Ecotourism effects on the interactions between white sharks and Cape fur seals around a small island seal colony

This thesis examines the effects of a provisioning ecotourism operation on the behaviour of white sharks Carcharodon carcharias and their prey, Cape fur seals Arctocephalus pusillus pusillus, around a small island seal colony in South Africa. In the absence of human activity, adult seal tactics appear evolved to minimize predatory risk from the sharks, whereas shark tactics do not seem to consider adult seal availability. Pup seals, however, often behave in a manner which leaves them at substantial risk, and shark tactics appear influenced by this behaviour. The system is probably not affected by ecotourism, which seems to have a relatively minor effect on the movement patterns of most sharks. The result is that shark predatory pressure on the seals likely remains at near constant levels during ecotourism activity, and thus that white shark ecotourism probably has little effect on seal behaviour, or on the remainder of the ecosystem.