The Shark Hunt

by Gibbs Kuguru

In the Maldives, Blacktip Reef Sharks have recently displayed peculiar skin spots that bear a striking resemblance to a skin disorder called Leucism. Leucism is a genetic trait that affects the production of melanin pigment in animals, resulting in a partial or complete loss of coloration in their eye, hair, or skin tissue. As a result, animals with Leucism often exhibit a pale or white appearance, with their eyes and other features retaining their natural color. This condition can occur in various species, including mammals, birds, reptiles, and fish. While leucism may make affected individuals stand out from their peers, it does not always cause significant health issues. You might think this is just albinism, which is a total loss of melanin caused by a deficiency of an enzyme (Tyrosinase) which plays a key role in the melanin producing pathway. However, leucism is linked to a cell in dysfunction, called a melanocyte. You can think of a melanocyte as a type of nerve that regulates the production of melanin pigment. Remarkably, evidence suggests that melanocytes are also involved in crucial processes that enable proper motor, sensory, and immunological functions; and that’s where it gets a bit worrying. Our mission: catch these fish and get a skin sample. Simple enough, right?

Having previously been outsmarted by Blacktip Reef Sharks, I was well aware that this task required a precise sampling protocol and generous portion of luck. While we were eventually able to reliably sample these sharks in the past, their Leucistic counterparts continued to evade us. Everywhere we went, rumors of these animals circulated among marine enthusiasts and local fishers, but every story we heard was a tale of rarity. Despite being equipped with all the right tools, we knew we could only push through with tireless determination. So, we grinded.

As the sun began its descent, we gathered on Dhiffushi, a local island, for a shark sampling adventure. Armed with fishing rods, sampling gear, drones, and a contagious sense of excitement, we set out for the long night. Sean “Ginger Beast” Laughlin threw the drone up and began running transects up and down the beach looking for sharks. He eventually found a large aggregation at the north eastern corner of Dhiffushi Island, so we rushed there and set up our sampling station. The first cast was made by Walker Nambu and anticipation hung in the air. The line soared through the sky, gracefully landing amidst the shark stack. Time seemed to slow as we waited, eyes fixed on the shoal, eagerly anticipating any sign of a nibble. Suddenly, the rod twitched and Walker calmly stated, “We’re on.” The line strained and with a swift motion, Walker skillfully maneuvered, reeling it in inch by inch. As the shark got closer, its skin seemed to shimmer like gemstones and we knew that this was the one. The first Leucistic Blacktip Reef Shark caught on record by Walker Nambu! Cheers erupted as the fish emerged from the water. Myself and Mike Bruines prepped the shark for sampling, obtained our tissues and data, and carefully inserted a tag. Seamlessly, the shark was released back into its watery domain, carrying our tag inside its belly cavity. The mission accomplished, our data secured, and the shark swimming freely. It was a moment of triumph, a testament to skill, patience, and teamwork. Having these tissue samples in tow gets us one (large) step closer to finding out what is causing these sharks to sport spots.

Every success in my Ph.D project reminds me constantly that victory rarely occurs without collaboration. As Darwin said, “In the long history of humankind (and animal kind, too) those who learned to collaborate and improvise most effectively have prevailed.” I want to thank The Ritz-Carlton Maldives Fari Islands who provided the platform for us to catch these sharks and the team who persevered with ingenuity and grit. Your contributions will not be forgotten. Thank you also to Sharkproject for without whom this project would have never been mounted in the first place!

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Do you have questions about the project? Don´t hesitate to contact our project leader Anke Apelt (a.apelt@sharkproject.org).