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Notes for Editors:
Iniciativa Carey del Pacifico Oriental (ICAPO) is a network of individuals and organizations from eleven countries, ranging from local fishermen to conservationists to heads of government, with one thing in common; a desire to learn about and save hawksbill turtles in the eastern Pacific Ocean. ICAPO was officially formed in June of 2008 at the "First Workshop of the Hawksbill Turtle in the Eastern Pacific" held in Los Cóbanos, El Salvador. Visit www.hawksbill.org for more information.
Conservation International (CI) — Building upon a strong foundation of science, partnership and field demonstration, CI empowers societies to responsibly and sustainably care for nature, our global biodiversity, for the long term well-being of people. Founded in 1987, CI has headquarters in the Washington, DC area, and nearly 900 employees working in more than 30 countries on four continents, plus 1,000+ partners around the world. For more information, visit www.conservation.org, and follow us on Twitter: @ConservationOrg or Facebook: www.facebook.com/conservation.intl