Murray crayfish once thrived in the southern Murray-Darling Basin. The species was found everywhere from the headwaters of the Murray and Murrumbidgee Rivers in the Australian Alps all the way down to Wellington in South Australia.
For thousands of years, First Nations people managed harvesting sustainably. But crayfish stocks crashed after European settlement. This was partly due to commercial and recreational harvest, which began in the late 1860s. At its peak in 1955, 15 tonnes of Murray crayfish were taken from the river in New South Wales and sent to markets in Melbourne and Sydney.
In South Australia, the commercial fishery was unsustainable by the 1960s and the species was no longer targeted. In the 1980s, Murray crayfish became a protected species in the state. But the damage was done.
Over-harvesting was not the only problem. Murray crayfish prefer free-flowing, oxygen-rich water, so they suffered from efforts to regulate river flows using dams and weirs. Poor water quality, including pollution from pesticides and other agricultural chemicals, made matters worse.
Murray crayfish disappeared from South Australia sometime in the past 40 years. Targeted surveys over a five-year period couldn’t find them anywhere in the state.
But that all changed in the winter of 2023 when our reintroduction program began. Now we’re preparing for the third release of crayfish and there are positive signs many crays from earlier releases are still going strong.
A species in need of support
Like many species from the highly threatened Euastacus genus, Murray crayfish grow slowly. It takes almost ten years for a female to reach sexual maturity, and she only produces a small number of eggs. Dispersal is also limited. This makes it hard for the population to recover in both number and range.
Following a recent assessment, the species Euastacus armatus is expected to soon be listed as vulnerable to extinction under Australia’s conservation laws.
Conservation actions such as reintroductions will be necessary to aid recovery of the species.
A long time coming, shaped by adversity
The idea of returning Murray crayfish to the river in South Australia is not new.
Two University of Adelaide ecologists, the late Keith Walker and Mike Geddes, first suggested it in the 1990s. They even conducted trials involving crayfish in cages to show sections of the river would be suitable for the species.
Then in 2007, the reintroduction idea was floated again. It was one of the main recommendations in a report identifying gaps in knowledge of the species.
But the idea really gathered momentum after disaster struck. Widespread flooding across the southern Murray-Darling Basin in 2010–11 led to a “hypoxic blackwater” event. This is where leaf litter and debris from the floodplain wash into the river, depleting levels of oxygen and causing mass deaths of both fish and crayfish.
This inspired further research into crayfish genetics, recovery potential and preferred habitat. It guided a 2019 strategy outlining how the species could be successfully reintroduced. A trial five-year reintroduction program in the New South Wales range of the species helped refine the strategy.
Then another Murray blackwater event in 2022–23, in NSW and Victoria, forced crayfish out of the water and up the riverbanks.
Vision of dying crayfish leaving the water, only to be consumed by predators or poached by people, prompted the community to respond. Guided by fisheries agencies and a fishing conservation charity, they rescued crays and held them safely in aquaculture facilities until they could be released back into the wild.
Many of these crayfish were later returned to the river where they came from. But a small number were held for release into SA as part of our new reintroduction program.
In a truly collaborative effort, a small environmental not-for-profit organisation, Nature Glenelg Trust, worked in partnership with a natural resource management agency, First Nations community, fisheries agencies from three states and a private aquaculture facility to turn the idea into reality.
The team responsible for releasing Murray crayfish back into South Australia. Photo: Nick Whiterod
Positive signs from crayfish releases
Murray crayfish were first released back into South Australia in winter 2023. It was a big moment for people who have long championed the species’ return.
A further 200 crayfish were released during winter 2024.
During each release, some of the crayfish were tagged with trackers. This has provided world-first movement and activity information. It shows all tagged crayfish being regularly detected, indicating they are flourishing.
Field surveys each season at the reintroduction site have also found the species alive and well, representing the first Murray crayfish found in the state for more than 40 years.
Releasing a tagged Murray crayfish. Photo: Nick Whiterod
Returning a totemic and iconic species
The reintroduction of Murray crayfish into a closely guarded location in South Australia’s Riverland is both culturally and ecologically significant.
It signals the return of a important totem to the Erawirung people of the region, and provides a way to reconnect with the species.
Reestablishing a population of the species in South Australia, where hypoxic blackwater events have not been as severe, also provides insurance against extinction.
The species is considered a keystone species, meaning it plays a disproportionately large role in the ecosystem. So returning it to the river may have even greater ecological benefits.
Coauthor Sylvia Zukowski is managing the reintroduction program. Photo: Nick Whiterod.
The first of many steps
Reintroduction programs require ongoing commitment if they are to be successful. Extra crayfish will need to be added to the reintroduced population over the coming years.
The reintroduced population will continue to be monitored to ensure numbers are increasing and the range expanding. It will remain protected from fishing by local fisheries authorities.
If successful, further reintroductions may be undertaken into other parts of South Australia.
We had a thoroughly enjoyable final Skill Share Saturday for the year yesterday with Qigong, Fashion Upcycling, Seed Saving and Bushcare! We shared seeds from local gardens and harvested carrots, as well as Mizuna, Broad Bean, Daikon and Land Cress seeds from the Planetary Health garden. We then packaged up (and shared) our first Upper Mountains Seed Savers packs for our fledgling Seed Bank. In Bushcare it`s very exciting to see whole new areas of the Planetary Health Precinct open up as we remove invasive weeds. It`s been a year of great progress as we`ve restored habitat for wildlife and given local native plants the opportunity to flourish and re-establish on the site.
Join the Planetary Health Centre this Sat 6 Dec for the last Skill Share Saturday of the year: Qigong at 9am, Seed Saving & Gardening Group at 10am, and Bushcare at 1.30pm. One perfect day with great company, great coffee and food, and great steps for living a healthy balanced life, while also contributing to the health of our planet for present and future generations. All ages welcome!
Registration links in profile and below.
Register for Qigong here: https://bit.ly/48wlHjD Register for Seed Saving & Gardening here: https://bit.ly/4prcRe7 Register for Bushcare here: https://bit.ly/4oAFDrz
We have a rare opportunity to learn about the newest and best possible ways to support family and community members struggling with mental health issues, at a free talk and afternoon tea provided by Upper Blue Mountains Sunrise Rotary at the Planetary Health Centre at 2pm this Saturday 29 Nov. Hear from Peter Joseph AM, Chair of the Black Dog Institute, and Professor Helen Christensen AO, Fellow of the Australian Academy of Science and former Executive Director and Chief Scientist at the Black Dog Institute. They`ll be in conversation with journalist Emma Rossi. Dr Christensen is a pioneer in using the internet to reach young people struggling with depression. Her digital mental health interventions are used by millions globally, delivering evidence-based therapy for depression, anxiety, and suicide prevention. Her research uses data from smartphones and wearables – like movement, screen use, and sleep – to detect early signs of mental health issues. Bookings essential here (link in profile): https://bit.ly/4oOnYxz
This Saturday Sherlie McMillan from Rotarians 4 Planetary Health will be running a workshop on How to use a sewing machine from 9am at the Planetary Health Centre in Katoomba. Learn how to set up a machine, service it, troubleshoot when it`s not sewing correctly, and learn some basic sewing skills.
Bookings essential here (link in profile): https://events.humanitix.com/how-to-use-your-sewing-machine
NB. This class is a prerequisite for our very popular Fashion Upcycling classes held once a month.
We`re thrilled to announce that Professor Helen Christensen, a pioneer in using the internet to reach young people struggling with depression, will be joining the conversation with Peter Joseph AM from the Black Dog Institute and journalist Emma Rossi at the Planetary Health Centre at 2pm this Saturday 29 November. Helen was the Executive Director and Chief Scientist for the Black Dog Institute for 10 years and has now been elected a Fellow of the Australian Academy of Science. Her digital mental health interventions are used by millions globally, delivering evidence-based therapy for depression, anxiety, and suicide prevention. Her research uses data from smartphones and wearables – like movement, screen use, and sleep – to detect early signs of mental health issues. This free event is being co-hosted by Upper Blue Mountains Sunrise Rotary and the Blue Mountains Planetary Health Initiative. Afternoon tea will be provided. Bookings essential here (link in profile): https://bit.ly/4oOnYxz
Human composting is increasingly being legalised around the world. Read about it in Katoomba Area Local News here (link in profile): https://www.katoombalocalnews.com/legalising-human-composting/
If you’d like to see this option available in NSW you can now sign a live petition to the NSW Parliament here (link in profile): https://bit.ly/43QIHbz
Thanks to everyone who contributed to deliver a fantastic Disaster Risk Awareness Expo and Family Day yesterday. @mark_greenhill_mayor opened the event at which we celebrated the 13th birthday of Betty the Asbestos Education House; @firecoat_au demonstrated and launched its range of fire retardant products that can help protect homes, gardens and even electricity poles; the Bushfire Retrofit Toolkit was launched; Santa arrived and delighted young and old; and @plantinspired99 and Action for Animals fed us all with a delicious plant-based sausage sizzle. The day was filled with talks, workshops, stalls and the sharing of a huge amount of expertise to keep us, and the other species we share our planet with, safe and healthy! @southkatoomba.rfb @nswses @fireandrescuensw @nswrfs @redcrossleura @redcrossau @shelter.building.design @firehalo.au @asbestosawareness @amelie_ecology @bbagsbluemtns @wireswildliferescue @handsheartfeet
Our marquee is up and we`re excited about our Expo and Family Day tomorrow (Sat 22 Nov). There`s something for everyone from a free sausage sizzle, plants from Santa and drumming and pollinator workshops, to sessions on keeping you and our community safe from extreme weather events and hazardous substances like mould and asbestos. Learn how intumescent paints can slow the spread of fire and pick up a sample pot; check out all our emergency service organisations; learn how to dispose of hazardous materials; paint a native orchid, make some seed balls or sew a boomerang bag to give as plastic-free Christmas presents this year; enjoy coffee and locally made sweets; and get tips on how to retrofit your home safely and beautifully to be prepared for future extreme weather events. View the full program and register here (link in profile): https://bit.ly/4nFrY1J
There are so many new and innovative ways of doing things, like the new cooking techniques being explored by Michael from Good Fat Pastry, and the new fire protection methods being launched at the Planetary Health Centre`s Expo and Family Day on Sat 22 Nov. Check out Michael’s recent presentation at the Food Security Fair in our video here: https://bit.ly/4pnXbIg (link in profile) and come along to taste his delicious carrot cake and pastries at the Expo on Saturday. Check out the program and register to attend here (link in profile): https://bit.ly/4nFrY1J
In 2006 Peter Joseph’s son Michael suicided after a 14-year episodic battle with mental illness. Peter is now the Chair of the Black Dog Institute which is working to achieve better outcomes for all those struggling with mental health issues. Journalist Emma Rossi will engage Peter in an intimate and moving conversation about a life of purpose and mental health advocacy. As a Rotary scholar Peter will also reflect on how Rotary helped shape his values and sense of purpose as a young man - and how those early lessons continue to guide his work today. This free event is being hosted by the Upper Blue Mountains Sunrise Rotary Club and the Blue Mountains Planetary Health Initiative on Saturday 29 November from 2-4pm at the Planetary Health Centre at 33-39 Acacia St Katoomba. Afternoon tea will be provided. Bookings essential here (link in profile): https://bit.ly/4oOnYxz
Learn about intumescent fire retardant paint and a range of other strategies to prepare for extreme weather events, and to manage hazardous materials, at the upcoming Expo and Family Day at the Planetary Health Centre on Sat 22 Nov. You can register to attend here (link in profile): https://bit.ly/4nFrY1J We checked out how intumescent paint works in this video.
When temperatures reach a certain point the intumescent paint begins to swell and expand, often up to 50 times its original thickness. It forms a thick, carbonaceous "char" that acts as an insulating barrier. This layer slows the rate at which heat reaches the structural elements and buys valuable time for people to safely exit a building during a fire. It makes the structure safer for firefighters and rescue teams. #intumescentpaint #fireretardant #bushfire @firecoat_au...
Mould, lead paint, asbestos, silica dust from engineered stone bench tops and a wide range of chemicals, are amongst some of the many hazardous substances entering our environment and negatively impacting our health. Asbestos is found in over 3000 products including textured paints, moulded garden pots, brake pads and clutch linings in older cars, floor and ceiling tiles, lino, fibro, roofing, pipes and gutters, hot water systems, backing for switchboards and insulation boards in air-conditioning ducts, insulation, sealants, fillers, caulking and adhesives, gaskets for industrial and lab equipment and more. We’ll have information to take away and Blue Mountains City Council and the Asbestos and Hazardous Materials Consultants Association (AHCA) will be running free workshops on how to identify and manage these hazardous substances at the Planetary Health Centre`s Disaster Risk Awareness Expo in Katoomba on Sat 22 Nov. Find out more and register to attend here (link in profile): https://bit.ly/4nFrY1J
Blue Mountains Planetary Health Centre will host the Disaster Risk Awareness Expo and Family Day on Saturday, 22 November, offering a fun and informative day focused on building safer, healthier and more resilient communities.
