HABITAT OF WHITE SHARK

White Sharks are uncommon but there are areas in Australian waters where encounters appear to be more frequent. These include; waters in and around seal and sea lion colonies such as Neptune Islands, South Australia and larger solitary sharks in the waters around Dangerous Reef and from the Pages (near Kangaroo Island) to Nuyts Archipelago in the Great Australian Bight and the Recherche Archipelago in Western Australia. Many of the land areas occupied by seals are protected areas but there is a need for threatening activities to be excluded from the marine environment adjacent to the seal colonies.

Studies of Great White Sharks sighted at pinniped colonies indicate that the sharks appear to be largely transient, with a few longer term residents (Klimley and Anderson 1996, Strong et al. 1992). Individuals are known to return to feeding grounds annually on a seasonal basis. A number of studies indicate that some populations appear often to be small and highly localised, with a high degree of site attachment. For example, in one study in the Spencer Gulf area (South Australia), 36 per cent of sharks were resighted always in their original location (Strong et al. 1992). A further study in South Africa found that of 147 Great White Sharks tagged, 30 individuals were resighted a total of 59 times one of which was resighted 10 times. Of the 30, all but two were resighted at the same area in which they were originally observed (Ferreira and Ferreira 1996). The resighting of individual Great White Sharks at particular localities is well documented in other areas of the world (Bruce 1995), such as Western Cape (South Africa) (Cliff et al 1996) and California (Klimley and Anderson 1996).

White Sharks of all sizes occur throughout their Australian range. However, there is a tendency for juveniles to occur in different areas to subadults and adults. Juveniles are most commonly encountered in inshore areas, often in the vicinity of the open coast beaches. The Great Australian Bight, Victor Harbour Coorong region (South Australia), areas off Portland and Ninety Mile Beach (Vic), Garie beach – Wattamolla and Port Stephens – Newcastle (New South Wales) and some areas off southern Queensland appear to be seasonally important for juvenile White Sharks. (Bruce. B, D. Malcolm H. & Stevens J.D. 2001). The areas where juveniles are mostly found are most likely pupping grounds. Pupping grounds may require some seasonal protection between the months of December to June when it is estimated that pups may be born. However, more research on the reproductive cycle of female White Sharks however is needed before concluding more accurately the months of the year that White Sharks reproduce and that these sites are indeed “pupping grounds”.

Research suggests that White Shark populations may segregate according to size and gender, and for reproduction. Strong et al. (1992) found that, in South Australia, the ratio of females to males was 6:1 at Dangerous Reef and other inshore islands, whereas around the offshore islands of the North and South Neptunes it was 1:20. This segregation can fluctuate with location and over time (Strong et. al. 1996).