Mangrove forests, which are unique coastal tree and shrub habitats, are also under threat. They could represent an important breeding and nesting site for the species, which was thought to depend on coral reefs.

A team of scientists that has been tracking the hawksbill turtlesfor three years have found that the critically endangered animals nested in these estuaries.

"For upwards of five decades sea turtle scientists thought hawksbills had [disappeared from] the eastern Pacific Ocean", Dr Gaos told BBC Nature.

"Despite hundreds of sea turtle projects and scientists focusing efforts in the region, no one had located hawksbills. Our findings help explain this… it's hard to spot hawksbills in mangrove estuaries."

Why?

Why the turtles were "seeking shelter" in mangroves was not clear. The scientists think it might be a recent adaptation brought on by a lack of their more typical habitat of coral reefs in the region.