Vanishing of sharks hits Cape Town
The fearsome predator has not been seen in False Bay so far this year, and tourism operators are getting worried
Capetonians do not know who to blame for the disappearance of their great white sharks: the orcas that eat them, the fishermen who sell their prey to Australia for use in fish-andchips shops, or gradual ecological change.
Capetonians do not know who to blame for the disappearance of their great white sharks: the orcas that eat them, the fishermen who sell their prey to Australia for use in fishand-chips shops or gradual ecological change.
The biggest predatory fish in the world have not been seen in 2019 in False Bay, according to scientists and cage-diving operators. While the absence may be temporary it is creating concern because, along with vineyards, Table Mountain and world-class restaurants the species is key to the $2.6bn provincial tourism industry.
“It’s unprecedented that they aren’t here,” said Gregg Oelofse, City of Cape Town overseer of coastal management. “To think that they may no longer be here is tragic. They are central to Cape Town’s identity.”
The loss of the two-ton sharks from False Bay, where they are famed for leaping out of the water in pursuit of seals, prompted the city to put out a press release in August noting their disappearance, drawing the ire of state officials.
The sharks support a cagediving industry employing as many as 750 people and a vibrant documentary-making scene. There is concern that many of the thousands of tourists who view sharks off the city’s coast may go ’elsewhere. s beaches 14
Spotters, who began monitoring the city years ago after a series of fatal attacks, have not seen a great white in 2019 after averaging 205 sightings from 2010-2016. Sightings fell to 50 last year. A number of whale carcasses that washed ashore had no shark bites, an unusual occurrence.
The national government criticised the assessment of the municipality. “The department is unable to corroborate the City of Cape Town’s statements. There is a need to focus management decisions on information that is factual and scientifically sound,” it said, adding that cage divers and scientists have seen great whites in the bay.
The three cage-diving operators in False Bay, who lower tourists into the water around Seal Island to view the 4.5m sharks, say they have not spotted any in 2019 and the 40 tagged sharks have not been picked up by sensors in the bay.
The state fisheries department has not released assessments of the impact of fishing on the great white’s prey for several years. Papers written by state scientists noted the increasing scarcity of the sharks and a 2018 study said smoothhound and soupfin types they eat may be overfished.
The department did not respond to questions on the effect of so-called demersal shark long-line fishing that sees small sharks sent to Australia where they are sold as “flake”.
Still, great whites are a migratory species and are more common around the middle of the year in Cape Town. Also, scientists say fish stocks appear to be moving gradually east.
“Great whites are highly migratory animals [and] swim great distances,” said Bernard Seret, a marine biologist who worked as a shark specialist at the French National Museum of Natural History. “If they are still absent a year from now, scientists could start developing hypotheses. It’s much too soon to draw any conclusions.” In 2005, a great white shark — named Nicole after Australian actress Nicole Kidman — that had been tagged in SA, swam to Australia and back.
The arrival four years ago of two male orcas, called Port and Starboard as their dorsal fins are bent to the left and right, may have had an effect. The two hunt large sharks, whose livers they tear out to eat before discarding the rest of the carcass.
There have been instances elsewhere including California’s Farallon Islands where great whites have temporarily left after being preyed on by orcas, according to Alison Kock, a marine biologist at the Cape Research Centre. There is evidence of them eating both great white and sevengill sharks in False Bay, she added.
“Port and Starboard came to the island one Sunday, smashed a few sharks and the sharks didn’t come back for three weeks,” said Stef Swanson, the owner of Shark Explorers, one of the cage-dive companies.
For the cage divers, who charge as much as R3,500 a trip, it is all a disaster.
“With the white shark crisis, many of those clients have cancelled their bookings,” said Swanson, noting that bookings are down 50%. “At the end of the day the client wants to see the white shark. It’s part of their bucket list.”
While the effect on tourism is worrying, scientists and the city’s tourism body, Wesgro, say the impact on the ecosystem could be of greater concern.
Already there have been changes. Seals are swimming more openly away from the island, sevengill sharks have emerged from the kelp forests, and bronze whaler sharks have been seen near beaches.
“White sharks influence hundreds of species in the bay, either through direct predation or by the fear of predation,” Kock said. “Their continued absence will likely result in more ecological changes, many of which we can’t predict.”