Research highlights plight of freshwater crayfish 

Mark Schultz will be awarded a PhD from Charles Darwin University for his ground-breaking research to uncover the evolutionary history of freshwater crayfish.

Freshwater crayfish are important elements of aquatic communities and are highly threatened by human impacts, but little is known of their evolutionary history despite this information being necessary for the conservation of any species. 

Mark Schultz, who will be awarded a PhD from Charles Darwin University at this week’s end-of-year graduation ceremony, has spent the last four years working on a research project to uncover the evolutionary history of freshwater crayfish.

“The centre of diversity for the southern hemisphere crayfishes is southeastern Australia - a region with a high urban population and rural development, and one considered critical to the survival of the species,” Mr Schultz said.

The research project aimed to recover the evolutionary history of a select group of Australia’s threatened freshwater crayfishes from southeastern, southwestern and eastern Australia using cutting-edge DNA sequencing, bioinformatics and Geographical Information Systems technologies.

Mr Schultz’s research allowed him to determine regions of future conservation significance by gaining an informed look into the past. 

“Five new species and one new genus of freshwater crayfish were discovered, making southeastern Australia a centre of freshwater crayfish diversity that is unrivalled anywhere in the world,” he said.

“Present day freshwater crayfish distributions are likely the result of drying of the continent 25 million years ago and an increase in sea-level through Bass Strait.”

Mr Schultz believes that the Grampians and Otways mountains in Victoria have provided critical habitats during the history of these species and will likely be important refuges into the future.

“I feel that it is a real honour to be graduating with a PhD in evolutionary biology at CDU in the year of the three Charles Darwin anniversaries,” he said.

“That is, 2009 is the year of Charles Darwin’s 200th birthday, it is the 150th year since publication of On the Origin of Species, and the 170th year since the Beagle visited the Top End and Darwin’s former shipmates named Port Darwin in his honour”.