Rare Hawksbill Turtles Discovered Living in Mangroves

A Hawksbill turtle swims off cost of Cozumel, Mexico. © Simone Rossini

This is a Hawksbill turtle swimming in a coral reef, a place it is expected to be found. However, Hawksbill turtles have found a new place to live -- mangroves. Previously unknown to live in this type of ecosystem, it seems the sea turtles have come up with a new survival tactic.

A very rare eastern Pacific hawksbill sea turtle after being measured and tagged for future identification in Reserva Natural Estero Padre Ramos, Nicaragua, 2010. © CI/Photo by Dr. Bryan Wallace, Marine Flagship Species Program

The Hawksbill sea turtle mainly dines on sponges, and it is the only marine animal who focuses on them as a food source which means it plays an important role in coral ecosystems. However, mangroves are also home to corals, and according to a new report published in Biology Letters and provided by Conservation International, they're also home to these rare turtles, a fact previously unknown.

"...[N]ew satellite tracking data on female hawksbills from several countries in the eastern Pacific revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species."

Not only does it shed light on important information about the species, but also brings to the forefront yet another vitally important role mangroves play for coastal ecosystems. Yet mangroves are under just as much threat as the sea turtles found living there.

Post-nesting hawksbill turtle equipped with a satellite tag returning to an estuary in Estero Padre Ramos, Nicaragua. © Alexander Gaos

Thanks to the satellite tracking system used on these turtles, as shown in the photo above, the use of mangroves by sea turtles as places for foraging food has opened up all new possibilities for studying -- and saving -- these turtles.

"Hawksbill turtles (Eretmochelys imbricata) are critically endangered and the majority of hawksbill habitat use and movement research to date has been centred in the Wider Caribbean and Indo-Pacific regions...As recently as 2007, hawksbills were considered functionally extirpated in the eastern Pacific Ocean, based on scarce reports of their presence and the sparse coral reef distribution in the region...This study represents the first initiative to track individuals from this remnant hawksbill population and describes novel habitat use that will inform regional conservation efforts."

Indeed, conservation efforts are required, and fast. Sea turtles are under enormous threat as they're caught as bycatch in fisheries, and lose their habitats to overfishing, pollution, and other human encroachment -- including poaching and rampant sea turtle egg collection. Now add to that the significant loss of mangroves not only in Hawksbill territory but around the world. Without immediate conservation efforts to preserve the mangrove and coral habitats and prevent loss from fishing and egg poaching, there isn't much hope for this iconic marine animal.

Conservation International is hosting Sea Turtle September, where you can learn more about this and other studies, information about specific species, and help save sea turtles.