Researchers are raising alarms after a troubling pattern has emerged along South Africa’s coastline: Great white sharks — once dominant fixtures of the region — are turning up on shore and, in some areas, vanishing entirely.
What’s happening?
Great white sharks, often framed as unstoppable ocean predators, are quietly retreating from parts of South Africa’s coast. People first pointed to fishing or boat activity, but researchers noticed that two orcas, named Port and Starboard, seem to be nudging the sharks out of their usual haunts, according to a ScienceAlert report.
Since 2017, researchers have documented at least nine great whites found dead along the shoreline with a specific injury — their livers removed. Orcas target the nutrient-rich organ with precision, killing the sharks quickly.
Marine biologist Alison Towner, who led the research, said the behavior forces surviving sharks to flee.
“What we seem to be witnessing, though, is a large-scale avoidance (rather than a fine-scale) strategy, mirroring what we see used by wild dogs,” she explained, per ScienceAlert. “The more the orcas frequent these sites, the longer the great white sharks stay away.”
The effect has been dramatic. Areas once known for reliable great white sightings, including waters near Dyer Island, have seen their presence drop sharply — sometimes disappearing for months at a time.
Why is the decline of great white sharks concerning?
Great white sharks play a critical role in maintaining balance in marine ecosystems. As apex predators, they help regulate populations of smaller sharks and fish.
When great whites pull back, something else takes their place. Along parts of South Africa’s coast, copper sharks are showing up more often, changing which species get hunted — and which don’t. That kind of shift tends to hit smaller fish first, especially ones already under pressure.
The fallout doesn’t stay offshore. Shark sightings help bring in tourists, researchers, and regular income for nearby towns. As sightings drop, so does that activity, leaving some coastal communities with fewer visitors and less support for marine protection.
Ecologists warn that ocean systems are more stable when top predators remain part of the ecosystem. Without them, it can take much longer for things to settle — if they do at all.
What’s being done about it?
Researchers continue tracking predator movements through tagging and aerial surveys, watching to see whether great whites return. So far, the changes appear to be holding.
For people following the story from afar, avoiding added strain on marine ecosystems matters — from paying attention to where seafood comes from to cutting back on plastic that ends up in the ocean.
What’s unfolding off South Africa’s coast isn’t isolated. When a dominant species disappears, the ocean doesn’t rebalance overnight. It adapts — sometimes smoothly, sometimes not — with consequences that can reach well beyond the water line.
Get TCD’s free newsletters for easy tips to save more, waste less, and make smarter choices — and earn up to $5,000 toward clean upgrades in TCD’s exclusive Rewards Club.