Killer whales hunt white sharks in Mossel Bay, South Africa
Killer whales hunt white sharks – Witnessing a predation event between white sharks and killer whales is an incredibly rare occurrence – until now. In a recent study, researchers observed four orcas hunting white sharks off the coast of South Africa from the air. This behavior has never been seen in such detail before and raises questions about how this new behavior may spread among whales and the potential impacts on shark populations.
Alison Towner, a senior shark scientist at Marine Dynamics Academy in Gansbaai, South Africa was one of the authors of the study. She said that only two killer whales in South Africa had previously been linked to hunting white sharks and neither were seen ‘in action’. However, the authors believe that the involvement of these four new whales suggests the behavior may be spreading.
The study also gives new insights into sharks’ attempts to evade capture by orcas. On two occasions, orcas approached sharks closely and slowly, while the shark, instead of fleeing, stayed close to the orca, keeping it in view – a common strategy that seals and turtles use to evade sharks. However, orcas are social and hunt in groups, and the researchers believe these behaviors may render the circling strategy ineffective for white sharks.
“Killer whales are highly intelligent and social animals. Their group hunting methods make them incredibly effective predators,” said marine mammal specialist and study a
The study, led by marine mammal specialist and author Dr Simon Elwen, Director of Sea Search and a research associate at Stellenbosch University, also confirmed that one infamous killer whale, locally known as “Starboard” was part of the predation event and ate what was suspected to be a large piece of shark liver.
To get a better understanding of the predation event, researchers analyzed drone and boat survey data before and after the incident. While multiple white sharks were recorded on the day of the predations, only a single shark was seen in the 45 days afterwards, suggesting that many had fled in response to the orcas’ presence.
The authors of the study suggest that if more killer whales adopt the practice of hunting white sharks, it could have far reaching impacts on shark populations and ecosystems. “The potential for the spread of this behavior among killer whales is concerning,” said Dr Elwen. “We need to monitor their movements closely to understand how far-reaching these effects could be.”
Dr Alison Kock, a shark expert and marine biologist from South African National Parks added that “We first observed the flight responses of seven gills and white sharks to the presence of killer whales Port and Starboard in False Bay in 2015 and 2017. The sharks ultimately abandoned former key habitats, which has had negative consequence for both the ecosystem and shark-related tourism.”
This suggests a potential need to find ways to minimize the impact of killer whales on white sharks, as well as better understand why they have started targeting them. Monitoring their movements and assessing potential mitigation strategies could be essential for protecting white sharks in False Bay and other areas where predator-prey interactions are observed. The research team is now working on further projects to better understand the behaviour of both killer whales and white sharks in South Africa. Such work can help inform conservation strategies aimed at protecting shark populations.
The study was published in the journal Marine Biology. It is available online here: https://link.springer.com/article/10.1007%2Fs00227-020-03837-4 . The research team involved Dr Simon Elwen, Alison Towner, Dr Alison Kock and Philippe Bester of the Dyer Island Conservation Trust; Dr Mariana Fuentes from Murdoch University in Australia; and Dr Els Vermeulen of Stellenbosch University and Marine Dynamics. They were supported by Sea Search, Marine Dynamics Shark Tours and the Save Our Seas Foundation.
In conclusion, white shark predation by killer whales is a relatively new phenomenon and has implications for conservation efforts. Understanding the behaviors of both species will help inform strategies to protect white sharks in False Bay and other areas where they are targeted by killer whales. Additionally, further research is needed to understand how far-reaching this behavior may spread among killer whale populations.
References:
– Elwen, S. et al., 2020. Killer whales predation on white sharks in False Bay, South Africa is more than a one-off event. Marine Biology, 167(5), pp.69
– Sea Search: https://www.seasearchsa.com/
– Dyer Island Conservation Trust: http://www.dict.org.za/
– Murdoch University: https://www.murdoch.edu.au/
– Stellenbosch University: http://www0.sun.ac.za/
– Marine Dynamics Shark Tours: https://sharkwatchsa.com/
– Save Our Seas Foundation: https://saveourseas.com/
– Marine Biology journal article: https://link.springer.com/article/10.1007%2Fs00227-020-03837-4 .
Will You Dive With A Great White Shark?
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Will you dive with a Great White Shark?
British artist Richard Symonds did. When the opportunity for a once-in-a-lifetime cage diving experience with conservationist Mike Rutzen in Gansbaai, South Africa presented itself, Richard jumped at the chance. Eight metres below the surface, protected by a metal cage, Richard watched as these magnificent creatures glided gracefully through the waters. He took the opportunity to capture these breathtaking moments in photographs and described the experience as “unforgettable”. It was a unique chance for Richard to get up close with one of nature’s most awe-inspiring creations – the great white shark. With Mike’s experienced team from Shark Diving Unlimited on hand, it was possible for Richard to safely witness the majestic beauty of the creatures. It’s a testament to what can be achieved when conservation and tourism come together, allowing more people to appreciate these magnificent animals in their natural habitats. An experience that any nature lover would cherish forever!