Great white sharks have largely disappeared from the coastal waters surrounding Cape Town, South Africa [1, 3].
The disappearance of these apex predators disrupts the marine food web and threatens the local economy, particularly the tourism industry reliant on shark sightings.
Researchers said the decline of the Carcharodon carcharias population in the Cape coastline has occurred over the last 10 years [1]. This trend has left a void in one of the world's most famous shark habitats, sparking a debate among marine biologists regarding the primary cause of the exodus [1, 2].
Some experts said increased predation by killer whales, also known as orcas, is the main driver of the decline [1]. These larger predators are known to hunt great whites, potentially pushing the sharks out of their traditional hunting grounds to avoid predation [1].
Other experts said the shift is due to human activities [2]. These factors include the impacts of commercial fishing and the pressures of the tourism industry, such as cage-diving operations [2]. The tension between these two theories highlights the complexity of tracking migratory apex predators in an environment facing multiple stressors.
While the sharks have vanished from the immediate coastal areas of Cape Town, it remains unclear if the population has migrated to deeper waters or if the numbers have decreased globally [1, 3]. The lack of consensus among scientists suggests that the decline may be the result of a combination of both biological competition and anthropogenic pressure [1, 2].
“Great white sharks have largely disappeared from the coastal waters surrounding Cape Town”
The disappearance of great white sharks from a key ecological hub indicates a significant shift in marine hierarchy. If orcas are the primary cause, it suggests a redistribution of apex predator dominance in the Atlantic and Indian Oceans. If human activity is the driver, it underscores the fragility of shark populations to industrial and recreational interference, potentially necessitating new conservation policies for South African waters.
