Swimming with Giants: the impact of swimming with whale sharks in Mexico

I have traveled to the Yucatan Peninsula of Mexico to find out the impact of ecotourism on the largest fish in the ocean, the whale shark. Whale sharks are known to gather at a dozen major feeding locations around the world, from Western Australia to Indonesia to Belize. But between May and September every single year, the waters of Mexico's northern Yucatan Peninsula draw far more animals than any other place, with up to 400 individual whale sharks in any given season. Whale sharks are filter feeders and they feed on tiny little microscopic plankton in the ocean. They use a technique similar to that of many whales, although of course they are a shark. And it's whilst they're feeding that they're up close to the surface of the water, which is when people have the opportunity to swim with them. And they're such gentle giants that they make the perfect species for people to come and swim with. But it's because of this that tourism is building in the area and around people wanting to come and swim with these species. Which on one side is a really good thing because they are a shark and people often have a misconception about sharks as a species. But on the other hand, with this growing ecotourism we see masses of boats out on the water, loads of people jumping in with the sharks. And this can have an impact on their behaviour in terms of how long they're feeding at the surface, how long they're diving for. And it's unknown yet the impacts long-term this has on their behaviour and their survival as a species. So I'm meeting up with scientist Rafael de la Parra to head out at sea with him to find out more about the technology that he uses to track whale sharks and learn more about their behaviour and how to help them long-term. I am marine biologist Rafael de la Parra and I'm specialised in whale shark biology and ecology. We've been deploying real-time tracking devices in order to follow them after they leave this area. This is a satellite transmitter which we attach and fit to the first dorsal of the whale sharks. The screws go all the way through the dorsal fin. This is not easy. We've been completing several loops on different sharks. The tourism has been impacting the behaviour of whale sharks because when there are too many boats they seem to be reacting and they simply submerge. But at the same time this is allowing us to change the perspective of the general public about the sharks, not only the whale shark but all the sharks. I had two days out at sea with these beautiful animals. The first did not go as planned. It was super choppy out at the water and I was extremely seasick throwing up over the side of the boat so I didn't get much footage at all. Then on Sunday I decided to go back out and try again and it was completely different. The water is crystal clear, perfect conditions. We saw dolphins on our way up to the whale shark spot. Although it was an incredible experience swimming next to the largest fish in the ocean. These animals grow up to 40 feet long and weigh up to 20,000 pounds. They're absolutely massive. So swimming alongside next to them you just feel so small and so in awe of them and watching them move so gracefully and gently through the water is a truly special experience. But for me this experience was somewhat tainted by the masses of boats around us in the water. The constant people jumping in around these animals and the feeling of just wondering the impact that this has on their behaviour and how they may be feeling in this moment. So I really do think that we have a long way to go still in terms of finding the balance between ecotourism and doing what's best for the longevity and the behaviour of these animals.