This small country located on the Horn of Africa may not be known as a mecca for tourism, but its relatively small number of annual visitors ensures a raw and uncrowded experience with the whale sharks that come here to feed in the Red Sea’s plankton-rich waters between November and February. These months also coincide with the spawning events of swimming crabs, whose eggs provide yet another food source for the mainly sub-adult whale sharks that arrive at this time of year. Other marine life that snorkelers may encounter here include whales, dolphins, jellyfish, starfish, sea urchins, sea turtles and nudibranchs (a type of flamboyantly hued mollusc).
The best place to look for the sharks in Djibouti is within the Gulf of Tadjoura, as well as the Ghoubbet-el-Kharab (“Gulf of the Demons”), which is separated from the former by a strait just 1 kilometre long. The Ghoubbet-el-Kharab attained its ominous name by virtue of the strong currents that swirl through the strait. This natural phenomenon brings in vast amounts of plankton from the Red Sea, which forms the base of a food web that supports an abundance of marine life, including whale sharks, which can often be seen close to shore here. The currents also improve visibility underwater, providing favourable conditions for photography, while free diving with the sharks in the company of marine photographer Joshua Barton will ensure you’re in the right place at the right time for the perfect shot.
Our next whale shark hotspot centres around the Rufiji Mafia Kilwa Marine Reserve, which comprises the southern section of Tanzania’s Mafia Island and its surrounding marine ecosystem. It is here that silt deposited from the Rufiji River in mainland Tanzania meets the warm waters of the Indian Ocean, ferrying huge amounts of plankton into the mouths of waiting whale sharks. They can also be seen foraging for shrimp near the surface here.
While whale sharks appear at most aggregation sites for just a few months out of the year, evidence suggests that at least some of those found at Mafia are actually year-round residents. “There aren't too many places where you repeatedly see the same whale sharks,” says Simon Pierce, principal scientist and researcher for the Marine Megafauna Foundation. “These days, it's almost like visiting old friends.”
This unusual behaviour means that the whale shark population at Mafia is among the most well studied of all whale shark populations. Pierce’s “old friends” can be identified via satellite tags and even by distinct physical characteristics. Markings as unique as our fingerprints can be found on a whale shark’s left side, between the gills and the pectoral fin, which once catalogued can be used to identify each individual fish that makes an appearance at Mafia.
Pierce and his colleagues work with local tour operators to ensure sustainable practices here, and it’s clearly working, as the Mafia population grew from 100 sharks in 2012 to 180 in 2017 – a rise of 80%. While the whale sharks can be spotted year-round, sightings are at their best between October and February.
Enshrined as a UNESCO World Heritage Site in 2011, the Ningaloo Coast is a biodiverse marine reserve that is home to one of the longest near-shore reefs in the world, the Ningaloo Reef, which stretches for 160 miles off Australia’s remote northwest coast. In some areas, the reef is less than half a mile from the shore. The whale sharks’ arrival here, which takes place between March and June, coincides with mass coral spawning events that involve more than 300 species of coral.
Due to this marine bounty, UNESCO estimates that 300-500 whale sharks come to feed here each year – among the largest documented aggregations anywhere in the world. The colourful clouds of egg/sperm bundles released by the coral polyps attract astronomical numbers of krill and plankton, which in turn attract the whale sharks. The coral spawning takes place 7-10 days after the full moon in March and April.
The Marine Megafauna Foundation (MMF) mentioned previously is based in the town of Tofo in southern Mozambique, an apt location for scientists whose research subjects include whale sharks and manta rays, both of whom can be reliably found here in the wider Inhambane Bay region. The bay is a critical feeding ground for juvenile whale sharks, as plankton is a constant food source here.
As with Mafia’s whale sharks, there is a significant resident population that live year-round in Inhambane Bay, although the MMF have found that around 70% of the sharks seen here are transient. Sightings are most common between October and March, when visibility underwater is at its best and the sharks can regularly be seen feeding on krill and plankton near the surface. Bear in mind, however, that cyclone season begins to rear its head in February.