Mafia Island Whale Sharks

Kilindoni · Mafia Island · Tanzania

Mafia Island lies 130 kilometres south of Dar es Salaam in the Tanzanian channel between the mainland and the open Indian Ocean, and its western coast hosts one of East Africa's most remarkable marine wildlife events. From October through March, the northeast monsoon pushes nutrient-rich water through the shallow channels between Mafia and the scattered islands to its west, triggering plankton blooms that draw whale sharks in numbers that make this one of the continent's premier megafauna encounters. I flew in from Dar es Salaam on a tiny Cessna that bounced onto Mafia's grass airstrip, and the next morning I was in the water with whale sharks. The operation is refreshingly low-key. A wooden dhow-style boat carried six of us to the feeding grounds, where spotters on the bow scanned the surface for the telltale shadows and fin tips. Within twenty minutes, the first shark appeared: a juvenile of perhaps five metres, mouth open and filtering at the surface, its spotted skin dappling in the shallow water's reflected light. The encounters are conducted as snorkeling, with SCUBA prohibited near the sharks. This works well because the animals feed in the top three metres of water, and approaching at surface level feels natural and non-intrusive. I slipped in ahead of the shark's path and watched it approach, the enormous mouth opening and closing in its rhythmic feeding pattern, remoras clinging to its belly, a small escort of cobia trailing behind. What distinguishes Mafia from more established whale shark destinations is the intimacy. There were two boats in the feeding area during my visit. In Mozambique or Mexico, there might be twenty. The marine park authority limits boat numbers and enforces approach rules, and the island's relative inaccessibility keeps mass tourism at bay. The sharks here are predominantly juveniles and sub-adults, ranging from four to eight metres, which researchers believe use these waters as a developmental nursery before moving to deeper oceanic habitat.