In the sea, sharks are on top of the food chain but that perception is no longer the same and is proven by killer whales.
In South Africa, False Bay has been the playground and breeding place of seals. This is the main reason why aside from killer whales and sharks, specifically great whites, patrol the area waiting for the sumptuous meals to come to them. Seals are enriched with fat that sharks love to fuel their system for a long journey – birthing and search for food.
We use to believe that sharks are on top of the food chain. However, it seems that there are some changes courtesy of the killer whales. In 2015, reports emerge that killer whales preyed on sharks. The incident was unveiled when scuba divers discovered several lifeless broadnose seven-gill sharks within the Table Mountain National Park marine protected area. The site accommodates a massive group of broadnose seven-gill sharks.
The reason for the sharks’ demise cannot be ascertained at first since no dead specimen was retrieved to be examined. It was believed that it could be done by either humans, great white sharks or even killer whales. With the months that followed, more dead sharks were discovered. This time, the culprit has been finally identified – the killer whales.
During the time of the dead sharks’ discovery, a whale watching booking in the area recorded the appearance of two new killer whales in January 2015. The killer whales were easy to distinguish because of their distinctive bent over dorsal fins. The two marine species were nicknamed “Port” and “Starboard” and were spotted close to the seven-gill aggregation site in 2015 and 2016 when the incident happened.
The same two killer whales were also held accountable for the slaughter of five great white sharks in 2017 beyond the coast in Gansbaai. The wound pattern was found to be the same with the seven-gill sharks, with livers missing. Based on the examination of the dead sharks, there are huge extending wounds between the pectoral fins where livers were found missing. Other internal organs such as the stomach, reproductive organs, and heart were left intact.
The bite marks found on the pectoral fins of the shark carcasses clearly belongs to a “flat-toothed” killer whale. No other bite marks were found around the body except for the pectoral fin which was ripped open to get the liver. The killer whales feasted on the fat-enriched internal organ.
Researchers worry that this event could result in a natural drop in shark species in the area. Sharks play a major role in the ocean food chain and act as vital predators keep diverse and healthy ecosystems.