Dear Marmamers,
We are happy to announce the following publication:
Steckenreuter, A., Möller, L., Harcourt, R. (2012). How does Australia’s largest dolphin-watching industry affect the behaviour of Indo-Pacific bottlenose dolphins? Journal of Environmental Management 97: 14-21.
http://www.sciencedirect.com/science/article/pii/S0301479711004002
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 – 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.
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Regards,
Andre Steckenreuter
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PhD Candidate
Marine Mammal Research Group
Graduate School of the Environment
Macquarie University, 2109 NSW, Australia
Ph: 0410862189
Email: andre.steckenreuter@mq.edu.au
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