Document ID: chunk:federal_register_of_legislation:F2015L01633:body:0:p4
Version: federal_register_of_legislation:F2015L01633
Segment Type: other
Provision Reference: 
Character Range: 8945–11917

and the Bonney Upwelling, and to waters as far east as off Tasmania.
They have known feeding grounds in the Perth Canyon off Western Australia, and the Bonney Upwelling System and adjacent waters off Victoria, South Australia and Tasmania. These areas are utilised from November to May. They migrate between these feeding aggregation areas, northwards and southwards along the west coast of Australia, to breeding grounds that are likely to include Indonesia.
Indo-Australian 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 (the confluence of subtropical and subantarctic waters (40-45° S)) after which the animals may make their way slowly northwards again.
The pre- and post-whaling abundance and population trend of the pygmy blue whale population is unverified, but preliminary estimates of contemporary numbers from Australia are very low relative to estimates of the number of pygmy blue whale catches.

Antarctic blue whales

The Antarctic blue whale subspecies consists of one or more populations that feed off Antarctica, including off the Australian Antarctic Territory, and limited evidence suggests that some proportion migrate at least to subtropical latitudes of the Pacific and Indian Ocean to breed. However, some proportion of Antarctic blue whales may not migrate every year and/or migration may be staggered throughout the year with some whales visiting waters surrounding the Antarctic Continent outside of the summer feeding season.
Off Western Australia, the Antarctic subspecies has been acoustically detected off Cape Leeuwin from May to November, and the Perth Canyon from May to October (with a few occurrences recorded in March), and off the west and north coasts of Tasmania predominately from May to December. Based on the seasonality of recordings, these areas possibly form part of their migratory route, breeding habitat or a combination of the two.
Estimates of pre- and post-whaling abundance of Antarctic blue whales indicate that they have been increasing in abundance since the cessation of whaling. The estimated original population size was 239,000 (95% interval 202,000 – 311,000).  A more recent estimate of the Antarctic Blue Whale population was 2,280 (95% interval 1,160 – 4,500) individuals in 1996 (estimated from the circumpolar International Decade of Cetacean Research, Southern Ocean Whale and Ecosystem Research survey conducted from the 1992/1993 to 2003/2004 season).

Threats
There are several anthropogenic threats that may inhibit the recovery of blue whale populations in Australian waters. The relevance of these threats to the two subspecies varies depending on the habitats they occupy, timing of habitat occupancy and their population abundance and trend. The highest rated