How does Australia’s largest dolphin-watching industry affect the behaviour of a small and resident population of Indo-Pacific bottlenose dolphins? Andre Steckenreuter a, * , Luciana Möller a, b , Robert Harcourt a a Marine Mammal Research Group, Graduate School of the Environment, Macquarie University, Balaclava Rd, Sydney, New South Wales 2109, Australia b School of Biological Sciences, Flinders University of South Australia, Adelaide, South Australia 5001, Australia article info Article history: Received 13 December 2010 Received in revised form 19 October 2011 Accepted 3 November 2011 Available online 24 December 2011 Keywords: Dolphin-watching Indo-Pacific bottlenose dolphin Boat impact Marine park Conservation Management abstract The small, genetically distinct population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Port Stephens, New South Wales (NSW), is the target of the largest dolphin-watching industry in Australia and is located within the Port Stephens e Great Lakes Marine Park that was created in 2005. The effects of this industry have been identified as of significant management importance by the Marine Parks Authority NSW. Accordingly, the impact of commercial dolphin-watching boats was investigated from boat-based surveys from August 2008 to August 2009. Presence of dolphin-watching boats altered both the dolphins’ behavioural states and activity budgets. Dolphins spent 66.5% less time feeding and 44.2% less time socialising, spent four times more milling, and were never observed to rest in the presence of dolphin-watching boats. Moreover, dolphin groups were more cohesive during dolphin-watching boat encounters and dolphins tended to avoid tour boats. These effects were exacerbated as the number of boats increased and the distance from boats decreased. The rate of approach was high with boats approaching each dolphin group three times per day in winter and six times in summer. Moreover, groups of dolphins with newborns were approached closer than state regulated minimum approach distances in nine out of ten encounters. Globally, dolphin-watching industries frequent small resident groups of coastal dolphins and effects are likely to be similar. We suggest that existing controls are inadequate and that these together with additional regulations be enforced by a regular presence of authorities. We suggest no more than one dolphin-watching boat within 50 m of a group of dolphins, or 100 m if calves are present. Operating times of dolphin-watching boats should be restricted in numbers after 1pm, i.e., during preferred foraging times for dolphins. Additionally, exclusion zones should be considered to reduce pressure on dolphins undertaking critical activities such as feeding and resting. We recommend monitoring the effectiveness of new regulations that are incorporated in the reviewed marine park management plan in 2012 for a period of three years. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction The coastal habits of many cetacean species, combined with continued human population growth and development in coastal areas (Crossett et al., 2004), has resulted in many cetacean pop- ulations being increasingly exposed to anthropogenic threats (Constantine et al., 2004; Nowacek et al., 2001). One potential threat is the increased exposure of dolphin and whale populations to high levels of boat-based tourism and any concomitant distur- bance (e.g., Bejder et al., 2006b; Gregory and Rowden, 2001). Australia is a hotspot of the whale- and dolphin-watching industry, with more than 1 600 000 national and international participants each year and a high rate of growth averaging 8.3% per annum between 1998 and 2008 (O’Connor et al., 2009). Within Australia, coastal dolphin-watching is common year round in areas where resident populations of bottlenose (Tursiops spp.) and Indo- Pacific humpback dolphins (Sousa chinensis) occur, and seasonal whale-watching on migrating humpback (Megaptera novaeangliae) and southern right whales (Eubalaena australis) also often includes dolphin-watching (O’Connor et al., 2009). Bottlenose dolphins are the most targeted species by far, not only in Australia but also other areas around the world (e.g., Bejder et al., 2006b; Constantine, 2001; Lusseau and Higham, 2004). While there are many common elements in practice, the legis- lation and therefore management of cetacean-based tourism varies throughout the world. In Australia, the Environment Protection and Biodiversity Conservation Act 1999 (Department of the Environment, Water, Heritage and the Arts, 2009) regulates actions that address significant impacts on all listed threatened and migratory species, * Corresponding author. Tel.: þ61 2 9850 7982; fax: þ61 2 9850 7972. E-mail address: andre.steckenreuter@mq.edu.au (A. Steckenreuter). Contents lists available at SciVerse ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman 0301-4797/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jenvman.2011.11.002 Journal of Environmental Management 97 (2012) 14e21