Cetacean Society International

Whales Alive!

Vol. VI No. 3 July 1997


The Bottlenose Dolphins of Northland, New Zealand:
A Population Impacted by Swim-With-Dolphin Tourism

by Rochelle Constantine, School of Biological Sciences,
University of Auckland, New Zealand


Little is known about the abundance and behavioural ecology of bottlenose dolphins (Tursiops truncatus) in New Zealand waters. Research has been conducted on only two populations in New Zealand's coastal waters i.e., the Bay of Islands, North Island and Doubtful Sound on the South Island. The coastal habitat use of bottlenose dolphins brings them into frequent contact with humans, making them vulnerable to habitat degradation and behavioural disturbance from contact with recreational and fishing vessels. In addition, bottlenose dolphins are now a primary target of commercial swim-with-wild-dolphin and dolphin-watching tours.

There is increasing interest globally in interacting with wild cetaceans. In New Zealand, swimming with wild dolphins is allowed under the Marine Mammals Protection Act 1978, and all commercial operations must have a permit from the Department of Conservation. It is currently possible to swim with either bottlenose, dusky, common or Hector's dolphins in seven different areas along the coastline and dolphin watching is possible in many other parts of New Zealand. The marine mammal based tourism industry in New Zealand is expected to earn in excess of US$10.5 million in direct income by the year 2000, and a projected additional input of US$31-35 million into the local economy. Although this industry has enormous economic potential, the conservation needs of the dolphins must not be compromised. A key aspect to successful balancing of these needs and management of marine mammal based tourism is a knowledge of the target species and population. With the ever increasing demand for permits to interact with these animals, this knowledge is vital.

My Ph.D. research at the University of Auckland focuses on the bottlenose dolphin population of Northland and the impacts of commercial swim-with-dolphin tours on this population. An important step in any management plan is the need to define the limits of the resource. By photographing the nicks and scars on the dolphins' dorsal fins (a technique known as photo-identification), I have been able to identify 300 different individuals using at least some part of the Northland coastline as their home range. Approximately 80% of the adult dolphins I am studying have these markings which makes it possible to assess the population size, individual associations and home ranges of these dolphins.

There are currently six permits issued for commercial operations in two areas along the Northland coastline (approximately 30 miles apart) with a further five applications pending in another three areas. This means the potential for dolphins to be targeted in four of the main six bay areas along the Northland coastline is very likely. But just because people want to swim with dolphins does not mean dolphins want to swim with people. The other aspect of my research involves an assessment of dolphin responses to swimmers and boats associated with the swim-with-dolphin tours. During the course of my M.Sc. research it became apparent that not all dolphins were willing to interact with swimmers. It is possible that individual dolphins will become familiar with boats and choose to increase their approaches to or, conversely develop a cumulative aversion towards them. With the use of photo-identification, the identity and number of dolphins who are willing to interact with swimmers will be determined and changes in responses over time will be monitored.

This three year research project will allow the Department of Conservation to successfully manage this industry with a knowledge of the target population, their home range and the impacts of this form of tourism on the dolphins. Swim-with-dolphin tours give people a unique opportunity to learn about dolphins in their natural environment, but operators and management must maintain a focus on minimising disturbance to the dolphins and ensuring that their welfare is paramount. If this does not happen, then the future well-being of this population may be compromised.

This research would not be possible without the generous assistance of Cetacean Society International, the Department of Conservation and the University of Auckland Graduate Research Fund.


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