|Scientific Name:||Euastacus australasiensis|
|Species Authority:||(H. Milne-Edwards, 1837)|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Furse, J. & Coughran, J.|
|Reviewer(s):||Collen, B. & Richman, N.|
|Contributor(s):||Livingston, F., Soulsby, A.-M., Batchelor, A., Dyer, E., Whitton, F., Milligan, H.T., Smith, J., Lutz, M.L., De Silva, R., McGuinness, S., Kasthala, G., Jopling, B., Sullivan, K. & Cryer, G.|
Euastacus australasiensis has been assessed as Least Concern. This species has a large extent of occurrence and a large altitudinal range (0-1,100 m above sea level). It also occurs in a variety of habitats from small streams to large rivers. This crayfish occurs within national parks, and although there are no specific management plans for this species, it indirectly benefits from general park protection. Monitoring and further research on the population status and life history characteristics of this species is needed to better understand how this species is impacted by current threats and potential future threats.
|Range Description:||This species is endemic to eastern Australia. It is found at altitudes ranging from sea level to 1,100 m above sea level (Morgan 1997). Its range extends 120 km north-south along the coast from Ourimbah, south through Sydney to Wollongong, and approximately 150 km west into the Blue Mountains, New South Wales (J.M. Furse and J. Coughran pers. comm. 2008). Its range is drained by small coastal streams including tributaries of the Hawkesbury and Port Hacking Rivers, and in higher country by tributaries of the Grose and Coxs Rivers (Morgan 1997). The species extent of occurrence (EOO) is less than 20,000 km2 (J.M. Furse and J. Coughran pers. comm. 2008).|
Native:Australia (New South Wales)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There are no population data available for this species, although it has been recorded from numerous localities within its distribution (J.M. Furse and J. Coughran pers. comm. 2008). Merrick (1995) suggested that large scale urban and industrial developments might be a factor in local declines in abundance of this species|
|Habitat and Ecology:||
This species is found in lotic situations, ranging from small streams to large rivers (Growns and Marsden 1998). The geology of the area is mostly sandstone and granite and the vegetation is primarily eucalypt and heath forest with occasional patches of temperate rainforest, however, some areas have been largely cleared of vegetation (Morgan 1997).
The slow growth rate and low fecundity of many Euastacus species renders them less resilient to reduction in population numbers through habitat destruction and catastrophic events (Van Praagh 2003).
This species is found in national parks in the Blue Mountains region of its distribution and so is unlikely to be affected by habitat destruction within national park boundaries. However, due to increasing human population and urbanisation in the region there is an increased risk of fire, habitat loss and pollution (Merrick 1995; Growns and Marsden 1998). Recreational fin-fish angling poses a two-fold threat, the direct impacts of the introduced trout (i.e. predation of crayfish) and the potential introduction of an exotic species of crayfish as bait (Cherax destructor, i.e. competition) (Merrick 1995, Merrick 1997, Growns and Marsden 1998).
Other exotic species (foxes, goats, cats, pigs) that have generally been found to impact on crayfish (Green and Osbourne 1981, Horwitz 1990, Merrick 1995, Eyre et al. 1997, ACT Government 2007, O’Brien 2007) also occur in this species’ range (DEH 2004a,b,c,d), and could have localized impacts on this species and contribute to declines in distribution and/or abundance.
Although this species occurs over a wide altitudinal range, it is probably susceptible in the long run to climate change, as are other species in the genus Euastacus (Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006, Westoby and Burgman 2006, IPCC 2007).
There are no species-specific conservation measures in place for this species, although some of the subpopulations in the Blue Mountains do exist within national parks (J.M. Furse and J. Coughran pers. comm. 2008).
Research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, investigations into thermal tolerance and resilience to exotic species. In New South Wales, a minimum recreational size limit of 90 mm OCL is in place for any spiny crayfish (NSW DPI 2007). Euastacus australasiensis does not attain that size, and so is indirectly protected by this restriction (J.M. Furse and J. Coughran pers. comm. 2008).
|Citation:||Furse, J. & Coughran, J. 2010. Euastacus australasiensis. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 28 July 2015.|
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