Great white sharks have migrated from Cape Town to the Eastern Cape coast, with high numbers reported in Chintsa Bay, researchers have found.
Fifteen great whites were found in Chintsa Bay between January 17 and 19 by a five-member team of Western Cape scientists, filmmakers and divers.
Nine were tagged in their dorsal fins. Fourteen were young or sub-adults of more than 2m long, which could live for 70 to 80 years and grow to more than 5m-long.
One was a juvenile.
News of the latest taggings evoked keen interest from close to 200 anglers, paddlers, divers, swimmers, skippers and crews who crammed into the Kwelera Ski Boat clubhouse last week for the research presentation and discussion.
The scientists said the tags — apricot-sized computers costing R80,000 each — were programmed to work free from the fins and float to the surface after 180 days, which will be in July.
There they should link with a satellite and download their data, called “gold” by one researcher.
They and the public would have had their first local hard truths about this significant migration and eco-shift.
Their findings are likely to spark international interest amid a global fascination with the behaviour of the famous top-tier marine predator.
The team appealed to the public to report any shark sightings or encounters to toby@sharkspotters.org.za.
For a number of years, local ocean users along the East Coast have reported seeing more and more great white sharks, especially in Chintsa Bay.
On April 12 2021, at about 11am, Chintsa bodyboarder Robert Frauenstein, 38, disappeared. He is believed to have been taken by a great white due to shark bite marks on his board, which was found the next day.
The deep, clear punctures were identified as belonging to a great white by Kevin Cole, principal natural scientist at the East London Museum.
There has been no further sign of Frauenstein.
However, surfskis have been bitten, some in two, boats have been buzzed and bumped, a free diver was rubbed into a crevice by a huge female and another thrown into the air when the shark breached.
In the latest encounter on January 5, a fun kayak paddle off Glen Eden turned into a scary encounter with a large great white.
Ski-boat anglers and aviators have provided the team with a lot of information about great whites spotted in the area.
Most of the talking at the meeting was done by research manager of Shark Spotters SA, Dr Toby Rogers, and Dr Alison Towner, a dedicated great white shark researcher doing her post-doctoral research at Nelson Mandela University.
They said the pivotal cause of the great whites migrating to the Eastern Cape was their predation by two highly intelligent and unique male orcas, given the names Port and Starboard, which had taught themselves how to catch and fillet the nutrient-rich livers of sharks.
In one day the orcas killed 23 broadnose sevengill sharks in Gansbaai — just for their livers. The elusive orcas have evaded tagging so far.
The researchers said a blend of research had shown that great whites were seldom found in the Western Cape, while numbers remained static in KwaZulu-Natal, which has a high kill rate from its shark nets.
But there was a growing body of local information which supported the view that great whites were living in abundance in the Eastern Cape.
They said the sharks and the reefs in Chintsa Bay were in excellent health.
Saying that more formal research was needed, the scientists described great whites as curious, even playful, and predictable.
But they were predators, and even an exploratory bite on a human, who were not part of their regular diet, caused extreme trauma.
The research from the tags could give the first comprehensive picture on how the sharks were behaving, if they were lingering in the bay or were also present in big numbers on the Wild Coast where limited research has been done.
Methods to mitigate against human encounters with sharks included use of drones, deploying shark spotters on the shore and having bite kits available, as wll as knowing which conditions suited the whites and assessing the risk.
Rogers said: “A more formalised risk assessment of your coastline is required to find the most appropriate tools to mitigate human-shark conflict.”
Towner explained how tagging the sharks was extremely difficult. They have travelled thousands of kilometres in quick time and do not hang out in groups.
Buffalo City spokesperson Bongani Fuzile said while the metro had, for safety reasons, improved its communication with the public over shark sightings, the numbers seen off BCM beaches had remained consistently low.
Eastern Cape Parks & Tourism Agency CEO Vuyani Dayimani said: “We support a responsible, science-led approach that encourages people to follow guidance issued by relevant coastal safety authorities and local municipalities, and to avoid speculation that may cause unnecessary panic. Shark presence along our coastline forms part of a healthy marine ecosystem.
“Changes in ocean conditions such as water temperature, currents and the movement of bait fish can influence where marine predators are observed, but confirmed interpretation should be left to marine scientists and the appropriate monitoring bodies.
“From a tourism and conservation perspective, the Eastern Cape’s ocean and wildlife offering remains a key part of our destination appeal, including the province’s big seven positioning, which recognises the great white shark as part of our natural heritage.
“The priority is to promote safe, informed enjoyment of our coast while reinforcing the importance of protecting marine biodiversity as part of sustainable tourism.” — Daily Dispatch
