A white shark (illustration).

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AP / SIPA

They are nicknamed the "killer whales".

The presence of orcas is undoubtedly at the origin of the disappearance in recent years of the great white shark in certain areas off Cape Town (South Africa), according to a government report published on Tuesday.

Some attributed the phenomenon to hunting, others to the use of drifting fishing nets or even to overfishing.

But the results of studies carried out by a team of nine national and international experts therefore emit another hypothesis.

"There is evidence of a causal link with the appearance of a group of orcas that hunt white sharks," according to the report.

When sharks run away from killer whales

In 2017, the remains of five white sharks killed by orcas were found in Gansbaai (southwest of the country).

Another similarly killed was found on the beach this year, and there could be many more, marine biology researcher Alison Kock, who is part of the panel of experts, demonstrated during the presentation of the report.

"Each time, this was followed by an immediate drop in the number of white sharks" in the region, presumably fleeing the predator, she observed, adding that similar cases have been observed in the United States, off California.

"We do not have all the answers", however, concluded the specialist, recommending further research.

Several endangered species

But the orcas aren't the only ones responsible.

The government has launched an ambitious program to protect sharks, several of which are threatened or endangered.

To fight against their disappearance, the report also recommends improving the fight against illegal fishing and the implementation of best practices in the tourism sector, which derives significant income from activities linked to the presence of sharks.

Specialists identify some 1,250 species of sharks, several of which are already protected.

In South Africa, "14% of shark species are threatened," said Environment Minister Barbara Creecy.

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  • South Africa

  • Orca

  • Animals

  • Shark

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