Shark attacks: Why experts are unsure about the exact size of the current white shark population
|Published
The white shark disappearance from some areas in the Western Cape is a mystery. Picture by Leon Muller.
Johannesburg - In April last year Robert Frauenstein headed off to Chintsa East Beach, in the Eastern Cape and disappeared.
A day later on April 14, 2021 his yellow and pink bodyboard washed up on the beach, with bite marks.
A week on and the search for Robert Frauenstein was called off and the 38- year-old became South Africa’s only shark attack fatality for 2021.
From the bite marks left on the board, experts came to the conclusion that Frauenstein was attacked by a large white shark.
The year before, there had been zero reported attacks in South Africa but 2021 also saw two recorded non fatal shark bites.
The attack meant that South Africa followed a trend seen across the rest of the world. Statistics showed that 2021 was a year of increased shark attacks.
Data published by the Florida Museum of Natural History’s International Shark Attack File (ISAF) found that after three consecutive years of worldwide declines, shark bites picked up in 2021.
There were a total of 73 unprovoked incidents, of which nine resulted in fatalities.
Of the nine, there were six confirmed deaths in Australia, New Caledonia and New Zealand. There were single incidents in South Africa, Brazil and the US.
The culprit in most of these attacks was the white shark.
ISAF’s manager Tyler Bowling said in a statement that a portion of the trend probably had to do with beach closures associated with the Covid-19 pandemic.
“The number of unprovoked bites in 2021 aligns with the five-year global average of 72 annually but is in stark contrast to the 52 confirmed bites recorded in 2020, which were the lowest documented in over a decade,” he said, in the statement.
Interestingly Gavin Naylor, the director of the Florida Museum’s shark research programme, suggested that the increase might have also been caused by another reason – that of expanding white shark populations worldwide.
The problem in South Africa is that no one is sure of the status of white shark populations because sightings of the predators have fallen off dramatically, particularly in the Western Cape.
“Between 2010 and 2015 we averaged 250 white shark sightings a year, last year, we had four,” says Sarah Waries, project manager for Shark spotters, a research organisation in the Western Cape that oversees a network of observers that warn when dangerous sharks come close to beaches.
The white shark disappearance from some areas in the Western Cape is a mystery and in the past has even been blamed on orcas targeting the apex predators, so as to eat their livers.
Retired shark researcher, Geremy Cliff believes there is probably more to it than that.
“While the orcas may contribute in some way, I don't think it’s quite as simple as that,” he explains.
“It might be that the sharks might be attracted to go somewhere else because there is more food somewhere else. But I don't think there is any evidence of this.
Or maybe the environmental conditions have changed, where the water might have become warmer or cooler.”
Waries said white sharks that were tagged in 2012 were tracked from the Western Cape up to Madagascar and Reunion Island.
The ISAF did suggest in their report that South Africa might have had more shark attacks in 2021, than was reported.
They pointed out that the number of unconfirmed shark bites in 2021 was high with at least 14 incidents. The ISAF said this had to do with “spotty” reporting caused by overworked first responders and coroners having to grapple with the high number of deaths caused by the Covid-19 pandemic.
Cliff said, however, that this was unlikely the case and the reason for this discrepancy had to do with the way the ISAF gathers information about shark attacks.
“They tend to get their data from the media and unfortunately we have a lot of drownings in this country. They get washed out to sea and the longer the body floats around the ocean, the more chance it’s going to be scavenged,” says Cliff. “And another issue is that the media always tends to sensationalise things. So if someone is bitten by an eel or something, it tends to make the press as a shark.”
And while South Africa might have seen a slight up tick in shark attacks, it is still surprisingly small, says Cliff, when compared to Australia.
But for Waries and the shark spotters who are the eyes above some of the Western Cape beaches, they are looking forward to the return of the white sharks.
“We are definitely missing them,” says Waries.