Whale Shark Ecotourism at Ningaloo Reef, by Sandra Seipel

It comes as a surprise to some that the largest extant fish species in the world, the Whale Shark Rhincodon typus, is a slow-moving filter feeder. Reaching 40 feet or more in length and fueled by tiny planktonic organisms, the Whale Shark inherently captures the curiosity of tourists. People across the globe come to Australia for many different types of shark encounters, including cage diving with Great White Sharks Carcharodon carcharias, scuba diving with Grey Nurse Sharks Carcharias taurus, snorkeling with various species of reef sharks, and snorkeling with Whale Sharks. While the success of the shark-diving ecotourism industry in Western Australia has climbed over the years, scientists began to question the sustainability of such an industry. Research has been done to answer the question of what possible effects ecotourism could have on these docile sharks and their yearly migration to Ningaloo Reef, a very popular site for both the aggregation of Whale Sharks and tourists. Environmental factors and ecotourism targeting Whale Sharks present potential influences on Whale Shark migration patterns, however, more research is needed to fully understand the impacts of ecotourism on Whale Sharks.

Whale Shark Rhincodon typus photographed at Ningaloo Reef.  Photo by Sylke Rohrlach creative commons Flickr

 Whale Sharks aggregate on the coast of Western Australia at Ningaloo Reef every year between March and July to take advantage of the warm water temperatures and a large peak in food availability brought on by mass coral spawning (Anderson 2014). The high predictability of these aggregations provides the perfect opportunity for a successful nature-based tourism industry. The Whale Shark tourism industry at Ningaloo Reef began in 1989 and the total annual number of tourists have increased from 1,000 in 1993 to over 17,000 in 2011. Between 2006 and 2010 the number of tours increased by 70% and the number of interactions between humans and whale sharks increased by 370% (Anderson 2014). Huveneers et al (2017) conducted a socio-economic survey targeting tourist divers between March 2013 and June 2014 to assess the economic value of shark-diving. They found that in the Ningaloo Reef region, Whale Sharks bring in more income than all other shark-diving experiences in Australia, with an annual economic contribution of 12.5 million dollars. Whale Shark diving brought in the highest number of participants who generated the highest total expenditure (Huveneers et al 2017). The Whale Shark ecotourism industry in Ningaloo Reef has significantly expanded since its origination and has high economic importance to the local community. This successful nature-based tourism industry could be utilized to raise conservation awareness; however, many people question if this industry will affect the natural behavior and movement of the sharks.

The increasing number of interactions is of concern to conservationists. Sanzogni et al (2015) conducted a multi-year study examining the impacts of ecotourism on Whale Shark visitation to Ningaloo Reef, and the results address many of these concerns. There was no evidence found of disruption in the sharks’ natural visitation patterns, and with respect to the number of tourists encounters that the Whale Sharks were subjected to there were no negative trends in total encounters, day of first encounter, encounters per trip, residency time, or rate of departure. Regarding behavioral patterns, it was noted that there may be possible short-term behavioral changes, such as diving when disturbed during feeding and shuddering in response to the touch of snorkelers, but there is little evidence of adverse long-term effects on the residency or return of sharks to Ningaloo Reef. With no results supporting significant effects resulting from the interactions between the tourists and the sharks, the results did suggest that environmental factors had a significant influence on the movement of the Whale Sharks.

Variability in oceanic and atmospheric processes have shown to have the biggest influence on the migration patterns of Whale Sharks. Sanzogni et al (2015) also found that southern oscillation index (SOI), sea surface temperature (SST), and chlorophyll a concentration had large influences on Whale Shark movement. Annually, sharks left Ningaloo Reef more slowly and were encountered more often per boat trip when the SOI was high, and increased SST led to less days between encounters per Whale Shark per year. Increases in the total number of encounters per shark per month were associated with high levels of chlorophyll a concentration in the water. This is further supported by the work of Sleeman et al (2010), stating that “changes in productivity associated with the El Nino-Southern Oscillation (ENSO) phenomenon could drive changes in abundance and residency patterns of sharks along the West Australian coast, and at Ningaloo.” Based on these results it is likely that climate change could pose a potential threat to the Whale Shark.

Imagine swimming in front of the mouth of a Whale Shark.  Photo by Sylke Rohrlach.  creative commons Flickr. 

Environmental factors and ecotourism both have potential influences on Whale Shark behavior and migration, but because this is a relatively new area of study much more research needs to be done to understand Whale Shark migration in general. From a tracking study done by National Geographic, it is known that Whale Sharks gather at a few major feeding locations around the world every summer to take advantage of high plankton productivity, from Western Australia and Indonesia to Belize. What drives their movement for the rest of the year and where they go is still unclear. Very little is known regarding mating behavior and reproduction, but it is hypothesized that females migrate to remote islands to give birth where predation is less of a threat (Handwerk 2013). A better understanding of what drives their migration is needed before it can be determined if ecotourism is causing significant changes.

Ningaloo reef is only one of the many Whale Shark ecotourism locations around the world. Tourist operations can be found at almost any location where Whale Sharks are known to aggregate. According to Western Australia’s Parks and Wildlife Service website, Western Australia has strict regulations which require operators of commercial tours to be licensed by the Department of Parks and Wildlife. Interaction protocols have been implemented to control the actions of swimmers and vessels to minimize disturbance to the sharks. These protocols include limitations on the numbers of vessels and swimmers allowed in a specified zone around the sharks, as well as minimum distances that must be kept away from individual sharks. Not all parts of the world have regulations such as these, which are crucial to maintaining a sustainable operation. The creation of international regulations may be critical to the sustainability of the Whale Shark ecotourism industry and to the well-being of these magnificent fish.

References

Anderson, D. J., H. T. Kobryn, B. M. Norman, L. Bejder, J. A. Tyne, and N. R. Loneragan. 2014. Spatial and temporal patterns of nature-based tourism interactions with whale sharks (Rhincodon typus) at Ningaloo Reef, Western Australia. Estuarine, Coastal and Shelf Science. 148:109-119.

Bradshaw, C., B. M. Fitzpatrick, C. C. Steinberg, B. W. Brook, and M. G. Meekan. 2008. Decline in whale shark size and abundance at Ningaloo Reef over the past decade: The world's largest fish is getting smaller. Biological Conservation. 141(7):1894-1905.

Handwerk, Brian. “Secrets of Whale Shark migration revealed.” Nationalgeographic.com. https://news.nationalgeographic.com/news/2013/08/130821-whale-shark-satellite-tracking-migration-gulf-mexico-science/ (accessed April 22, 2018).

Huveneers, C., M. G. Meekan, K. Apps, L. C. Ferreira, D. Pannell, and G. M. Vianna. 2017. The economic value of shark-diving tourism in Australia. Reviews in Fish Biology and Fisheries. 27:665-680.

Parks and Wildlife Service. “Whale Shark management in WA.” dpaw.wa.gov.au.

https://www.dpaw.wa.gov.au/plants-and-animals/animals/whale-sharks?showall=&start=2 (accessed April 22, 2018).

Sanzogni, R. L., M. G. Meekan, and J. J. Meeuwig. 2015. Multi-year impacts of ecotourism on whale shark (rhincodon typus) visitation at Ningaloo Reef, Western Australia. PLoS One [ E0127345] 10(9).

Sleeman, J. C., M. G. Meekan, B. J. Fitzpatrick, C. R. Steinberg, R. Ancel, and C. Bradshaw. 2010. Oceanographic and atmospheric phenomena influence the abundance of whale sharks at Ningaloo Reef, Western Australia. Journal of Experimental Marine Biology and Ecology. 382(2):77-81.