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Riek's Crayfish (Euastacus rieki)

Riek's Crayfish is a small spiny freshwater crayfish endemic to the high country of the ACT and southern NSW. It depends on small to moderate streams, stream margins and bog wetlands, including areas that may be affected by works.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Australian Capital Territory, Nature Conservation Act 2014: Endangered.

Seasonal planning

Berried females have been recorded from April to November in high-altitude habitats in Namadgi and Kosciuszko National Parks.

Seasonal evidence: From published sources for this species.

Timing varies between sites and years.

  • Breeding season: Berried females have been recorded from April to November in high-altitude habitats in Namadgi and Kosciuszko National Parks.

Identification: Appearance

A small spiny crayfish.

A small spiny crayfish.

Identification: Confirming identity

Confirm the identity of any suspected record with a specialist and a photograph or voucher, as required by the relevant permit.

Distribution: Known range

It occurs in the high country of the ACT and southern NSW, usually above 1,000 m and with records from 560 m to 1,600 m. The species was formerly thought to occur in north-eastern Victoria, but specimens from that region have been identified as a different lineage.

It occurs in the high country of the ACT and southern NSW, usually above 1,000 m and with records from 560 m to 1,600 m. The species was formerly thought to occur in north-eastern Victoria, but specimens from that region have been identified as a different lineage.

Distribution: National mapping

The Commonwealth species distribution model (SNES) maps where the species or its habitat is known, likely or may occur. Use it with local records and site inspection.

Habitat: Habitat

Riek's Crayfish inhabits small to moderate streams and their margins, as well as bogs and fens with rushes, sedges and sphagnum. These habitats may be fringed by snow gums, tussock grasses and heath, and are often covered by snow or ice in winter.

Riek's Crayfish inhabits small to moderate streams and their margins, as well as bogs and fens with rushes, sedges and sphagnum. These habitats may be fringed by snow gums, tussock grasses and heath, and are often covered by snow or ice in winter.

Foraging habitat: Diet

The species is likely to be omnivorous.

The species is likely to be omnivorous.

Breeding habitat: Breeding

Two berried females were found in a subalpine bog at about 1,600 m, each carrying around 100 orange eggs. These observations suggest females may retain their eggs over winter.

Two berried females were found in a subalpine bog at about 1,600 m, each carrying around 100 orange eggs. These observations suggest females may retain their eggs over winter.

Sheltering habitat: Shelter

It digs deep, sometimes complex burrows near creeks that can reach the water table, and may extend them horizontally beneath fringing heath and tussock grass. Temporary burrows may also occur under rocks.

It digs deep, sometimes complex burrows near creeks that can reach the water table, and may extend them horizontally beneath fringing heath and tussock grass. Temporary burrows may also occur under rocks.

Threats: Threats

The species is anticipated to be intolerant of high temperatures. Alien predators, particularly foxes, as well as feral dogs and pigs, are identified as threats.

The species is anticipated to be intolerant of high temperatures. Alien predators, particularly foxes, as well as feral dogs and pigs, are identified as threats.

Threats: Works risk

Works that disturb or remove small streams, bogs or stream margins could affect habitat the species depends on. Changes that warm these cool habitats may also be harmful.

Survey methodology: 1. Commonwealth guidance

Use methods consistent with the Commonwealth survey guidelines and engage a specialist with the right permits.

For EPBC Act referrals, survey effort and methods should be consistent with the on-ground surveys and data for referred actions under the EPBC Act, read with the Significant impact guidelines 1.1.

Survey methodology: 2. Limits

A non-detection is not proof of absence. Match survey timing to the species and season, and record effort.

Vegetation associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific vegetation association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Ecosystem associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Soil and substrate associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific soil association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Water and wetland associations: Water-associated habitat mentioned in profile

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

Riek's Crayfish inhabits small to moderate streams and their margins, as well as bogs and fens with rushes, sedges and sphagnum.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: ACT, NSW.

Habitat use: general

Fauna records and mapped habitat: Not yet analysed

Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.

No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.

A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.

Habitat limitations and contrary evidence: No supported exclusion recorded

Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.

This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.

Habitat limitations and contrary evidence: Before using a negative association

  • Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
  • Check survey methods, season, repeated effort and detectability before interpreting non-detection.
  • Investigate credible contradictory records and microhabitats absent from broad mapping.
  • Do not convert a missing map class, low record count or failed data request into species absence.

Before disturbance: 1. Desktop and approvals

Confirm whether the project could affect the species before works begin.

Check national mapping, state records and recent surveys for the site. An action likely to have a significant impact on this nationally listed species needs EPBC Act referral, and state permits apply where it is state listed.

Before disturbance: 2. Plan to avoid

Design the footprint, timing and access to avoid known or likely habitat, and brief crews on what to look for and who to call.

During disturbance: 1. Controls

Keep works inside the approved footprint and conditions.

Fence or mark habitat to be retained and keep machinery, stockpiles and spoil out of it.

During disturbance: 2. Stop and report

If the species is found unexpectedly, stop work at that spot and contact the project ecologist and the relevant agency.

After disturbance: 1. Records

Record outcomes.

Record sightings, habitat lost or retained and any injury or death, and report them under the approval conditions.

Rehabilitation: 1. Restore

Restore disturbed habitat where possible.

Reinstate disturbed ground with local species, return logs, rocks and litter, and control weeds and erosion until the site is stable.

Sources