Wildlife tourism is a fraught concept, with very good reasons to encourage it and also some important reasons to think very, very carefully about its negative consequences. On the one hand, wildlife tourism injects important dollars into local economies, making animals worth more alive than dead. On the other hand, the constant presence of humans and their cars, trucks, or boats, can lead to highly detrimental outcomes for the animals. Those consequences can be obvious, such as habitat destruction for the creation of roads or viewing spots, or they can be subtler, such as changes in the animals’ daily activity cycles. Perhaps nowhere is the struggle between risks and benefits more evident than with the dolphins of Australia’s Port Phillip Bay.

Some research suggests that when people have a chance to interact with wild dolphins, tourists leave their experience with increased knowledge about the target species and become more likely to engage in conservation-related behavior. And cetacean-based tourism, whether the most immersive “swim with” experiences, or the more distanced “whale watching” is one of the fastest-growing industries worldwide. In 2008, the industry generated a whopping $2.1 billion in 2008, according to Victoria University researcher Nicole E. Filby and colleagues.

In Australia, some 1.6 million tourists participate in dolphin-related tourism each year, bringing more than $29 million into the Australian economy. The benefits of whale- and dolphin-related tourism on human economies are unequivocal, but how do the animals themselves fare? To see, Filby conducted a 15-year-long observational study of the Burrunan dolphins of Port Phillip Bay.

The swim-with industry in Port Phillip Bay began in 1986, and by 1995 the tour operators, together with the Department of Conservation and Natural Resources, joined to create a “code of practice” (COP), which set out guidelines for the responsible behavior of tour boats with respect to dolphins. The COP was later amended in 1998 and became the “Wildlife (Whales) Regulations,” which included specific regulations for the dolphin swim-with industry. Those regulations have been continually amended over time. At the present, there are three tour operators in Port Phillip Bay licensed to run swim-with programs. In all there are four boats that run these operations, and each is allowed to make up to two trips per day.

Burrunan dolphins (Tursiops australis) are a genetically distinct type of bottlenose dolphin, and they’re only found in two spots in Victoria, Australia: Port Phillip Bay and Gippsland Lakes. As resident dolphins, they use the waters off the southern coast of Australia all year long, and since Victoria is highly developed, they’re in close proximity to humans throughout the year, both in the form of tourists and through the shipping industry.

The first set of Filby’s observations took place in 1998-2000. During that time, she was present on 128 swim-with excursions, which included 107 dolphin sightings, with an average of 34.8 minutes per sighting. Her second set of observations took place in 2011-2013. She observed 178 excursions, which included 104 sightings, with an average of 26.6 minutes per sighting. Both the sighting success rate as well as the average length of the sightings had both statistically decreased over the course of 15 years.

Each dolphin “sighting” can be split into a number of discrete “approaches.” There are three main methods for approaching a group of dolphins. The legal one is to motor alongside the dolphins in a path parallel to their own. The two illegal ones involve directly approaching an oncoming pod and a maneuver called a “J” which involves travelling in parallel to the pod, but then pulling out in front of the pod and turning around to block its path. Over the course of her study, Filby documented a statistical increase in non-compliance, with operators becoming more likely to use illegal approaches over time.

It is perhaps not surprising that the overall success of the swim-with excursions decreased as non-compliance increased. “Legal approaches resulted in the highest levels of neutral and approach responses,” write the researchers. “Conversely, dolphins most frequently responded to illegal approaches with avoidance.”

Taken together, Filby and her colleagues discovered that the dolphins have indeed altered their responses to tour vessels over the 15 years of her study. Why did sighting success decrease over time? One possibility is that the dolphins have started to abandon Port Phillip Bay in response to increasing vessel traffic. If that’s the case, that could explain why the remaining dolphins became more likely to approach tour vessels. If the more sensitive animals have decamped for calmer waters, then those that remain may have a more “risk taking” personality, making them more eager to explore boats and swimmers.

However, Filby cautions that an increase in voluntary exploration of tourists does not mean that the animals aren’t still suffering, at least in the long term. That’s because the dolphins were more likely to show an approach response when resting or foraging. By engaging with humans instead, the dolphins may be losing out time that would otherwise be spent on those important biological functions. Resting, for example, is prime nursing time for young calves. Over the long-term, disruptions in feeding and resting could have serious population-level consequences.

Alternatively, it could be the case that the dolphins have simply become habituated to the presence of vessels and swimmers over time. By being less frightened by the presence of boats, the dolphins could have become more susceptible to ship strikes and other anthropogenic forms of harm.

Whatever the mechanism, dolphins have changed their responses to tour operators and tourists, both approaching and avoiding them more often now than 15 years ago concomitant with an increase in illegal approaches. As a result, Filby argues, “non-compliance has negative impacts for both the targeted species and the industry, with illegal approaches result[ing] in more frequent avoidance responses by the dolphins.” That not only has the possible long-term effect of reducing the dolphins’ biological fitness, but also has the immediate effect of decreasing customer viewing opportunities and satisfaction.

There’s a mismatch between the growing, economically valuable industry and the animals on whom that industry relies. That’s because the Burrunan dolphins are listed as threatened under the Victorian Flora and Fauna Guarantee Act, and the Port Phillip Bay population is considered vulnerable to extinction because of a confluence of factors: a restricted home range, the fact that the home range is in close proximity to a major urban center, and female philopatry, which serves to keep the population in tight quarters. Altogether there are only about 120 individuals in the Port Phillip Bay population.

The swim-with dolphin tourism industry in Port Phillip Bay may rapidly grow towards unsustainability, both ecologically and economically, unless the operators rapidly come into compliance. If they aren’t careful, they’ll scare off the very animals upon whom their businesses rely. – Jason G. Goldman | 10 December 2014

Source: Filby N.E., Stockin K.A. & Scarpaci C. (2014). Long-term responses of Burrunan dolphins (Tursiops australis) to swim-with dolphin tourism in Port Phillip Bay, Victoria, Australia: A population at risk, Global Ecology and Conservation, 2 62-71. DOI: http://dx.doi.org/10.1016/j.gecco.2014.08.006

Header image courtesy Nicole Filby