Tagged South Africa

Video: Baited great white shark bumps into cage

A video shot off Gansbaii, South Africa of a white shark bumping a cage, after charging a hang bait, has been making the rounds in the (largely tabloid) media today. Some of the more creative news outlets have referred to the shark in the video as “trying to bite through steel bars of diving cage” and “charging the cameraman.” However, the behavior seen in the video does not appear to document anything beyond the shark going after a bait in close proximity to the cage and then bumping the cage after the bait was pulled away. The white shark does get briefly “tangled” with the bars of the cage, but eventually swims off without further incident.

White sharks do not have the ability to swim backwards, so when they are charging a bait momentum will often cause them to continue in the same direction, even if the bait is pulled away from them. Additionally, when attempting to bite prey, white sharks will often roll their eyes backward as a protective measure, rendering them temporarily blind, which can also contribute to collisions if bait is close to cage. The behavior exhibited in this video seems consistent with a shark merely going for a hang bait and subsequently bumping into the cage as a result.

Woman celebrates 100th birthday with great white shark dive

As part of Georgina Harwood’s 100th birthday celebration, she went on a great white shark dive off Gansbai, South Africa, yesterday. In addition to the shark dive, Harwood also celebrated turning 100 with a skydive two days earlier. Harwood, a great-grandmother, began skydiving when she was 92, but this was her first shark dive.

Her recent skydive was done, in part, to help raise money to buy life-jackets for volunteers at South Africa’s National Sea Rescue Institute, according to a HuffPost UK article.

If you’d like to donate to Harwood’s life-jacket fundraiser, you can do so here.

Stealthy seals sneak past white sharks using subsurface structures

The following was shared with us by shark researcher Michelle Jewell…


Stealthy seals use subsurface structures to sneak by white sharks

Written by Michelle Jewell (@ExpatScientist)

Predators are highly influential in ecosystems because of the many top-down effects they can have. The most obvious and direct way predators influence an ecosystem is by eating and reducing the number of prey animals in the system, but another equally important way is the indirect influence they have on the behaviour of prey animals.

If you have avoided parking on a risky-looking street, taken a different route between classes to avoid a bully, or abandoned a forest hike because of snapping twigs in the distance, you have been indirectly affected by perceived ‘predators’. In the wild, prey animals will also change their behaviour when they perceive that predators are around, and these altered behaviours often influence other species, ultimately shaping the ecosystem.

My research has focused on these same principles of predator/prey interactions in the ocean, and a great place to study oceanic predators and their prey are Cape fur seal colonies in South Africa. Every summer (November), Cape fur seals give birth to thousands of pups, and by winter (April – September) these ‘young-of-the-year’ seals begin to venture off their islands to swim offshore to the fishing grounds with the adults. These young-of-the-years are typically slow, plump from months of a mostly fat milk diet, and – most importantly – naïve. White sharks take advantage of this naivety and aggregate around seal colonies every winter. Young-of-the-year pups are forced to learn how to avoid sharks quickly or suffer some rather permanent consequences. This means that during a full year, every seal colony goes through a period of high white shark presence (winter) and very low to no white shark presence (summer). Therefore, we are able to study how seals act ‘normally’ during the summer when there are no/very few sharks and how they change their behaviour in the winter to avoid white sharks.

Also, there are many different kinds of seal colony islands along the coast, which lets us ask more questions about how seals use their environment to avoid sharks. I conducted my study at the Dyer Island/Geyser Rock system, which is home to ‘Shark Alley’ as well as many shallow reefs, kelp forests, and shipwrecks. About 100km to the east is another seal colony called Seal Island, which is a world-famous spot to see white sharks predate on seals, but this island system lacks the abundant nearby structures/reefs/kelp forests that are present at Geyser Rock. By looking at these two different kinds of islands, we can also examine how structures – or ‘refugia’ – may alter how seals avoid white sharks at Geyser Rock from how seals avoid white sharks at Seal Island.


Research Conducted by Marine Dynamics a Shark Cage Diving Operator in Gansbaai South Africa

Do all of these structures and anti-predatory tactics of Cape fur seals change white shark movements around Geyser Rock? Most definitely! Check out that study and infographic!

For more information, check out the detailed scientific publication in Behavioral Ecology & Sociobiology.


Big thanks to Michelle for sharing her research and awesome infographic! For more from Michelle check out her Michelle’s Expat Scientist blog.

Nat Geo Channel’s ‘Die Trying’ to feature white shark tagging

“Great White Ambush,” this week’s episode of National Geographic Channel’s “Die Trying,” will follow a team of shark experts, along with wildlife filmmaker Andy Casagrande to Shark Alley off the coast of Gansbaai, South Africa. The team’s goal is to capture a white shark (Carcharodon carcharias) in hopes of mounting data loggers and camera tags on the back of the shark, in order to scientifically document the complete profile of a breaching great white for the first time ever.

The episode airs this Wednesday, July 30, at 10PM ET on the National Geographic Channel.

Spearfisherman has close encounter with great white shark

WARNING: Video contains language that may be offensive to some.

YouTube user Eugene van Wyngaardt had a close encounter with a white shark (Carcharodon carcharias) while spearfishing off the South African coast. Van Wyngaart described the shark as a 5m female. The white shark came in for a close enough look that van Wyngaart gave her a prod with his speargun. The shark circled the boat 3 times after van Wyngaardt got out of the water, according to the video description.