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Blue Whale (Balaenoptera musculus)

The blue whale is a baleen whale and the largest animal known to have existed. It occurs in Australian marine waters, with open ocean and continental shelf edges providing important habitat. [2][11]

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Victoria, Flora and Fauna Guarantee Act 1988: Endangered.

South Australia, National Parks and Wildlife Act 1972: Endangered.

Western Australia, Biodiversity Conservation Act 2016: Endangered.

Tasmania, Threatened Species Protection Act 1995: Endangered.

Commonwealth, EPBC Act 1999: Listed migratory. Listed migratory species are a matter of national environmental significance, so a significant impact needs referral.

Seasonal planning

Pygmy blue whales are sighted off southwestern Victoria from November to May, arriving at the Bonney Upwelling by mid-November and departing by the end of April.

Seasonal evidence: From published sources for this species.

Timing varies between sites and years.

  • Present off southern Australia: Pygmy blue whales are sighted off southwestern Victoria from November to May, arriving at the Bonney Upwelling by mid-November and departing by the end of April.

Identification: Appearance

This very large whale has a bluish-grey, often mottled body, a broad flat head and a small dorsal fin set well back on the body. Long throat grooves extend along the underside. [5][8]

This very large whale has a bluish-grey, often mottled body, a broad flat head and a small dorsal fin set well back on the body. Long throat grooves extend along the underside. [5][8]

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

Blue whales occur in oceans worldwide except the Arctic, and populations commonly migrate between higher-latitude feeding grounds and lower-latitude waters. Some populations may remain in the same area year-round. [2][3]

Blue whales occur in oceans worldwide except the Arctic, and populations commonly migrate between higher-latitude feeding grounds and lower-latitude waters. Some populations may remain in the same area year-round. [2][3]

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

They mainly inhabit open ocean and continental shelf edges, often in cold, productive waters where krill are concentrated. They may also occur near coasts and islands. [5][11]

They mainly inhabit open ocean and continental shelf edges, often in cold, productive waters where krill are concentrated. They may also occur near coasts and islands. [5][11]

Foraging habitat: Diet

Blue whales feed mainly on krill, filtering prey from seawater with baleen plates. They often feed in dense patches of krill. [8][10]

Blue whales feed mainly on krill, filtering prey from seawater with baleen plates. They often feed in dense patches of krill. [8][10]

Breeding habitat: Breeding

Breeding and calving generally occur in warmer, lower-latitude waters. Gestation is about 11 to 12 months, and females typically have a calf every two to three years. [5][8]

Breeding and calving generally occur in warmer, lower-latitude waters. Gestation is about 11 to 12 months, and females typically have a calf every two to three years. [5][8]

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

In areas of high human activity, ship noise, entanglement and vessel collisions may affect blue whales; these events are reported as rare. [13]

In areas of high human activity, ship noise, entanglement and vessel collisions may affect blue whales; these events are reported as rare. [13]

Threats: Works risk

Vessel activity associated with development may expose blue whales to ship noise, entanglement and collisions, particularly in areas of high human activity. [13]

Survey methodology: 1. Species-specific methods

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

Detection and study methods described for blue whales include sightings, acoustic detections and photo-identification. [3][6]

Survey methodology: 2. Commonwealth guidance

For EPBC Act referrals, survey effort and methods should be consistent with the ePBC Act publications, including the National Guidelines for the Survey of Cetaceans, Marine Turtles and the Dugong (2024), 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