Killer whales live up to their name in Cape’s ‘drive-thru shark McDonald’s’
Orcas leave a trail of corpses on their relentless hunt for fresh, nutrient-rich shark livers along Cape coast
A deadly duo of killer whales is on the hunt again off the Cape coast, satiating their appetite for shark livers and leaving a trail of corpses in their wake.
Port and Starboard, a pair of male orcas that have frequented the Cape coast since 2015, are believed to have killed five female sevengill sharks that washed up in Betty’s Bay last week.
“We think one of the orcas will grab a pectoral fin, and flip the shark over to induce a state of immobility,” said Meaghen McCord, director of the South African Shark Conservancy.
“The other orca will move in and grab the other fin. They pull the pectoral girdle apart, and then suck the liver out.”
The orcas specifically seek out the massive livers, which contain fat, vitamin A and oils, and precisely cut between the pectoral fins, leaving all other organs intact.
“The liver is incredibly nutritious,” said McCord. “The orcas clearly know that it is the most nutrient-rich organ to feed on.”
Port and Starboard are thought to have first struck four years ago in False Bay, and again two years later in Gansbaai, resulting in the deaths of at least 12 sevengill sharks. While they have never been caught in the act, all the sharks found ashore show the same wound patterns, with their livers ripped out.
“They [Port and Starboard] are the only ones that have been documented in the areas that the sharks have washed up,” said McCord.
Sevengill sharks, also known as cowsharks, are alpha predators and most plentiful in False Bay, where tourists could previously see up to 70 at any given time.
“It’s a drive-thru shark McDonald’s,” said McCord. “Once they’re in these areas where sharks naturally aggregate, why would they go anywhere else?”
As the killer whales threaten the top of the food chain, the shark population in the area has declined since 2015. Some sharks flee to Mossel Bay or other deeper waters, and take their time returning.
“When there haven’t been recent [orca] sightings, they start slowly coming back, certainly not in the same numbers, and seem to be frightened,” said McCord. “There’s a huge trickle-down impact on the ecosystem.”
Mysteries surrounding the elusive attackers seem to make the assaults unavoidable.
“Historically, orcas have been found in our waters but further out,” said McCord. “Changing environmental conditions can be driving the orcas closer to shore, but no one knows for sure where they’re from.”