Document ID: chunk:federal_register_of_legislation:F2015L01633:body:0:p17
Version: federal_register_of_legislation:F2015L01633
Segment Type: other
Provision Reference: 
Character Range: 46013–48953

The pygmy blue whales tend to pass along the shelf edge at depths between 500m to 1000m during their migration. Recent tagging studies have provided important new information potentially indicating the general migration pattern and breeding grounds of pygmy blue that feed off the western coast of Australia34. Assuming these movements are representative of the animals that feed off the western Australian area as a whole, pygmy blue whales migrate north from the Perth Canyon / Naturaliste Plateau region in March / April reaching Indonesia by June where they remain until at least September. Southern migration from Indonesia may occur from September and finish by December in the subtropical frontal zone after which the animals may make their way slowly northwards towards the Perth Canyon by March / April.
There are annual acoustic detections of Indo-Australian pygmy blue whales at Scott Reef. Detections of presumably south-bound whales occurs over late October to December70.
Blue whales are also sighted travelling southwards through Geographe Bay in Western Australia from September to December19, but the migratory origin of these whales is largely unknown. It is likely that they pass south of Cape Naturaliste and fan out to feed across southern Australia down to the subtropical convergence (i.e. the confluence of subtropical and subantarctic waters at approximately 40–45⁰ South).
It is thought that pygmy blue whales are likely to migrate along the southern coast of Australia through the western area of the Great Australian Bight and between the two main feeding areas but further research is required to define the migratory paths for pygmy blue whales across this region.

The migratory routes for pygmy blue whales off the east coast of Australia are not known. Strandings of blue whales have occurred on the east coast, though it is not clear whether stranded whales were associated with the Indo-Australian or Tasman-Pacific populations.  An acoustic noise logger in Bass Strait has picked up acoustic detections from pygmy blue whales in May-June, indicative of animals heading east but too late in the season for them to be heading up the Western Australian coast.. Detection of these vocalisations could also be indicative of individuals that have forgone low-latitude migration, seeking alternative wintering grounds in temperate waters. There have also been regular acoustic detections of Tasman-Pacific type blue whale calls along the east coast of Australia, and elevated levels of underwater noise in frequency bands of Tasman-Pacific vocalisations, which suggests that this population of blue whales may utilise the Tasman Sea year round73.
Antarctic Blue Whales
Acoustic recordings of Antarctic blue whales off Western Australia and Tasmania suggest these areas may form part of their migratory route between Antarctica and more northern wintering grounds42, 71,106.
Southern Hemisphere Distribution
Blue