|Scientific Name:||Euastacus polysetosus|
|Species Authority:||Riek, 1951|
|Red List Category & Criteria:||Endangered B1ab(iii) ver 3.1|
|Assessor(s):||Coughran, J. & Furse, J.|
|Reviewer(s):||Collen, B. & Richman, N.|
|Contributor(s):||Livingston, F., 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 polysetosus has been assessed as Endangered under criterion B1ab(iii). This species has a severely fragmented distribution, and an extent of occurrence of approximately 750 km2. There has been a continuing decline in the quality of habitat due to the destructive nature of a number of exotic species in the area, some of which also predate upon this species. There is also destruction of suitable rainforest habitat in parts of its range. This species also faces the consequences of global temperature rise. As a restricted range species, dependent on cool, clear headwater streams, a slight increase in temperature could rapidly extirpate this species. Research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, and resilience to effects of exotic species.
This species is endemic to Australia, it is found in the Barrington Tops area (60 km West of Taree) in New South Wales (Morgan 1997); the range falls across two different coastal drainages: the Manning and Hunter rivers (Morgan 1997). It is found at altitudes greater than 1,000 m above sea level, and due to its restriction to upland sections of the streams it inhabits, it can be considered as severely fragmented across its range, due to the barrier effects of mountain ridges and unsuitable lowland habitat (Morgan 1997, Ponniah and Hughes 2006). This species has an extent of occurrence of approximately 750 km2 (J. Courghran and J.M. Furse pers. comm. 2009).
Native:Australia (New South Wales)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is no population information available for this species.|
|Habitat and Ecology:||
This species inhabits streams at altitudes over 1,000 m above sea level. Stream banks are vegetated by dry sclerophyll forest and tree ferns, sub-alpine grassland with snow gums and negrohead beech forest (Morgan 1997).
Given its highly restricted range, this species is extremely susceptible to localized threats, including bush fires, forest management practices, habitat destruction and over exploitation by collectors (J. Coughran and J.M. Furse pers. comm. 2009). This species is also susceptible to climate change, including increasing temperature, alterations to hydrological regimes, severe weather events and loss of suitable highland habitat (Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006, Westoby and Burgman 2006, IPCC 2007).
There is a potential large scale threat from Cane Toads (Rhinella marina) (DEH 2004b) although there is no specific information on impacts upon this species. Other introduced exotic species (cats, foxes, pigs, goats) 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,c,d,e) and given this species highly restricted distribution, could have serious impacts by contributing to declines in its distribution and/or abundance (J. Coughran and J.M. Furse pers. comm. 2009). Due to the narrow thermal tolerance of this species, and its restricted range (restricted to cool, headwater streams in forested catchments), global temperature increase has resulted in range contraction. This species is further compromised by the presence of exotic species (goats, feral pigs, foxes, Cane Toads and cats) which are known to predate on crayfish and degrade riparian habitat; while the precise effects of these threats on this species are not yet well understood, they are believed to be significantly impacting the long term viability of the population (J. Furse and J. Coughran pers. comm. 2010).
There are no species specific conservation measures in place for this species, however its distribution range coincides with the Barrington Tops World Heritage site. Furthermore, in New South Wales, a minimum recreational size limit of 90 mm orbital carapace length (OCL) is in place for any spiny crayfish (NSW DPI 2007); this species does not attain that size, and so is indirectly protected by this restriction (J. Coughran and J.M. Furse pers. comm. 2009).
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 (J. Coughran and J.M. Furse pers. comm. 2009).
|Citation:||Coughran, J. & Furse, J. 2010. Euastacus polysetosus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 06 July 2015.|
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