Fauna Spotters logo

Maugean Skate (Zearaja maugeana)

The Maugean Skate is a ray known from Macquarie and Bathurst Harbours in western Tasmania, with Macquarie Harbour considered to hold the remaining viable population. It mainly occupies shallow, brackish estuarine channels over the seabed, habitat that may be affected by changes to water quality and flows.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Tasmania, Threatened Species Protection Act 1995: Endangered.

Seasonal planning

Maugean Skates can reproduce throughout the year in Macquarie Harbour, although reproductive activity probably declines in summer.

Seasonal evidence: From published sources for this species.

Timing varies between sites and years.

  • Breeding season: Maugean Skates can reproduce throughout the year in Macquarie Harbour, although reproductive activity probably declines in summer.

Identification: Appearance

This is a dark brown, medium-sized skate with a flat body and large, wing-like pectoral fins. Mature females can reach about 84 cm in total length.

This is a dark brown, medium-sized skate with a flat body and large, wing-like pectoral fins. Mature females can reach about 84 cm in total length.

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

The species is known from two isolated estuaries in southwestern Tasmania: Macquarie Harbour and Bathurst Harbour. Macquarie Harbour is considered to hold the sole remaining viable population; the status of the Bathurst Harbour population is uncertain.

The species is known from two isolated estuaries in southwestern Tasmania: Macquarie Harbour and Bathurst Harbour. Macquarie Harbour is considered to hold the sole remaining viable population; the status of the Bathurst Harbour population is uncertain.

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 Maugean Skate is demersal and mainly inhabits shallow, brackish estuarine channels, particularly at depths of 5 to 15 m. It can occur across a wider depth range, and egg cases have been recorded at 2 to 52 m.

The Maugean Skate is demersal and mainly inhabits shallow, brackish estuarine channels, particularly at depths of 5 to 15 m. It can occur across a wider depth range, and egg cases have been recorded at 2 to 52 m.

Foraging habitat: Diet

Its diet includes crabs, carid shrimp and mysids.

Its diet includes crabs, carid shrimp and mysids.

Breeding habitat: Breeding

Egg cases have been recorded at depths of 2 to 52 m. Females mature at about 4 to 6 years of age.

Egg cases have been recorded at depths of 2 to 52 m. Females mature at about 4 to 6 years of age.

Sheltering habitat: Shelter

Not documented in the published sources used for this profile.

Not documented in the published sources used for this profile.

Threats: Threats

Low oxygen levels associated with intensive salmon farming and altered river flows for hydroelectricity production are identified as threats. Other reported pressures include climate change and extreme weather, accidental capture in local fisheries, and historic mining pollution.

Low oxygen levels associated with intensive salmon farming and altered river flows for hydroelectricity production are identified as threats. Other reported pressures include climate change and extreme weather, accidental capture in local fisheries, and historic mining pollution.

Threats: Works risk

Activities that deplete oxygen in Macquarie Harbour or alter river flows into it could affect the skate and its estuarine habitat. Accidental capture in local fisheries is also reported as a threat.

Survey methodology: 1. Species-specific methods

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

Environmental DNA (eDNA) sampling has been used to investigate the species’ distribution, identifying that most, if not all, of the remaining population is in Macquarie Harbour.

Survey methodology: 2. Commonwealth guidance

For EPBC Act referrals, survey effort and methods should be consistent with the survey guidelines for Australia's threatened fish, 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

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

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

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

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

Plan in-water works, vessel movements and lighting to avoid known habitat and sensitive periods, and set observer and shutdown procedures before works start.

During disturbance: 1. Controls

Keep works inside the approved footprint and conditions.

Use spotters and exclusion zones for in-water works and vessels, and pause works if the species is seen within the zone.

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.

Remove temporary structures, restore natural flow and substrate, and monitor water quality until it returns to baseline.

Sources