Team rescues threatened sawfish pups from remote billabong

Indigenous rangers and Charles Darwin University researchers spent five days trudging barefoot in mud to save almost 40 largetooth sawfish pups as their nursery dried out on the edge of floodplains near the Daly River, 220 km southwest of Darwin.

Malak Malak Rangers discovered the sawfish trapped in a small waterhole in a channel off Tyumalagun (meaning shark swamp) about an hour’s drive from Naiuyu Community.

CDU senior research fellow Dr Peter Kyne and research associate Brittany Finucci helped conduct the major rescue mission, with 38 juveniles successfully caught by hand and released into the Daly River, as part of a national threatened species management project.

“The core area where the sawfish were found was a muddy hole with water only 10 to 20cm deep,” Dr Kyne said. 

“In total we caught 39 pups in the waterhole; one died in transit. We also found 16 that had already died in another area.”

Dr Kyne said the rescue was a significant boost for the critically endangered species, which is thought to be extinct in almost 30 countries, with Northern Australia and Papua New Guinea the last major population strongholds anywhere in the world. 

The project, titled “Northern Australian hotspots for the recovery of threatened euryhaline species”, concentrates on large rivers and estuaries of the Top End, including the Daly and Adelaide rivers in the Northern Territory.

The project is supported through the National Environmental Science Program’s Marine Biodiversity Hub, with research undertaken in the Daly River region since 2012.

Dr Kyne said Malak Malak Rangers patrolled for trapped sawfish as water levels receded at the end of each dry season, with a purpose-built fish tank on the back of a ute to assist with safe relocation to the river.

The rescued fish, all aged just under 12 months and measuring between 1.1 and 1.2 metres, were tagged for future monitoring, and tissue samples were taken for genetic studies.