Smooth Marron Populations
While past translocations of Smooth Marron (Cherax cainii) have resulted in an expansion of its distribution northward and eastward, there has also been a decline in its inland range and local abundances due to water quality decline and loss of habitat. The populations have deteriorated over the past 40 years. Monitoring of the recreational Smooth Marron fishery since the mid-1970s has shown both a reduction in total catches and a reduction in catch rates. There is some recent evidence of stabilisation.
Calls to action:
- The long-term sustainability of the species will depend on careful monitoring of fisheries stocks and addressing the many threats that south-western Australian rivers face. These include efforts to address the major issue of secondary salinisation of waterways and protecting and rehabilitating riparian zones. The species should also be considered during surface and groundwater resource extractions as it relies on surface water refuge. Novel management actions such as captive breeding for re-stocking certain dams are also being investigated. The threat posed by illegal poaching and the possibility of additional large predatory fishes being introduced should also be considered.
- The social, ecological and economic value of this iconic invertebrate makes it an ideal indicator species.
- Beatty S.J., De Graaf M., Duffy R., Nguyen V., Molony B. (2016). Plasticity in reproductive biology of the large freshwater crayfish Cherax cainii (Decapoda: Parastacidae) in south-western Australia. Fisheries Research 177: 128-136.
- De Graaf, M., Beatty, S. and Molony, B.M. (2010). Evaluation of the recreational marron fishery against environmental change and human interaction. Baxter, D. and Larsen, R. (editors) Final report to Fisheries Research and Development Corporation on Project No. 2003/027. Fisheries Research Report No. 211. Department of Fisheries, Western Australia. 188pp.
- Duffy, R., Trinnie, F., Ryan, K., Yerman, M. (2018). South-west recreational freshwater resource status report 2017. In: Status Reports of the Fisheries and Aquatic Resources of Western Australia 2016/17: The State of the Fisheries eds. D.J. Gaughan and K. Santoro. Department of Primary Industries and Regional Development, Western Australia. pp. 36-40.