Ecotourism Doesn’t Affect Whale Sharks

Water-based ecotourism -- diving with sharks, swimming with dolphins, snorkeling with whales -- has gotten big over the past 20 years, and while it's great for the local economies, what is its effect on the animals on display?

To figure that out, Australian researchers examined whether encounters between ecotourists and whale sharks, classified as "vulnerable" on the Red List of Threatened Species, had bad results. They studied whale sharks aggregating at Ningaloo Reef in Western Australia, where up to 500 of them, mostly young males, feed between March and July. Using a photo database of individually identified whale sharks (boat videographers record each whale's sex, size and markings, and send images to the Western Australia Department of Parks and Wildlife), the researchers looked at 2,823 whalemeets- boat encounters between 2007 and 2011.

The good news: Whale sharks aren't fazed by the boats. The researchers discovered that total encounters per whale shark and per boat trip increased over time. On average, whale sharks sighted by boats in subsequent years were encountered earlier, stayed longer, and tended to be spotted by boats more often within a season than sharks that were only encountered in a single year. Whale sharks showed no patterns suggesting boats disturbed them; in the years with more boat trips, whale sharks actually appeared to leave the scene at a slower rate.

The researchers say that individual whale sharks returning to Ningaloo Reef become accustomed to encounters with tourists, and their prior encounters don't stop them from returning. It's unlikely that ecotourism is affecting their breeding or foraging behaviors. Sea temperature and plankton levels have more impact on whether they stay or go. So, when you get wet, you can assume the animals have no problems with you, but keep your hands to yourself.

"Multi-Year Impacts of Ecotourism on Whale Shark Visitation at Ningaloo Reef, Western Australia," by R.L. Sanzogni, M. G. Meekan and J.J. Meeuwig; PLOS One, September 23, 2015; DOI: 10.1371/journal.pone.0127345