The world’s largest sharks have a haven near Tanzania

MAFIA ISLAND :: TANZANIA

With its cartilaginous body and cold blood, the whale shark is decidedly not a whale. But this shark is about as long as a humpback and just as gentle. So gentle, in fact, that tours to dive with whale sharks have popped up around the world.

On Tanzania’s Mafia Island, WWF works with WATONET, the Whale Sharks Tour Operators Network of Tanzania, to develop sustainable standards for the industry, implement an ethical code of conduct for swimming with the behemoths, and raise awareness about the need to protect them. And it’s paid off. Whale shark numbers here have more than doubled since 2012.

But these sharks are disappearing elsewhere. Whale sharks travel vast distances in pursuit of plankton and to mate, making them especially vulnerable to ship strikes and entanglement in fishing gear. Today, nearly half of all migratory species are in decline, and whale sharks are among them, according to a 2024 UN report.

“Mafia Island’s entire community has united to protect whale sharks,” says WWF-Tanzania’s Modesta Medard. With the right support, she adds, “we can achieve a future in which the voices, ideas, and visions of those who live closest to nature are at the center of the global conservation movement.”