
CULVERTS FOR WILDLIFE PROJECT
(formerly the Giant Freshwater Crayfish Project)
This project idea was inspired by Kentish Councillor (and former Mayor) Don Thwaites, who on several occasions has observed giant freshwater crayfish walking across Union Bridge Road in the Minnow Catchment.
​
The Giant Freshwater Crayfish (Astacopsis gouldi) is the largest freshwater crayfish in the world, and is found only in rivers in the north of Tasmania. It is listed as an endangered species on the IUCN Red List due to overfishing and habitat degradation, and it has been prohibited to catch the crayfish since 1998. The crayfish move up and down streams for feeding and breeding, but it appears in this case that they are unable to use an under road culvert, and instead are getting out of the stream and crossing the road, to get to the stream on the other side of the road. Don has also observed platypus road kill in the same area.
​
In 2021 funding was obtained from Landcare Tasmania to engage a contractor to survey priority under road culverts in the Kentish Municipality to determine whether or not they are accessible to crayfish. MRLC has been fortunate to contract Todd Walsh, a global authority on crayfish, to carry out this work.
​
Todd visited the area in late February 2022 and - with the help of MRLC volunteers - established trial solutions at several culverts, and these were subsequently monitored to see whether or not they were effective. The results in this phase of the project were not conclusive, but did provide us with many learnings and subsequently a new range of trials to implement. Importantly, through our discussions about this project, we came to realise that it was not only crayfish that were having difficulty negotiating under road culverts. A range of other aquatic/semi-aquatic creatures, including platypus, were likely to face the same challenges, so we decided to broaden the study to consider the requirements of these creatures too, where possible.
​
Todd Walsh was again in Kentish in March 2024 and visited several culverts with members of MRLC and the Kentish Council. Several trial sites and a range of solutions were identified. We also consulted with Sustainable Timbers Tasmania, Forico, Cradle Coast NRM, NRM North, and the Dept of State Growth to gain their thoughts on project methodology.
On Saturday 4 May, Todd spoke at the "New Life" event at Claude Road Hall. View flier here. As part of Todd's talk he showed the audience a live adult and juvenile crayfish (Todd returned both to their homes after the event!). ​
​
Excitingly, in Nov 2024 MRLC was successful in obtaining a highly-competitive grant from Landcare Australia to continue this project. The grant - worth $10 476 - will be trialling various culvert modifications at four sites in the Mount Roland area from December 2024. Todd Walsh will lead the project which involves micro-chipping crayfish to track their ability to negotiate culverts. We will be using new technology to scan the microchips as the crayfish travel. A report will be produced by the end of July 2025 which will recommend ways to remediate existing culverts as well as providing best practice guidelines for the installation of new culverts. Todd begins the preliminary work of catching, microchipping, and releasing crayfish at the trial sites on Monday 16 Dec.
​
More information to come soon.
​
​
​
​This project has been made possible by initial grant funding from Landcare Tasmania of $3,500; a positive and cooperative working relationship with the Kentish Council; the voluntary input of MRLC members; support from local land-owners; and the grant from Landcare Australia mentioned above.
​​​
​
​