‘Awe-inspiring and harrowing’: how two orcas with a taste for liver decimated the great white shark capital of the world
A decade ago, up to 1,000 of the apex predators lived in one South African bay. Now they have gone, fleeing from killer whales. But the gap they have left creates problems for other species
T he first carcass of a great white, a small female, washed up in South Africa on 9 February 2017. The 2.6-metre-long body had no hook or net marks, ruling out human involvement. Whatever had killed her had vanished. So too had all the other great white sharks in Gansbaai on the Western Cape, Dr Alison Towner noticed.
“We had several sharks acoustically tagged, and later realised three had moved as far as Plettenberg Bay and Algoa Bay, more than 500km [300 miles] east,” says the Rhodes University marine biologist.
It was not until May that sightings of the sharks returned to their peak. Then three more carcasses were found over five days, followed by a fifth in June. For eight eerie weeks, not one great white shark was sighted.
Gansbaai had a population of 800-1,000 great white sharks in the 2010s, but with each killing the bay’s sharks fled for longer and returned in smaller numbers. When a sixth carcass appeared in June 2021, they did not return for another year.
