The presence of orcas, superpredators nicknamed “killer whales”, is undoubtedly at the origin of the disappearance of the great white shark in certain areas off Cape Town, according to a South African government report published on Tuesday, November 17.
Found in South Africa, white sharks have disappeared from some of its coasts in recent years. Some attribute the phenomenon to shark hunting, others to the use of drifting fishing nets or even to overfishing. But the result of studies carried out by a team of nine national and international experts appointed in March by the government, which launched an ambitious program to protect sharks – several species of which are threatened or endangered -, makes 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.
In 2017, the remains of five white sharks killed by orcas were found in Gaansbai (southwest). Another, similarly killed, was found on the beach this year. And they could be many more, demonstrated during the presentation of the report the researcher in marine biology Alison Kock, who is part of the panel of experts. “Each time, this was followed by an immediate drop in the number of white sharks” in the region, probably fleeing the predator, she observed, adding that similar cases have been noted in the United States, off California. “We don’t have all the answers”, however, concluded the specialist, recommending further research.
Shark fishing is a historical sector in South Africa and tourism derives significant income from activities linked to the presence of sharks. To fight against the disappearance of sharks in the country, the report also recommends improving the fight against illegal fishing and better practices in the tourism sector. Experts identify some 1,250 species of sharks, many of which are already protected. In South Africa, “14% of shark species are threatened”, recalled the Minister of the Environment, Barbara Creecy, during the presentation
Each year, 100 million sharks are killed in the world’s seas. A number of captures twice as high as that which would maintain their population at its current level, according to wildlife protection NGOs.