Conservation

Since the 1980s, our team has been studying the impact of human activity on the dolphins. More specifically, we studied the impact of provisioning (when visitors offer fish handouts to individual dolphins) on dolphin behavior and survival. Our research demonstrated that calves born to provisioned females had twice the mortality than calves born to non-provisioned females. This was most likely due to over feeding and unregulated feeding. The Department of Biodiversity, Conservation and Attractions responded to our research by changing their feeding policies. Calves were no longer fed and since the changes were implemented in 1995, calf survivorship has dramatically improved (Mann et al. 2000; Mann & Kemps 2003; Foroughirad and Mann 2013).

 Eric Patterson

In addition, it has been shown that aquaculture may have an impact on dolphin ranging and behaviour. These data helped deter expansion of aquaculture in the Shark Bay area, benefiting dolphins and several other important marine species. These data are influencing aquaculture management in other parts of Australia and in New Zealand (Watson-Capps & Mann 2005).

Researcher Lars Bejder has been investigating the long-term impacts of vessel activity on the Shark Bay dolphins. His work has shown that when multiple tour vessels are present in a study area, the dolphin population subsequently declines in abundance in the same area. While such effects may not be catastrophic to the Shark Bay population due to its size and genetic diversity, they are still important to monitor, and can serve as crucial guidelines for the management of more vulnerable populations of cetaceans worldwide (Bejder et al. 2006).

Ewa Krzyszczyk