WA Sperm whale numbers not recovering Researchers say there is no evidence of a recovery in sperm whale populations off Western Australia’s south coast, more than 30 years after they became a protected species. “I mean their reproductive recovery rates are pretty slow but we still would have predicted that at least they would have been holding their own. “I think we need to get out there urgently and have another look.” Off the Western Australian coast, where the continental shelf slopes less steeply, Sperm Whales appear to be less concentrated close to shelf edge and more widely dispersed offshore. However, Sperm Whales will oddly concentrate in particular places, like a narrow area only a few miles wide at the continental shelf edge off Albany. Similar concentrations of Sperm Whales have been found elsewhere in Australia, such as south-west of Kangaroo Island. In the colonial era these concentrations made it much easier for whalers to severely dent their numbers. The greatest Sperm Whale catches have occurred since the ‘modern’ era of whaling with engine-powered whaling vessels, harpoon guns and other technical aids. They killed approximately 900 000 Sperm Whales. Whaling ceased off the Albany coast in 1978 but in 2009, the number of sperm whales spotted was much lower than at the end of the whaling era. The current population is about 32% of the pre-whaling level and is therefore considerably depleted. It is possible that Sperm Whales, in Australian waters, occur in severely fragmented populations. The complex social structure of Sperm Whales may increase the potential for loss of particular subpopulations and their associated genetic diversity and social culture. But before we lose too much sleep, overall, the Sperm Whale remains the most abundant of the large whale species. Sperm Whales have been recorded from all Australian states Females and young male Sperm Whales are restricted to warmer waters, while older males travel to and from colder waters and to the edge of the Antarctic pack-ice.