‘Spectacular’ spiny crayfish samples rec amid Lismore floods key to mapping species
As floods devastated Lismore, a group of ecologists waited anxiously for a break in the weather so they could move an important scientific collection of “spectacular” spiny crayfish to a new home at the Australian Museum.
The samples of the crayfish were collected more than 20 years ago from deep within the rainforests of north-eastern NSW and southern Queensland by Dr Jason Coughran, a freshwater ecologist.
Prof Nigel Andrew, the chair of science at Southern Cross University, said the collection of multiple species was a “valuable biological resource” helping scientists to understand and conserve the animals, which are highly susceptible to climate change.
Years of discussions between the university and the Australian Museum had culminated in a plan for museum staff to collect the samples in Lismore on 1 March last year. But just days before they were due to arrive, unprecedented floods devastated the region.
While the university’s Lismore campus never flooded, the museum team faced a nervous wait as they assessed the risk to the collection and of heading into the flood zone.
Nearly two months later, on 26 April, it was deemed safe for the team to gather the collection and transfer it to the museum in Sydney.
Prof Shane Ahyong, the head of marine invertebrates at the Australian Museum, said another week later the site again became inaccessible because of more flooding.
“The floods continued to get worse and the disaster was in full train. So it was very serendipitous that we were able to get in just in time,” he said.
Ahyong said spiny crayfish need pristine water to survive, unlike their inland cousin the yabby, which can tolerate poor water conditions.
He said the crayfish have thorny armour – “like little battle tanks” – to protect them against predators, but they are susceptible to habitat change, whether from land clearing or natural disasters.
“These can be quite large, spectacular animals,” he said, adding that they are also very diverse.
“They only have very narrow distributions, so each river catchment down the coast basically has its own species.”
Half of all spiny crayfish species in Australia were affected by the black summer bushfires, and efforts to protect the remaining populations are at risk from further natural disasters and climate change.
The scientific collection, gathered in remote and hard-to-reach areas, enables scientists to make more accurate distribution maps of the animals as they continue to assess the affect of the fires, Ahyong said.
Survey work stemming from the bushfires led to the discovery of 20 new species of spiny crayfish, in addition to the 54 known species. Many of these species are endangered.
“These reference samples make a big difference, because we need to be able to study their anatomy precisely when we discover a new species and distinguish them from the known species,” Ahyong said.
“Every specimen that we have increases the accuracy of the work.”
Erich Wittstock, a laboratory team leader at Southern Cross University, said the donation of the collection to the Australian Museum meant the museum’s taxonomists could properly preserve specimens for the future.
“Without this endeavour, the collection would have been lost,” Wittstock said.