Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Endangered
Listing and Conservation Advices Commonwealth Listing Advice on Engaeus spinicaudatus (Scottsdale Burrowing Crayfish) (Threatened Species Scientific Committee, 2001ad) [Listing Advice].
 
Recovery Plan Decision Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
 
Adopted/Made Recovery Plans Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
 
Policy Statements and Guidelines Draft referral guidelines for four threatened Tasmanian burrowing crayfish (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011s) [Admin Guideline].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (14/07/2001) (Commonwealth of Australia, 2001g) [Legislative Instrument].
 
State Government
    Documents and Websites
TAS:Tasmania's Freshwater Burrowing Crayfish (Department of Primary Industries and Water (DPIW), 2007) [Information Sheet].
TAS:Engaeus spinicaudatus (Scottsdale Burrowing Crayfish): Species Management Profile for Tasmania's Threatened Species Link (Threatened Species Section (TSS), 2014si) [State Action Plan].
State Listing Status
TAS: Listed as Endangered (Threatened Species Protection Act 1995 (Tasmania): September 2012)
Non-statutory Listing Status
IUCN: Listed as Critically Endangered (IUCN Red List of Threatened Species: 2011.2)
Scientific name Engaeus spinicaudatus [66780]
Family Parastacidae:Decapoda:Malacostraca:Arthropoda:Animalia
Species author Horwitz, 1990
Infraspecies author  
Reference ANZECC Threatened Fauna List May 2000
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images
http://www.crayfishworld.com/image/Engaeus-spin.jpg

The Scottsdale Burrowing Crayfish is a small, freshwater crayfish. It grows to approximately 5 cm in length (Bryant & Jackson 1999b) and has small, but prominent, spines on the outer flaps of the tail which extend past the edge of the tail flap (LEC 2003).

The Scottsdale Burrowing Crayfish has a small distribution north-east of Scottsdale, Tasmania. The species has considerable overlap with other crayfish from the Engaeus species including E. tayatea, E. mairener, E. leptorhynchus, E. orramakunna and E. cunicularius (Doran & Richards 1996). The Scottsdale Burrowing Crayfish has been well documented and is known at the following sites (Horwitz 1991):

  • tributary of Forester River
  • east of Old Waterhouse Road (three distinct locations)
  • above the Forester River
  • Surveyors Creek area (four distinct locations)
  • tributary of Surveyors Creek
  • north of Surveyors Creek and Forester River Junction
  • Forester River Plains
  • south (400 m) of Forester Road
  • China Creek
  • Forester Flats (two distinct locations)
  • next to Hang Dog Creek.

The Scottsdale Burrowing Crayfish has been well surveyed and is locally abundant within its range. Population estimates from 1999 range from 1 360 000 to 2 670 000 adult individuals (Doran 1999b).

The Scottsdale Burrowing Crayfish is found primarily in wet buttongrass (Gymnoschoenus sphaerocephalus) and heathy plains (particularly with peaty and permanently saturated soils) (Doran & Richards 1996). They are also known to occur in surface seepages, the floodplains of creeks (often with scrubby or taller tea-tree vegetation), wet areas converted to pasture, and some creekbanks in open dry eucalypt forests (Doran & Richards 1996; Horwitz 1991; Wapstra et al. 2006).

Riparian habitats are used by the Scottsdale Burrowing Crayfish, making associated instream hydrological cycles important. The vegetation surrounding riparian habitat helps to stabilise substrates in bank and floodplain habitats and helps maintain groundwater levels. Seasonal instream flows also maintain groundwater levels and the moisture content of soils. High flow events may provide important cues for stages in the life cycle of the species. Access to groundwater is particularly important for the Scottsdale Burrowing Crayfish, and water levels less than one metre below the ground are suitable for the species (DPIW 2007b).

The burrows of Scottsdale Burrowing Crayfish are connected to the water table, and derive water from groundwater and surface run-off (Horwitz & Richardson 1986). Burrows have been known to extend 10 m from the creekbank, occurring in areas that are most likely permanently saturated (Wapstra et al. 2006).

The species extent of occurrence is estimated at 34.5 km², however the potential habitat available has been calculated as only 3.881km². Of the potential habitat, 22.5% is found on private land, 12.8% on Crown land and 64.7% in State forests (Doran 1999b).

Female Scottsdale Burrowing Crayfish become reproductively mature at an occipital carapace length (length between eyes and end of main body segment) of 16.4 mm. Mating occurs between mid November and late December, which is believed to be the only time that male crayfish are found wandering the soil surface. The females carry the eggs and larvae through December and January, and have been observed with free-living young in their burrows in early March. A strong linear relationship exists between body size and fecundity, however no information exists for rate of growth, mortality rates, age or breeding frequency (Doran 1999b).

Distinctiveness
The Engaeus genus, which includes the Scottsdale Burrowing Crayfish, can be distinguished from other freshwater crayfish on the basis of size (Engaeus species are very small); claw orientation and shape; carapace (shield covering the back) grooves; and the location and number of spines on the body (DPIW 2007; Horwitz 1988).

Survey methods
The following survey methods were developed during a workshop in June 2010 and are recommended for presence/absence surveys (Tasmanian Burrowing Crayfish Workshop 2010). Where it is not possible to conduct surveys in this manner, failure to detect burrowing crayfish should not be considered indicative of their absence.

Surveys should:

  • maximise the chance of detecting the species
  • determine the context of the site within the broader landscape
  • account for uncertainty and error (such as false presences and absences)
  • be conducted by a suitably qualified person with experience in burrowing crayfish surveys, or in consultation with burrowing crayfish experts.

Visual search
The first step in surveying for burrowing crayfish is a visual search to locate burrows within suitable habitat. Presence of burrows in suitable habitat indicates the presence of burrowing crayfish. The recommended minimum search effort is one hour per hectare (Tasmanian Burrowing Crayfish Workshop 2010).

Species identification
In areas where only one burrowing crayfish species occurs, the presence of crayfish burrows confirms the presence of that species. However, in some areas, more than one crayfish species may be present (that is, the species occur together). In an area of overlapping distributions, further investigation is needed once burrows have been located to determine the species occupying a particular microhabitat. This will usually involve burrow excavation. Burrow excavation surveys must be designed and implemented in a way that minimises the disturbance to habitat at the site and should only be conducted in consultation with burrowing crayfish experts. Survey methodology should include appropriate hygiene controls to avoid the spread of pathogens such as chytrid fungus and Phytophthora in burrowing crayfish habitat. Permits may be needed for burrow excavation surveys (Tasmanian Burrowing Crayfish Workshop 2010).

The main threats to the Scottsdale Burrowing Crayfish are forestry and agricultural activities, inappropriate fire management, and downstream effects of road construction (Doran 1999b). Scottsdale Burrowing Crayfish are most vulnerable to fire, ploughing, stock and herbicides or pesticides during their mating season of November to December (Doran &Richards 1996).

Hydrological changes
Drainage of swampland is a major threat to the species as it lowers the water table, alters water parameters, and potentially impedes the ability of the animals to utilise peat layers (Doran & Richards 1996). Scottsdale Burrowing Crayfish are dependant on instream hydrological cycles, especially high flows and flood events, to maintain their riparian habitats. Native riparian vegetation helps to stabilise stream banks and floodplain habitats, and helps to maintain groundwater levels (DPIW 2007b).

Soil disturbance
Habitat converted to pasture threatens the species through the introduction of exotic plants, ploughing, fertilising, grazing by hooved animals, potentially higher water temperatures, and eutrophication. Trampling by cattle is a direct threat to crayfish at times of the year when they are close to or on the surface (predominantly during the mating period of November and December) (Doran & Richards 1996).

Potential threats
Inappropriate fire management poses a potential threat to the Scottsdale Burrowing Crayfish, and an uncontrolled fire of high intensity or inappropriate burning practices could be devastating to a species of such limited distribution (Doran & Richards 1996). High intensity fires are a direct threat to the peaty soils in which the species' burrows are found, while the absence of fire may promote successional change and eventual drying of the associated buttongrass communities (Doran 1999b). Peat habitats are most vulnerable to fire in December to March or April, depending on rainfall (Doran & Richards 1996).

Other threats
The lack of sizable reserved habitat also poses a threat to the species. Over two thirds of the species' habitat is found in State Forests, and, as such, is subject to forestry activities. While much of the habitat contains few loggable trees, forestry activities in higher catchments may advance soil erosion. The large numbers and small range of Scottsdale Burrowing Crayfish makes the species vulnerable to stochastic processes (Doran 1999b).

The Burrowing Crayfish Group Recovery Plan 2001–2005 (Doran 1999b) was developed to stabilise and improve the conservation status of the species. Specific objectives included increased habitat protection for the species, an increase in public awareness and involvement in the species' protection and to ensure the species' long-term survival. The following recovery actions were recommended (Doran 1999b):

  • habitat assessment
  • improvement of reservation status for the species
  • habitat management within agricultural areas; forestry and commercial harvesting areas; and urban areas
  • community involvement and education
  • population and habitat monitoring.

Landholder advice

If you have burrowing crayfish in your area, activities that would assist the species include (DPIW 2006):

  • ensuring that adequate advice is sought from State and Commonwealth environment agencies prior to development activity
  • fencing of streamsides and seepages to reduce livestock and erosion impacts
  • revegetation of degraded streamside vegetation
  • limiting pollutants from entering waterways.

Management documents for the Scottsdale Burrowing Crayfish include:

  • Burrowing Crayfish (Engaeus) Group Recovery Plan 2001–2005(Doran 1999b).
  • Management Requirements for Rare and Threatened Burrowing Crayfish in Tasmania (Doran & Richards 1996).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Agriculture and Aquaculture:Agriculture and Aquaculture:Fertiliser application Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Agriculture and Aquaculture:Agriculture and Aquaculture:Land clearing, habitat fragmentation and/or habitat degradation Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Agriculture and Aquaculture:Livestock Farming and Grazing:Habitat loss and modification due to clearance of native vegetation and pasture improvements Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Biological Resource Use:Logging and Wood Harvesting:Habitat disturbance due to foresty activities Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Energy Production and Mining:Mining and Quarrying:Habitat destruction, disturbance and/or modification due to mining activities Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Energy Production and Mining:Mining and Quarrying:Habitat modification through open cut mining/quarrying activities Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, grazing, predation and/or habitat degradation by rats Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Natural System Modifications:Dams and Water Management/Use:Changes in hydrology including habitat drainage Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Natural System Modifications:Dams and Water Management/Use:Changes to hydrology including construction of dams/barriers Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Species Stresses:Indirect Species Effects:Low numbers of individuals Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Transportation and Service Corridors:Roads and Railroads:Development and/or maintenance of roads Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].
Transportation and Service Corridors:Transportation and Service Corridors:Road and rail maintenance works Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005 (Doran, N., 1999b) [Recovery Plan].

Bryant, S. & J. Jackson (1999b). Tasmania's Threatened Fauna Handbook: What, Where and How to Protect Tasmania's Threatened Animals. Hobart, Tasmania: Threatened Species Unit, Parks and Wildlife Service.

Department of Primary Industries and Water (DPIW) (2007). Tasmania's Freshwater Burrowing Crayfish. [Online]. Hobart, Tasmania: DPIW. Available from: http://www.dpiw.tas.gov.au/inter.nsf/WebPages/LJEM-73J92W?open.

Department of Primary Industries and Water (DPIW) (2007b). Habitat preferences and water requirements of the Mt. Arthur burrowing crayfish (Engaeus orramakunna) and the Scottsdale burrowing crayfish (Engaeus spinicaudatus). Tasmania: Water Resources Division, DPIW.

Doran, N. (1999b). Burrowing Crayfish (Engaeus) Group Recovery Plan 2001-2005. [Online]. Tasmania: Parks and Wildlife Service, Department of Primary Industries, Water and Environment. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/burrowing-crayfish/index.html.

Doran, N. & K. Richards (1996). Management requirements for rare and threatened burrowing crayfish in Tasmania. In: Report to the Tasmanian RFA Environment and Heritage Technical Committee. [Online]. Hobart: Tasmanian Public Land Use Commission, Forestry Tasmania. Available from: http://www.daff.gov.au/rfa/regions/tasmania/environment/crayfish.

Horwitz, P. (1991). The conservation biology of Engaeus spinicaudatus, a threatened crayfish from north-eastern Tasmania. Report to the Australian National Parks and Wildlife Service, Canberra.

Horwitz, P. & A. Richardson (1986). An Ecological Classification of the Burrows of Australian Freshwater Crayfish. Australian Journal of Marine Freshwater Research. 37:237-242.

International Union for Conservation of Nature (IUCN) (2010). IUCN Red List of Threatened Species. Version 2010.4. [Online]. Available from: http://www.iucnredlist.org.

Launceston Environment Centre (LEC) (2003). Tasmania's Freshwater Burrowing Crayfish (Engaeus sp.) and the Mainland Yabby. [Online]. Launceston, Tasmania: LEC. Available from: http://www.lec.org.au/engaeus/resources/4/yabby%20notesheet.pdf.

Tasmanian Crayfish Workshop (2010). Proceedings of the Tasmanian Crayfish Workshop, 28-29 June 2010. Devonport, Tasmania.

Wapstra, M., K. Richards, S.A. Munks & N.E. Doran (2006). Previously Undescribed Habitat of the Scottsdale Burrowing Crayfish Engaeus Spinicaudatus (Decapoda: Parastacidae). The Tasmanian Naturalist. 128:26-36.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Engaeus spinicaudatus in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 18 Apr 2014 02:37:49 +1000.