Gansbaai, South Africa — Sharks have taken a big hand in the fortunes of this fishing village on the southernmost coast of Africa.
Fishing used to be the lifeblood of Gansbaai (meaning Goose Bay), and to an extent it still is. But nowadays some of the smartest boats slipping out of its rudimentary harbor at high tide in the morning bear tourists who want to experience the thrill of close-up encounters with sharks, particularly of the great white variety.
Shark cage-diving has become big business, luring visitors from all parts of the world. It is also carried on along other parts of the South African coast. But the reason for Gansbaai’s success in particular is that the bay it overlooks is claimed by marine biologists doing research there to have the world’s biggest year-round concentration of great white sharks.
The bay is situated not far from the continent’s southern extreme of Cape Agulhas, regarded as marking the point where the Indian and Atlantic oceans meet. It is not much more than an indent on the outer lip of sizable Walker Bay that is lined by large tourist towns that have whale watching among their biggest attractions.
But the people of Gansbaai say they have dubbed their cove Shark Bay because of its high concentration of sharks. The tourist boats, as with the fishing trawlers, have to depart and return when the tide is in to avoid scraping the rocks along the floor of the shallow harbor mouth. But on any clear day the number of tourist boats riding the inlet’s swells shows why the locals chose to give it that name.
Exactly why great whites in particular favor that spot is not clear. But Alison Towner, a marine biologist at the University of Cape Town who does shark research in the bay, says it is most likely because of the area’s large number of seals, fish and smaller shark species that all form part of their staple diet.
The bay has two islands, one of which is Dyer Island, a low-level rocky outcrop of about 50 acres, or 20 hectare, where conservationists are engaged in a major effort to save a breeding colony of African penguins. The colony has dwindled from 150,000 breeding pairs in 1956 to a mere 900 today, mainly because the removal of guano for use as fertilizer has left them unable to burrow deep enough to protect their eggs and chicks against the seagulls and to shield themselves against the baking sun. (Read my related blog post: African Penguin Colony at the Edge of Extinction.)
Right next to Dyer is Geyser Rock, a much smaller island that teems with seals, which also prey on the endangered penguins. The sharks make their contribution to relieving the endangered birds’ plight by in turn feeding on the seals, thus keeping their numbers in check. The narrow strip of water separating the two islands is called Shark Alley for the way the great whites simply cruise through to help themselves to seals. “It is like a fast-food takeaway,” grins Towner. (See the related blog post: Sky Sharks: Pictures of Super-Predators Snatching Prey From the Air.)
Shark cage-diving is done in a metal enclosure fixed to the side of the boat in the water. Tourists get fitted with wetsuits and dive masks and one after the other get into the cage where they hold on to a bar, their heads above the surface. A mixture of fish parts and oil gets pumped into the water in a process called chumming to lure the sharks.
Safely within their cage, tourists lower themselves under the water surface to peer at the enormous animals as they flash past after a tuna head that is attached to a float and rope that gets cast into the sea from the deck and hauled back in. Sometimes the sharks, often of ten feet (about three meters) or more, provide a special thrill by coming right up to the cage and staring back at the onlookers through the iron bars. Divers are sternly cautioned beforehand not to stick as much as a finger or a toe through the bars.
Not everybody is happy about the practice of luring the animals to boats for the entertainment of tourists. There have been controversies over whether it might cause sharks to attack bathers and surfers in the area.
But Towner says there is little evidence to suggest that the sharks get habituated by the chumming and cage-diving activity as the predators remain in the area for only short periods. They are highly migratory animals. The tourist boat operators make sure as well that the sharks do not get rewarded for their efforts by allowing them to actually grab the bait. Tracking exercises have shown that the sharks simply resume their normal cruising routes once they leave the boats. She is, however, continuing her research to come to a better understanding of the situation.
Towner nevertheless believes that shark tourism actually has advantages. One is that it alerts more and more people to the plight of the animals, which could be hunted and otherwise slaughtered to extinction unless something is done to change attitudes and perceptions created by movies like Jaws, which portray sharks as terrifying monsters . More people around the world are electrocuted by bread toasters than are killed by sharks, Towner points out.
As with most shark species, the great white (Carcharadon carcharias) is under growing pressure and is listed as “Vulnerable” by the International Union for the Conservation of Nature.
Towner and her team do their research from a 9-meter (30-foot) boat named Lwazi, which she says means “seeking knowledge” in the local indigenous isiXhosa language. They also collect data from a powerful cage diving boat named Slashfin, after a sizeable shark they named because of a deep cut in its dorsal fin that might have been caused by a bite from another shark or by a boat’s propeller. The research is funded by the Dyer Island Conservation Trust.
Towner says another spin-off from shark tourism is that an operator like Marine Dynamics Tours, owner of the boats, allows scientists to carry out research from its vessels. By luring the sharks to the boats, she is able to record the prints of their dorsal fins and other markings and so identify and keep track of them, thereby gaining insights into their movements and habits.
The owner of Marine Dynamics Tours is a colorful character named Wilfred Chivell, who likes to tell how he made a new start with a small shark-watching boat after losing everything – “business, house, wife, the lot” – when his concrete-making company went under during the building industry crash some years ago.
Nothing annoys him more than when people refer to the great white shark as “white death”. It is indeed testimony to his love of nature that he founded the Dyer Island Conservation Trust in 2006, particularly to help revive the island’s African penguin colony. But the Trust’s research and conservation programs are aimed also at the wider marine ecosystem, including the whales and the sharks.
Leon Marshall participated in the shark-watching excursion as a guest of Volkswagen South Africa on the occasion of the company’s donation of two vehicles to the Dyer Island Conservation Trust to help with the transport of its staff and with rescue operations.