Photo by Nat Geo Explorer in Residence enricsala | Cocos Island, off Costa Rica, is a key stop for green turtles moving across the eastern tropical Pacific. They are often bycatch in tuna fisheries, but the expanded 54,000-square-kilometer Cocos Island National Park provides some refuge to this threatened species. This photo was taken during a Pristine Seas expedition in October 2009. Supported by the National Geographic Society, Pristine Seas works to protect the world's oceans by creating or expanding marine protected areas. #WorldSeaTurtleDay natgeopristineseas insidenatgeo