Saving the Fitzroy Falls Spiny Crayfish

Awakened from a daytime slumber by the very appealing smell of pilchards, a female crayfish creeps out of her creek bed burrow into our net.

She's one of just a handful of Fitzroy Falls Spiny Crayfish (Euastacus dharawalus), the rarest native crayfish in New South Wales, living in a 12km stretch of creek at Fitzroy Falls in the Southern Highlands. And illegally removing her or her mates from their gum tree-lined creek can land you in jail for two years and leave you with a $220,000 fine.

The Fitzroy Falls Spiny Crayfish has joined the Northern Hairy-nosed Wombat and the Southern Bluefin Tuna on the International Union for Conservation of Nature Red List of 87 native animals that are critically endangered - meaning they are facing an extremely high risk of extinction in the immediate future.

UOW Biology Honours student Katie Hendry is on a mission to save these critically endangered critters. But first, she needs to know more about them.

The mostly shy but sometimes aggressive little creatures can live up to 30 years, but are under threat from introduced yabbies, which compete for food and shelter; illegal fishing and habitat degradation from polluted farming runoff; and clearing and construction of the Fitzroy Falls Reservoir, which supplies water to the Southern Highlands and Shoalhaven regions and at times, Sydney.

"Getting to know them has been really interesting," says Katie. "They can be really aggressive. If I approach them, they'll raise their chelipeds [claws] quite high at me. But the yabby, the invasive species, I would consider them like that chilled out guy at uni. They just don't really care you're there.

"The yabbies have even been so bold as to tap on the glass in their individual holding tanks to ask to be fed. Whereas the crayfish are always very angry to see me."

Passionate about conservation

For the past few months, Katie, a Bowral-local, has been visiting the area around Wildes Meadow Creek in search of the crayfish. It's potato-farming country, about 6km downstream from Fitzroy Falls' stunning 80m-high waterfall and only 20 minutes drive to the country gardens and tulips fields of Bowral, a mecca for wealthy Sydney retirees and foodies. But there's one crustacean you won't find on local menus.

As part of her project, Katie has collected 10 Spiny Crayfish and 10 invasive Common Yabbies (which are native to Australia, but not found east of the Great Dividing Range, until their introduction to the area around ten years ago), shipped them back to her UOW lab and started behavioural trials on both species - to see how they interact with each other and how they compete for food and shelter. She's the only researcher actively studying these critters at the moment.

"There's so much we don't know about them," Katie muses. "I started working on this project because I am really passionate about conservation. I fell in love with on-the-ground research - getting out there and making a difference. That's where I see myself being for the rest of my life - whether it's in a job or doing it as my hobby. That's where I'm happiest, that's where I'm most fulfilled."

Katie says she's grateful to be doing such meaningful and important work, particularly as an honours student.

"Crayfish are important members of any ecological community. They are often used as indicators for water quality as they help break down organic matter in waterways…If they were to become extinct, there would most certainly be flow on impacts to other species living within the ecosystem."

Katie says her experience at UOW has been "absolutely fantastic".

"I've found UOW to be a fantastic community with lots of support and so many amazing supervisors. You have world-renowned researchers at your fingertips who you can just pop in on and ask advice from or just have a chat about different animal behaviours and they can draw on their experiences and advise you to go in a certain direction. There's no other platform where that's possible."

"The Fitzroy Falls Spiny Crayfish has joined the Northern Hairy-nosed Wombat and the Southern Bluefin Tuna on the list of 87 native animals that are critically endangered."

Help needed from locals and citizen scientists

Katie is hoping her research will pique the interest of locals, who have a role to play in saving the crayfish.

"People don't really know about these critically endangered species are living on their doorstep. They're going out yabbying with their family and possibly eating the critically endangered species by mistake."

Katie said before she started the project she, as an ecologist, didn't even know about the crayfish. "It was a huge surprise to me. I think if locals know there is an amazing freshwater species so close to home, they will really come on board and help us protect them, help us rehabilitate the creek lines."

Since the construction on the Fitzroy Falls reservoir was completed in 1974, there are now two populations of the species isolated from each other - one below the dam wall and one upstream of the reservoir, of which 1km of habitat is protected as part of Morton National Park. Only 750m of habitat below the dam wall (which is largely agricultural land) is now considered high quality for the slow-growing crayfish, which take up to seven years to mature.

"I'm hoping my research will help close some key knowledge gaps. For example, where we should be focusing our efforts to help protect the crayfish. Should we focus on rehabilitating polluted creek lines? Or should we concentrate on eradicating yabbies, which are only native in NSW to places west of the Great Dividing Range?"

"I started working on this project because I am really passionate about conservation. I fell in love with on-the-ground research – getting out there and making a difference. That’s where I see myself being for the rest of my life – whether it’s in a job or doing it as my hobby." – Katie Hendry

Katie's research is supported by the NSW Department of Primary Industries Fisheries Scientific Committee.