"Whale sharks for the mob," says Kortler. "Much has been discussed about this phenomenon in Oslob, in the Philippines. "If you have never seen a whale shark, this is the place to go; it is 100% guaranteed. In this drone image (shot under licence), you can see the industry behind the tourism - 9 whale sharks approaching boats to be fed, and many more swimmers and divers there to see them. This takes place every day. In my opinion, the interaction has become a circus rather than a celebration of nature."