News & Events
25/09/19 – Research paper on the spread of redclaw crayfish published
WRM’s principal ecologist Adam Harman, in collaboration with Dr Adrian Pinder from the Western Australian Department of Biodiversity, Conservation and Attractions (DBCA), and with support from Fortescue Metals Group (FMG), recently had their research paper “Spread of redclaw crayfish into Pilbara natural waters” accepted for publication in the journal Bioinvasions Records.
Way back in March 2016, WRM field scientists observed redclaw crayfish (Cherax quadricarinatus) in a gorge system in Karijini National Park, in the Pilbara region of Western Australia (the first record from a ‘natural’ Pilbara ecosystem), and in August 2016, WRM’s Fintan Angel and Emma Thillainath (also co-authors of the paper) joined Dr Pinder in conducting surveys of additional gorges in Karijini National Park (as well as other locations across the Pilbara), in an attempt to uncover the extent of the “Redclaw problem” in the region. Redclaw crayfish are considered pest species outside of their natural range (Tropical North Queensland & the Northern Territory), as they are tolerant of a broad range of environmental conditions and have a simple reproductive cycle with fast growth rates. They have been introduced to waterways in all Australian States (except Tasmania) as well as overseas, damaging ecosystems through modification of natural habitats, direct predation, competition with native species and the spread of crayfish pathogens and diseases. At the time it was presumed that the introduction of redclaw to natural ecosystems in the Pilbara would have the potential to be similarly damaging, especially considering aquatic communities of the region have evolved over millions of years without the presence of freshwater crayfish. This new paper sheds some new light on the issue.
Spread of redclaw crayfish into Pilbara natural waters describes the current distribution of redclaw across the Pilbara region, which includes the aforementioned Karijini National Park, as well as Millstream-Chichester National Park, Weelumurra Creek (a small tributary of the Fortescue River), and anecdotal records from Harding Dam (Karratha) and Ophthalmia Dam (Newman). It also provides some interesting information on the effects of redclaw on Pilbara creek ecosystems, with an ecological survey on Weelumurra Creek suggesting that redclaw presence is associated with significant reorganisation of faunal and floral assemblages of pools – namely, the loss of aquatic vegetation, snails and microinverterbates (zooplankton) – as well as advice on redclaw management in the Pilbara, which is a tough task given the remoteness of the region!
Congratulations to Adam, Dr Pinder and the rest of the authors for writing and publishing such a great (and important) paper, and special thanks to both DBCA and FMG for providing funding and collaborative support. You can find the paper here.