Raine Island - Turtle heaven or turtle hell?

This is an extract from the eatlas book Natural history and research and management of Raine Island's green turtle rookery.

Green turtles Raine Island

Raine Island on the northern Great Barrier Reef is identified as the largest rookery in the world for the green turtle (Chelonia mydas) with upwards of 15 000 females having been recorded attempting to nest at the one time along the approximately 1.8km of beach. During high density nesting seasons turtles can become so concentrated in some areas that successful nesting is all but impossible.

© courtesy Qld Govt

Raine Island, a 27.5 hectare cay situated on a detached reef and located in the far northern Great Barrier Reef is, along with the adjacent Moulter Cay, the focus of approximately 90% of all nesting effort of the Northern Great Barrier Reef (NGBR) green turtle genetic stock. The small sand cay is the largest rookery in the world for the green turtle (Chelonia mydas) with upwards of 15 000 females having been recorded attempting to nest at the one time along the approximately 1.8km of beach.

Green turtles die on Raine Island

Turtle overturned after falling from rock that surrounds the island

© courtesy Qld Govt

This incredible display of life easily leads the casual observer to believe that this is one of the great sea turtle rookeries of the world producing masses of offspring for future generations. However through ongoing research and monitoring it is becoming apparent that this may not be the case and that in fact Raine Island may be destroying rather than creating future turtle populations.

Every year from late October to February egg laden females arrive, having migrated from many parts of northern Australia, eastern Indonesia, Papua New Guinea and as far away as Vanuatu and New Caledonia (a migration of over 2700km) crawl up the beach at night and attempt to lay their approximately 100 eggs. They are generally expected do this 4-6 times in a nesting season and then not return again for the next two to six years.

Recent monitoring and research at the island indicates that successful incubation rates of green turtle nests is well below what might be expected for this location (QPWS internal report 2013). This is believed to be leading to low recruitment back to inshore feeding areas and combined with other pressures on the population may see numbers plummet in the coming decades. There is real concern that Raine Island's future as a centrepiece of the Great Barrier Reef's World Heritage listing is in doubt.

A 'Prospectus' was recently released by the Queensland Government seeking a major sponsor to support direct management action on Raine Island. A short 'YouTube' video narrated by Sir David Attenborough highlights the issues and asks for help. Read the full story about Raine Island here.