Orcas Are Doing Precise Surgeries on Great White Sharks
Earlier this month on the coast of South Africa a 4.9m female Great White Shark washed up in Gansbaai, a fishing town at the very bottom of Africa.
A team of experts went out to dissect the shark, who’s the largest to wash up since 2012.
“We estimated her weight at 1,110kgs.” said Alison Towner, white shark biologist for the Dyer Island Conservation Trust on the Sharkwatch SA Blog.
“Again there is much speculation flying around about Orcas killing the shark. There is a gaping wound on the sharks underside but until we have examined the injuries closely we cannot confirm if her death is indeed Orca related or not.”
It’s only the fifth shark carcase to wash up in the area. But shortly after the team received reports of two more carcases washing up in the area, although they were unable to locate them. They weren’t to be left waiting for long though. The next day they got a callout and retrieved a 3.4m male who’s missing big pieces out of each flank. While the body was degraded to a point where many of the measurements they’d make during an autopsy were impossible to do, the team were able to ascertain that it was missing its entire liver and heart.
Another two days proceed and another Great White has washed up an hours drive east at Struisbaai. These sightings are coming a little too often now. He’s a 4.2m male, and his wounds match those of the last two that washed up.
“It seems likely that orcas are again the cause of death but we will confirm after the autopsy.” said Alison Towner. “Obviously this is a very sad time for us all, nature can be so cruel and the dexterity these enormous animals are capable of is mind blowing, almost surgical precision as they remove the squalene rich liver of the white sharks and dump their carcass”
With support from Marine Dynamics biologist Kelly Baker, Towner performed her 3rd autopsy in a week, and hopefully the last. The sharks liver had in fact been removed, however unlike the first two carcases, his heart remained. This is the first evidence of Orca predation observed in South Africa.
The team concluded that all three had been killed by Orca by the removal of their livers.
“These observations are unprecedented” says Alison Towner.