New satellite tracking has confirmed that critically endangered hawksbill turtles use the Coral Sea as their highway to travel from Papua New Guinea to the Great Barrier Reef.
It adds to mounting concern over the federal government’s draft plans to reduce the Coral Sea’s protected areas by 50%.
The satellite tracking information is part of the “Bring Back the Bills (PDF 1.8MB)” project* to arrest the alarming decline of hawksbills across the Indo-Pacific region.
Millions of hawksbills were killed for their shells, prior to a worldwide ban on the tortoiseshell trade, and the species has never properly recovered.
The northern Great Barrier Reef lagoon was thought to have one of the few remaining large populations but it is endangered and slowly declining.
Anecdotal evidence suggests PNG’s hawksbill numbers are also in decline.
A research trip to the Conflict Group of Islands (29/12/2017 – 12/1/2018) aimed to learn more about PNG’s hawksbills and their relationship to the north-east Australian stock.
The expedition was a partnership between WWF-Australia, the University of the Sunshine Coast (USC), local Milne Bay Province community turtle monitors and the newly established Conflict Island Conservation Initiative (CICI).
Satellite trackers were attached to 10 hawksbills nesting in the Conflict Group of Islands, to discover their migration paths and location of their foraging grounds.
Genetic samples were taken and these will be analysed in coming months to learn if the PNG and NE Australian stocks are related.
Christine Hof, WWF-Australia’s marine scientist and USC’s PhD researcher, said hawksbills are a protected species in Australia but not PNG.
“Hawksbills must be afforded protection across borders at their nesting beaches and feeding grounds, and along their entire migratory path if they are to recover,” Ms Hof said.
It was hoped that because of its remoteness, the Conflict Group of Islands could be a stronghold for hawksbills.
But monitoring by CICI showed that from 2 November to 10 January, of the 352 turtles that attempted to nest in the Conflict Group of Islands, only 33 (fewer than 10%) were hawksbills.
In this isolated region, turtles and their eggs have long been harvested for food and to trade for other items. It’s also feared the shell ends up in the black-market tortoiseshell trade.
CICI turtle monitors rescued four hawksbills from poachers in December.
The Conflict Group of Islands are owned by Australian millionaire Ian Gowrie-Smith.
“My aim is to garner the cooperation of the local communities by way of education, illustration and financial income alternatives to become an iconic illustration of what community-based conservation can achieve,” Mr Gowrie-Smith said.
“I recognise the enormous ecological importance of the islands and wish to preserve it for all our future generations,” he said.
Apart from poaching of turtles and their eggs, threats include capture in fishing gear, marine debris, and climate change impacts.
Sea level rise, caused by climate change, can make nesting beaches inaccessible or can drown eggs.
Climate change can also harm foraging habitat and make sand so hot that nests fatally overheat.
Tree trunks – thought to drift around PNG waters from local harvesting or logging activity – also wash ashore and block turtles attempting to nest.
This season, CICI said turtles struggled with some beaches badly eroded by strong trade winds. Then a nearby cyclone whipped up large waves which destroyed many nests on Panasesa and Irai Islands.
*Collaborative project partners of the Bring Back the Bills project include WWF-Australia, USC, local Milne Bay community turtle monitors, CICI, and its volunteers.
The field trip and satellite trackers were supported by WWF-Australia, Isaacson Davis Foundation, USC and Reef HQ Aquarium Turtle Hospital.