News & Events

WRM discover the introduced Redclaw crayfish (Cherax quadricarinatus) in Karijini National Park

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. This was a surprising and significant discovery, as no crayfish species occur naturally in the Pilbara, meaning these Redclaw were introduced by human hands. Although Redclaw have been previously recorded from the Harding Dam near Karratha, this is the first record from a ‘natural’ Pilbara ecosystem, and unfortunately is from one of Western Australia’s most well-known national parks no less!

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. The introduction of Redclaw to natural ecosystems in the Pilbara has 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.

However, not all is lost! WRM consultants Fintan Angel and Emma Thillainath are currently (August 2016) assisting the Western Australian Department of Parks and Wildlife (DPaW) conduct 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. It is hoped that if the infestation is not too widespread, eradication, or at least some level of population control will still be possible.

Stay tuned for further updates about the invasive Redclaw crayfish in the Pilbara region.

Close-up of the invasive Redclaw crayfish (Cherax quadricarinatus), first recorded by WRM consultants in a gorge system in Karijini National Park in March 2016.