Effects of swim-with-dolphin tourism on the behaviour of a threatened species, the Burrunan dolphin Tursiops australis

摘要

Burrunan dolphins Tursiops australis are frequently targeted by tourism operations in Port Phillip Bay, Australia. This study aimed to provide first insights into whether swim-with-dolphin (SWD) vessels in Port Phillip Bay affect the behaviour of Burrunan dolphins via the use of Markov chain models. The presence of SWD vessels affected dolphinsa?? travelling, foraging, milling and socialising behaviours. The time dolphins spent foraging in the presence of SWD vessels was significantly reduced, with average foraging bout length decreasing by 13.6%, foraging recovery time increasing by 47.6%, and the probability of transitioning from foraging to milling increasing 4-fold. Conversely, dolphins spent significantly more time milling and socialising in the presence of SWD vessels. The reduction in time spent foraging when SWD vessels are present could lead to a decrease in dolphinsa?? rate of energy acquisition, whilst the increase in milling could increase their energy expenditure. Collectively, this may lead to reduced biological fitness with population level consequences. However, although the short-term behavioural budget of the dolphin population was significantly affected, SWD vessels did not significantly affect the cumulative (i.e. yearly) behavioural budget of Burrunan dolphins. Thus, the assumption that boat-based cetacean tourism has major negative effects on targeted populations may be flawed in some cases.