Over the past years, authorities have reported that great white sharks have slowly disappeared in Cape Town, South Africa. In a published report by the government of South Africa on Tuesday, November 17, they said that the cause of this disappearance might be due to the predators that hunt them.
The disappearance of the great white sharks was first noticed in the coastal sites of False Bay and Gansbaai which was previously blamed on illegal hunting and overfishing, among other causes, Science Alert reported.
When The Predator Becomes The Prey
Great white sharks are usually at the top of the food chain. They are the predators who prey on smaller animals, such as the seals and sea lions. But what if they become the prey instead of the predators?
It turns out great white sharks are one of the favorite food of orcas. The results of the study conducted by the local government suggest that the orcas are the most likely culprit of the disappearance of great white sharks in Cape Town after they saw a couple of whale sharks in the area in 2015.
According to them, orcas specialized in hunting great white sharks, and their appearances in the site usually abundant of great white sharks tell them that they have caused the decreasing number of sharks in Cape Town.
Of course, it is hard to know the exact number of the great white sharks, but spotters initially reported a decline in number in 2017 and then an extended absence in the following years.
Moreover, they also reported that the remains of sharks that washed ashore in the Gansbaai area in 2017 were killed in the same fashion this year. They said that there could be more carcasses of sharks killed in the same manner that was not yet seen.
Alison Kock, a marine biologist at the Cape Research Centre, said that there are obvious drops and gaps in white shark sightings every time this happens and they still do not have the answer.
Great white sharks are considered to be one of Cape Town's assets as tourists flock there to view sharks from the boat or experience being inside the lowered cages to see them closely.
Orcas Love Shark Livers
Kock said that when the shark carcasses washed ashore in 2017, her team performed necropsies on the bodies which were all intact except for the neat tear between the pectoral fins of the sharks. Apparently, orcas know where is exactly the shark's liver is located and ate the organ.
They believe that orcas were responsible for these deaths given the similarities they have with the sevengill carcasses they first saw. Besides, a 1997 video footage of an attack that happened in California suggested that orcas may have similarly worked together to kill great white sharks.
According to the National Geography, orcas target shark livers most likely because they are high in fat and delicious. That behavior is similar to how humans consume butter, bacon because they love fatty foods. Shark liver is also great at maintaining buoyancy and a substantial meal that is up to 600 pounds of meat.
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