|Scientific Name:||Euastacus suttoni Clark, 1941|
|Red List Category & Criteria:||Vulnerable 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 suttoni has been assessed as Vulnerable under criterion B1ab(iii). This species has an estimated extent of occurrence of 10,000 km2, and a severely fragmented distribution as a result of intervening areas of unsuitable habitat. There are a number of threats to this species, and its habitat including cattle grazing, loss of riparian strips, land clearance, and poaching. It is also faces further potential threats from exotic species and climate change though the degree to which this are known to impact the population is unknown. Monitoring of the population trends of this species is needed along with a review of the habitat status to assess the degree to which the entire population is being affected by threats.
|Range Description:||This species is endemic to Australia. Its range extends from the Stanthorpe area, southern Queensland, 120 km south to Dundee near Glen Innes, New South Wales, and east along the Gibraltar Range into Washpool and Gibraltar Range national parks (Coughran 2008 unpublished data, J.Coughran and J.M. Furse pers. comm. 2009). It has also recently been recorded in Ewingar State Forest, north of Washpool State Forest (Leckie and Coughran 2005). The range is drained by tributaries of the Severn, Dumaresque and Clarence rivers (Morgan 1997). This species is typically collected at altitudes greater than 680 m above sea level (usually above 1,000 m) (Morgan 1988). As a highland species, it inhabits upper reaches of different drainages, and the species can thus be considered severely fragmented across its range due to the barrier effects of mountain ridges and unsuitable habitat in the intervening lowlands (Morgan 1997, Ponniah and Hughes 2006). This species has an estimated extent of occurrence of 10,000 km² ( J.Coughran and J.M. Furse pers. comm. 2009).|
Native:Australia (New South Wales, Queensland)
|Range Map:||Click here to open the map viewer and explore range.|
There is no population information available for this species. Though, it is thought that it may be locally abundant in some of the highland sites it occurs in (J. Coughran and J.M Furse pers. comm. 2009).
|Current Population Trend:||Unknown|
|Habitat and Ecology:|| |
This species inhabits headwater streams (Morgan 1997). Most of the areas are in dry eucalypt forests, alpine heath swamps, and rainforest with this species favouring granitic soils mixed with extruding bedrock, and cobble and boulders (J. Coughran and J.M Furse pers. comm. 2009). Specimens inhabit large water bodies and have also been found in shallow water beneath rocks (J. Coughran and J.M Furse pers. comm. 2009). In general, they do not appear to make burrows in sandy streams, but do however in marshy areas away from the main stream channel (Leckie and Coughran 2005). Permanent water is not an essential habitat requirement for this species, and neither is access to the water table (J. Coughran and J.M Furse pers. comm. 2009). This species has been found burrowed under ground near ground water. Although not dependent on permanent water, the species is restricted to highland sites of appreciable altitudes, indicating a requirement for cool conditions (J. Coughran and J.M Furse pers. comm. 2009).
|Use and Trade:||This species is taken from the wild by collectors.|
This species is fairly tolerant to minor clearing, and has been recorded in lightly disturbed areas such as those adjacent to roadworks, low density cattle farming and largely intact riparian zones (J. Coughran and J.M. Furse pers. comm. 2009). It has not, however, been recorded from sites that have been appreciably cleared for agriculture (J. Coughran and J.M. Furse pers. comm. 2009). For example, this species is absent from areas where cattle are farmed at high density, in particular where cattle have access to the creeks, and riparian vegetation has either been largely cleared, or replaced through weed infestation (Leckie and Coughran 2005).
This species occurs within some national parks but is susceptible to potential threats such as climate change, exploitation and the introduction of exotic species (Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006,Westoby and Burgman 2006, IPCC 2007). Furthermore, it is restricted to very high altitudes, and it is probable that this reflects a requirement for cool conditions (J. Coughran and J.M Furse pers. comm. 2009).
There has been some evidence of poaching in some protected areas that coincide with the species range (i.e. Bald Rock National Park). As this is a slow growing species, there is the potential for localised depletion as a result of a single fishing trip (Leckie and Coughran 2005). As yet this is not considered a major threat but if recreational fishing of the species intensifies it may be. Recreational fishing (in particular the taking of large adults) has the capacity to lead to serious and far reaching impacts on population structure (i.e. the stunted population phenomenon (Huner and Lindqvist 1985, Tulonen et al. 2008)), including impairment of reproductive success in females (Tulonen et al. 2008). The streams in several areas are also heavily modified by anthropogenic activities such as fossicking for mineral and gemstones, which may adversely impact on water quality.
This species is also susceptible to the threat of introduced exotic species; there is a potentially large scale threat from Cane Toads (Bugo marinus) (DEH 2004b) although there is no specific data on impacts for this species (J. Coughran and J.M. Furse pers. comm. 2009). Large areas of stream habitat have been totally rooted by feral pigs (Coughran 2008 unpublished data, J. Coughran and J.M. Furse pers. comm. 2009). In addition, other 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 could have localized impacts on the species distribution and abundance (J. Coughran and J. M. Furse pers. comm. 2009).
There are no species-specific conservation measures in place for this species. However, its distribution range coincides with several national parks (J. Coughran and J.M. Furse pers. comm. 2009). In New South Wales, a minimum recreational size limit of 90 mm orbital carapace length (OCL) is in place for all 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). All Euastacus species in Queensland are officially no take species under the Fisheries Act 1994 and must be released if captured (DPIF 2007). There is no information available on the levels of compliance, although evidence of illegal poaching has been observed for this species (J. Coughran and J.M. Furse pers. comm. 2009).
Further research should include population assessment and monitoring, biological and life history information, investigations into thermal tolerance and resilience to exotic species. A detailed study into the population genetics of this species is urgently required (J. Coughran and J.M. Furse pers. comm. 2009).
|Citation:||Coughran, J. & Furse, J. 2010. Euastacus suttoni. The IUCN Red List of Threatened Species 2010: e.T153727A4537203.Downloaded on 26 May 2018.|
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