The Waanyi people of the Gulf of Carpentaria have long known of the existence of endangered Gulf Snapping Turtle, but it was unknown to science until 1986 when it was 'discovered' as a 25,000 year old fossil at Riversleigh Fossil fields of Queensland.
It's formed an important food source and been part of Waanyi culture for thousands of years. Today the turtle is known to occur in the spring-fed upper reaches of the Nicholson, Gregory, Calvert and Robinsons Rivers in the Gulf of Carpentaria, where it lives in deep permanent water pools.
It has a close association with Cluster Fig Trees, which occur along the river banks. It uses the roots of these trees for refuge and the abundant fruits and leaves provide an important food source.
This Commonwealth-listed, endangered species was one of the significant finds during Bush Heritage’s joint recent survey and culture camp with Waanyi Garawa Rangers and Traditional owners in the Ganalanga-Mindinbirrina Indigenous Protected Area (IPA).
This is the third year that Bush Heritage Australia, the Waanyi Garawa Rangers and Northern Land Council have worked with Traditional Owners to survey the plants and animals of the IPA. This year’s camp was hosted by the Hogan family at their Murun Murula Homeland on Waanyi country in the south of the IPA.
This year’s recording of the Gulf Snapping Turtle represents the most southerly record in the Northern Territory.
It was the second year we've recorded the species on the IPA. Covering nearly 10,000 square kilometres and taking in much of the catchment of the Nicholson River, the IPA represents a large proportion of the known range of this endangered species.
Threats to the turtle include destruction of riverside habitat and nests by pigs and fire.
The Waanyi Garawa Rangers and Traditional Owners of the IPA have established a comprehensive fire management program to help reduce the frequency of large, destructive, late-dry-season fires. They've also recently embarked on a program to map the distribution of feral pigs to enable better targeting of pig control efforts.
Another significant species recorded during this year’s survey was the beautiful Purple-crowned Fairy Wren. This bird is in decline in the west of its range in the Kimberley and Victoria River regions, but appears to have healthy populations in the Gulf and we recorded it in most riparian sites during surveys on the IPA. It, too, relies on riverside vegetation for its survival and the management by the Waanyi Garawa Rangers is helping to secure its future.
Another exciting find was a species of Purple-spotted Gudgeon captured by ranger Clinton Daylight, which he caught by hand turning over the leaves and debris they hide under near the water edge. Despite having fish sampling equipment provided by the Northern Territory Museum it was Clinton's traditional knowledge and skills that allowed us to find this species.
Fish expert Dr Mike Hammer explained the significance of this: “The Northern Purple-spotted Gudgeon appears to be a complex of lots of different species, and the Gulf region is very interesting, having links to the inland Barkly tableland, the Top End and Cape York – this may be a unique local species or several species!”
We captured seven species of fish during the surveys. These are important records because as Mike explained: “The samples from Murun Murula are from a very remote area with no previous fish records, and they help fill a key information gap to help solve the mystery of how many species there are in the group, and what shapes fish distribution patterns in the landscape”.
Bush Heritage would like to acknowledge and thank the Waanyi Traditional Owners of Murun Murula, and particularly the Hogan family for their support and help with this year’s survey camp.
Unfortunately senior owner, Jack Hogan got sick just before the surveys but we're grateful for his enthusiastic support and happy to hear he's recovering well. Gavin, Noel, Jake and Nicole Hogan all provided valuable support and direction during the surveys. We'd also like to thank the Waanyi Garawa Rangers and Northern Land Council staff for their support and help. We also thank botanist Kym Brennan for coming along as a volunteer to help with logistics.