Scientists have discovered Australia’s most critically endangered cray, the Fitzroy Falls spiny crayfish, in new territory in the NSW Southern Highlands.
The species was previously only found along a 9-kilometre stretch of Wildes Meadow Creek which feeds Fitzroy Falls, hence the name.
Research by the NSW Department of Climate Change, Energy, the Environment and Water, was investigating the abundance, size and sex ratio of freshwater spiny crayfish above and below the Nepean, Avon, Cordeaux, Cataract, and Woronora Dams.
Using simple traps, they would safely catch, weigh, measure and then release the crayfish back into the water.
To their surprise, the incredibly rare species was found in the headwaters of the Nepean and Wingecarribee Rivers and some of the rivers’ tributaries – a 30-kilometre expansion to their previously known range.
The Fitzroy Falls spiny crayfish population in Wildes Meadow Creek was under serious threat in recent decades, due to habitat loss and modification, competition with the invasive common yabby, being mistaken for the common yabby by fishermen and predation from introduced species including foxes, cats and non-native salmonids (such as introduced trout).
However, a recent program run by Local Land Services has improved and protected riparian habitat, created community awareness of the species and conducted introduced species control efforts in Wildes Meadow Creek.
Small but mighty, crayfish are important members of the freshwater ecosystem and important indicators of catchment health. They play a pivotal role in processing organic matter by shredding materials on the riverbed, aerating soil on the banks through burrowing and providing a primary food source of food for frogs, fish, invertebrates, and platypus.
This discovery of this healthy population identifies this region of Nepean catchment as a critical stronghold for the Fitzroy Falls spiny crayfish.
A current research project led by the University of Wollongong will continue to assess the species’ long-term requirements for persistence. The department, in collaboration with WaterNSW and NSW DPIRD, will apply these findings to manage habitat and flow, ensuring the species’ survival into the future.
Quotes attributable to Executive Director Water Planning and Knowledge Mitchell Isaacs
“This is incredibly encouraging news for one of Australia’s most endangered freshwater species.
“Healthy crayfish populations are a key indicator of clean, functioning waterways, so this is good news not just for the species, but for the entire catchment.
“The health of our waterways is evident in the species that call them home, and this discovery is a strong sign that parts of the Southern Highlands catchment are thriving.”
