Eco-tourism could be changing the behaviour of whale sharks, according to a team of UK and Mexican researchers.
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.
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.
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The Ultramarine project – focussing on research and innovation in our marine environments – is supported by Minderoo Foundation.