Document ID: chunk:federal_register_of_legislation:F2013L00289:body:0:p4
Version: federal_register_of_legislation:F2013L00289
Segment Type: other
Provision Reference: 
Character Range: 12415–15496

is important to note that the increase has not been consistent across the population range and some population segments remain at greater risk than others.

Southern right whales occur only in the southern hemisphere. They have a circumpolar distribution between latitudes of 16°S and 65°S. The Australian southern right whale population differs from other populations on mtDNA haplotype frequencies, although nuclear genes show little differentiation between Australian and New Zealand populations. In Australian coastal waters, southern right whales occur along the southern coastline including Tasmania, generally as far north as Sydney (33°53'S, 151°13'E) on the east coast and Perth (31°55'S, 115°50'E) on the west coast. There are occasional occurrences further north, with the extremities of their range recorded as Hervey Bay (25°00'S, 152°50'E) and Exmouth (22°23'S, 114°07'E). In coastal areas, southern right whales generally occur within two kilometres off shore and tend to be distinctly clumped in aggregation areas.

Figure 1: Coastal aggregation areas for southern right whales

Southern right whales in south-western Australia appear to be increasing at the maximum biological rate but there is limited evidence of increase in south-eastern Australian waters. Until recently, southern right whales in Australia were considered to be one population. Preliminary data suggest that south-eastern and south-western Australian right whales may represent distinct matrilineal genetic stocks. This idea is supported by their differential recovery rates. The two Australian southern right whale populations differ from other populations on mtDNA haplotype frequencies, although nuclear genes show little differentiation between Australian and New Zealand populations.

Calving takes place very close to the coast in Australia, usually in waters less than 10 metres deep. Nursery grounds are occupied from May to October. Female-calf pairs generally stay within the calving ground for 2–3 months. On average, southern right whales have a single calf every three years. Gestation lasts 12 months, lactation at least 7–8 months with weaning complete within 12 months. Female southern right whales show calving site fidelity, generally returning to the same location to give birth and nurse offspring.

Other population classes stay in the calving grounds for shorter and variable periods. There is substantial movement along the coast indicating that connectivity of coastal habitat is important. The general absence from coastal areas of reproductively mature females in virtually all years between calving indicates that not all whales migrate to the coast each year. The winter distribution of these whales is unknown but may include offshore habitat where mating occurs.

Southern right whales from Australian populations probably forage between about 40°S and 65°S, generally south of Australia. In the region of the Sub-Tropical Front (41–44°S) they mainly consume copepods, while at higher latitudes (south of 50°S) krill is the main prey item. Right whales feed by