Document ID: chunk:federal_register_of_legislation:F2015L01633:body:0:p18
Version: federal_register_of_legislation:F2015L01633
Segment Type: other
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Character Range: 48664–51781

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 whale catches in the 20th century during the feeding season were recorded almost continuously from around Tasmania, then westward to the south of the Bonney Upwelling and Great Australian Bight past Cape Leeuwin, then across the southern Indian Ocean to south of Madagascar and the Crozet Islands in the sub-Antarctic19. This continuous strip of catches includes high primary productive areas, such as the Southern Tropical Convergence82 and the Crozet Islands90,100,111 where Indo-Australian pygmy blue whale and Antarctic blue whale acoustic calls have been recorded97, and the Madagascar Plateau65 where blue whales of unknown population identity have recently been recorded13.
Contemporary acoustic recordings from 2004 and 2006 have detected the unique call of Australian blue whales during February, March and April off the Crozet Islands97 and south of Australia in the sub-Antarctic (54⁰ South, 142⁰ East)42respectively. Similar recordings in 2007 off the Crozet Islands did not detect any Indo-Australian pygmy blue whale calls throughout the year, however, simultaneous recordings at the Northwest and Southeast Amsterdam Islands detected Indo-Australian pygmy blue whales from February through to May. These areas may be important habitat for blue whales that also use Australian waters, thus highlighting some of the inherent challenges in studying a population that inhabits such a vast area.

There is increasing evidence that blue whales may not all follow precisely-timed annual migrations, rather, the timing of migrations may be staggered throughout the year, and/or some whales may not migrate every year. For example, Antarctic blue whales have been recorded year-round off the Western Antarctic Peninsula, eastern Antarctica102, and off the Crozet Islands in the sub-Antarctic97. Recent research has indicated that there is population of blue whales residing in the Southwest Pacific and Tasman Sea between Australia and New Zealand year round73,81.
At least a proportion of blue whales in the northern Indian Ocean are suspected to migrate longitudinally rather than latitudinally2. This longitudinal movement is between seasonally important areas of high primary productive, which suggest that blue whales do not necessarily fast during the breeding season, especially when combined with evidence from other localities9,91 . Mounting evidence suggests that blue whales select wintering habitat that supports significant biological productivity.

Figure 1. Pygmy blue whale distribution around Australia

Foraging Area           Blue whales are regularly observed feeding on a seasonal basis
(Annual high use area)
Known Foraging Area     Known foraging occurs in these areas but is highly variable both between and within seasons
Possible Foraging Area  Evidence for feeding is based on limited direct