Glenelg Spiny Crayfish

Condition monitoring and genetics assessment of Glenelg Spiny Crayfish

Monitoring by Aquasave – NGT, commissioned by the Friends of Mount Gambier Area Parks, in 2011 highlighted some concerns for the South Australian population of Glenelg Spiny Crayfish (Euastacus bispinosus) (see Glenelg Spiny Crayfish monitoring). Low numbers, limited recruitment and high percentage of individuals with gonopore aberrations across most sub-populations, as well as a declining trend in the condition of rising-spring aquatic and bank habitat (between 2006 to 2011) justify the species being currently considered ‘Critically Endangered’ in South Australia. Encouragingly, restoration efforts have begun in several locations across the range of the species, with work being conducted by the Friends of Mount Gambier Area Parks and South Australian Department of Environment, Water and Natural Resources (DEWNR).

Glenelg Spiny Crayfish (Dave Mossop)

Building on this previous work, Aquasave – NGT is actively involved in ongoing condition monitoring of the SA population and a broader genetic study. The results of the 2011 monitoring – namely, low numbers and a high percentage of aberrant individuals, coupled with isolation and the limited dispersal ability of the species – suggests genetic vulnerability amongst the SA population. In response to these findings, it was decided that a genetic investigation of the species was warranted, and this has now received funding. The Friends of Mt Gambier Area Parks have been awarded a DEWNR State NRM Community Grant and Nature Glenelg Trust was awarded a Norman Wettenhall Foundation grant, which together will provide sufficient funding to enable the genetic structure of the species to be assessed. The genetics study is a collaboration between Oisín Sweeney (DEWNR), Adam Miller (CESAR – Melbourne University) and Nick Whiterod (Aquasave – NGT).

The genetics study involved lots of sampling across South Australia and Victoria and found some worrying results. In particular, it is evident that South Australian populations of the species exhibit critically low genetic diversity and were highly structured with limited gene flow between locations and catchments (e.g. isolated populations). We have continued condition monitoring  through 2012 (through Friends of Mt Gambier Area Parks grant) and 2013  (through DEWNR) to assess trends in the status of key sub-populations and investigate gaps across the SA range.

In summary, the species persists in the previously identified locations (e.g. Ewens Ponds, Deep Creek) and populations were identified in two isolated sinkholes. However, numbers are patchy and given the genetic outcomes, the species extremely vulnerable to localised habitat degradation and extinction of isolated populations is conceivable in the future. Coordinated conservation efforts must continue to help conserve the species!

For more details

Miller A.D., Sweeney O.F., Whiterod N.S, Van Rooyen A., Hammer M., Weeks A.R. (in review). Highly fragmented populations of the endangered Glenelg spiny freshwater crayfish (Euastacus bispinosus) exhibit critically low levels of genetic diversity.  Submitted to Endangered Species Research.

Miller A. D., Van Rooyen A., Sweeney O.F., Whiterod N.S., Weeks A.R. (2013). The development of 10 novel polymorphic microsatellite markers through next generation sequencing and a preliminary genetic analysis for the endangered Glenelg spiny crayfish, Euastacus bispinosus. Molecular Biology Reports 40, 4415-4419.

Whiterod, N., Hammer, M. (2012). Population monitoring of Glenelg Spiny Crayfish (Euastacus bispinosus) in rising-spring habitats of lower south east, South Australia. Report to the Friends of Parks Inc. Aquasave Consultants, Adelaide. 27 p.

Special thanks to Friends of Mt Gambier Area Parks, the Norman Wettenhall Foundation and DEWNR for support of recent projects.

 

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