Eco-tourism might upset whale sharks

Eco-tourism could be changing the behaviour of whale sharks, according to a team of UK and Mexican researchers.

A study published in Scientific Reports, says whale sharks (Rhincodon typus) exhibit more disturbed behaviour in the presence of a human swimmer.

This is a problem, as according to the International Union for the Conservation of Nature, more than a third of shark and ray taxa are facing extinction, thanks to overfishing, habitat destruction and climate change.

Eco-tourism is supposed to help with shark conservation by improving public awareness and generating revenue. In 2013, a paper valued the shark eco-tourism industry at US $314 million per year.

But there have also been concerns raised by researchers that human interaction with sharks might change the animals’ behaviour, with downstream ecological consequences.

Researchers used a drone to record overhead video footage of whale sharks in the Bay of La Paz, Mexico. They analysed 19 videos where the sharks were swimming alone, and 20 where a single person entered the water and swam alongside them.

The person “mimicked typical ecotourist behaviour, swimming parallel to the shark with a minimum distance of two metres between them and the shark at all times”, according to the paper.

The researchers found that the sharks subtly displayed more disturbed behaviour when a person was swimming with them, moving around more rapidly.

This has an ecological consequence, according to the researchers: if the sharks are expending more energy than usual, they may not be as ready to forage or reproduce.

“In light of these results, we suggest that the initial behavioural state of individuals must be assessed prior to in-water ecotourism activities, and that regulations regarding the minimum distance between human and shark should be revisited and reviewed in detail,” conclude the researchers in their paper.