for National Geographic News
This story is one of a series looking at National Geographic Crittercam research. Crittercam is a research instrument worn by wild animals and equipped with a video camera and other information-gathering equipment. (Get the basics on underwater and terrestrial Crittercams.)
Sea turtles around the world are on a slippery slope toward extinction, but in Shark Bay, on the remote coast of Western Australia, two species of the ocean-dwelling reptiles thrive among a flourishing diversity of life.
"Shark Bay gives us a glimpse of what other marine habitats might have been like before they were changed by people," said Mike Heithaus, a marine biologist at Florida International University in Miami.
He and other researchers are learning why why Shark Bay is a flourishing ecosystem. They hope their findings can help with conservation efforts in stressed parts of the world's oceans, where the larger animals are losing the battle to survive.
In Shark Bay loggerhead and green sea turtles graze and swim among vibrant beds of sea grass with dugongs, bottlenose dolphins, and six species of sea snakes.
As the name of the bay suggests, tiger sharks (Galeocerdo cuvier) lurk nearby, waiting for opportune times to attack. Many loggerheads, in particular, bear wounds from narrowly escaping the jaws of death.
Since 1997 Heithaus has studied how the major marine species in Shark Bay interact. His work is part of an ongoing project initiated by Larry Dill, a marine biologist and Heithaus's former advisor at Simon Fraser University in British Columbia, Canada.
Understanding how the sea grass ecosystem functions in Shark Bay may help rehabilitation efforts in more impacted areas, such as the United States' Florida Bay in the U.S. and parts of the Caribbean, Dill said.
"Many habitats have been destroyed, but at some sites people are interested in trying to restore them," Dill said. "But we don't have many examples of functional sea grass ecosystems to use as a baseline. Shark Bay happens to be in good shape."
In years past the researchers have studied the bay's tiger sharks, dolphins, dugongs, and sea snakes. They've now turned their attention to the sea turtles to help round out the picture, Heithaus said.
One of their biggest questions is why the loggerheads bear so many wounds from tiger shark attacks but the greens appear relatively unscathed. National Geographic sent the Crittercam team to Shark Bay to help the researchers find answers.