Fauna Spotters logo

Bidhawal Crayfish (Euastacus bidawalus)

The East Gippsland Spiny Crayfish is a freshwater crayfish endemic to eastern Victoria and south-eastern New South Wales. It uses stream margins, swampy areas and seepage zones, including areas with remnant riparian vegetation, so these habitats are important considerations for works.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Victoria, Flora and Fauna Guarantee Act 1988: Endangered.

Seasonal planning

Breeding starts around May to June; young are carried until December to January for release.

Seasonal evidence: From published sources for this species.

Timing varies between sites and years.

  • Breeding and young release: Breeding starts around May to June; young are carried until December to January for release.

Identification: Appearance

This spiny crayfish has a dark green to brown upper body. Its maximum recorded occipital carapace length is 53 mm.

This spiny crayfish has a dark green to brown upper body. Its maximum recorded occipital carapace length is 53 mm.

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 eastern Victoria and south-eastern New South Wales, in streams and tributaries of the Genoa, Benedore, Wingan, Thurra and Cann rivers. Records are from elevations of 28 to 550 m above sea level in the DCCEEW species information.

It occurs in eastern Victoria and south-eastern New South Wales, in streams and tributaries of the Genoa, Benedore, Wingan, Thurra and Cann rivers. Records are from elevations of 28 to 550 m above sea level in the DCCEEW species information.

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

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas. It can occur in cleared areas where some riparian vegetation remains.

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas. It can occur in cleared areas where some riparian vegetation remains.

Foraging habitat: Diet

It is mainly vegetarian, consuming detrital material, roots and other plant material.

It is mainly vegetarian, consuming detrital material, roots and other plant material.

Breeding habitat: Breeding

Breeding is reported to start around May to June, with young carried until December to January for release. Females are reported to mature at around 40 mm occipital carapace length and to carry 20 to 40 eggs.

Breeding is reported to start around May to June, with young carried until December to January for release. Females are reported to mature at around 40 mm occipital carapace length and to carry 20 to 40 eggs.

Sheltering habitat: Shelter

It spends much of its time in long, deep and complex burrows along stream edges, ephemeral streams and swampy or seepage areas. Burrows may reach the permanent water table and can be mostly water-filled.

It spends much of its time in long, deep and complex burrows along stream edges, ephemeral streams and swampy or seepage areas. Burrows may reach the permanent water table and can be mostly water-filled.

Threats: Threats

Potential pressures include fire and post-fire impacts, climate change, reduced moisture availability and habitat degradation. Loss of riparian vegetation and damage to stream sides and beds are also identified as concerns for the species’ habitat.

Potential pressures include fire and post-fire impacts, climate change, reduced moisture availability and habitat degradation. Loss of riparian vegetation and damage to stream sides and beds are also identified as concerns for the species’ habitat.

Threats: Works risk

Clearing riparian vegetation or degrading stream margins can reduce habitat, and the species is reported from cleared areas only where some riparian vegetation remains. Changes to water quality or flow may also affect it, as it relies on cool, well-oxygenated inland waters and is sensitive to changes in water quality and flow.

Survey methodology: 1. Species-specific methods

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

Night-time searches may detect crayfish moving around creeks and forest floor or pushing mud from burrows during burrow construction. They are rarely attracted to baits or captured in traps, except during floods.

Survey methodology: 2. Commonwealth guidance

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: 3. Limits

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

Vegetation associations: Eucalypt forest

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

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas.

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: NSW, VIC.

Habitat use: general

Vegetation associations: Heath

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas.

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: NSW, VIC.

Habitat use: general

Vegetation associations: Wetland or sedgeland

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas.

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: NSW, VIC.

Habitat use: general

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.

The species is generally found in dry sclerophyll forest and heath-vegetated ridges above streams, as well as stream margins and swampy areas.

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: NSW, VIC.

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