Since its portrayal in Jaws, and later in Finding Nemo, the great white shark has captured the imagination of people across the globe. In South Africa, our relationship with the great white shark is a little closer than most, with stories of amazing shark sightings, regularly human-shark interactions and, more recently, the great white's mysterious disappearance from False Bay gripping the media and feeding urban legends.
Despite the fame, or infamy, of the great white shark, most people have little factual knowledge of the lives of these incredible animals. Even amongst the scientific community, which has not been tainted by Jaws, there are still a host of unanswered questions. We were fortunate enough to welcome some of the world's leading shark experts to the Two Oceans Aquarium on Shark Night - these are 10 facts that fascinated us the most:
(Cover image by Sharkcrew CC BY-SA 4.0)
1. Great whites are very curious
Great white sharks are very curious and will often poke their heads out of the water or follow boats just to see what's happening, a behaviour called spyhopping. They are one of the few marine fish that pay attention to what happens outside of the water. In nature, this is an important behaviour for a great white to master, as it allows it to spot its prey, like seals, that spend time on land and its predators, like orcas, which need to come to the surface to breathe.
Because of this natural curiosity, great whites are known to approach boats to look at people - this is not an aggressive behaviour, it's just the shark's way of seeing what you are.
2. South Africa uses drones to spot sharks
South Africa's Shark Spotters are pioneers in the field of human-shark interaction, and countless shark and human lives have been saved by their teams of vigilant lookouts that are stationed on the South African coast. Recently, Shark Spotters have added a new tool to their trade - employing drones to get a closer look at what lies below the water at Cape Town's popular beaches.
3. This viral photo is real
Well, no, not this one. Not this Chinese shopping mall flood, but the sharks shown above are real.
What about this one? No, a shark didn't swim down a US street after Hurrican Joaquin.
The sharks show above are actually a South African great white that was spotted by the White Shark Trust while conducting research on the Western Cape Coast. Displaying the characteristic "great white curiosity" that we mentioned earlier, this shark spent the day following around Michael Scholl and his fellow researchers. Today, this incredible animal has been immortalised by memes and incredible real photos alike.
4. Shark fins are like fingerprints
Shark fins are unique, and South African scientists are using them to identify individual sharks without using tags. This identification strategy was developed over the past 22 years by shark scientists from the Save Our Seas Foundation and others. Great white sharks get small injuries on their dorsal fins that form notches of varying sizes on edges of their fins. Although these bumps and grooves heal and change over time, the process is slow enough that individual sharks can be monitored simply from photos of their fins. Recent advances are allowing this process to be automated - it's an exciting time to be a shark scientist!
5. Great whites are fast long-distance swimmers
By using satellite tags and the finprinting technique mentioned above, scientists from the White Shark Trust were able to track a young female great white shark from Gansbaai to Australia and back, a journey of over 20 000km, in under nine months - the fastest transoceanic migration of any marine animal (including famous migrators like leatherback turtles and tuna).
6. Great whites are not the top of the food chain
Orcas are being blamed for sharks leaving False Bay, and although they are not the sole cause of the sharks' absence, they are a player. Type A orcas, like Port and Starboard on the South African coast, are known to feed on sharks. In False Bay, the orcas feed on sevengill sharks, great whites and bronze whalers. Although there is evidence to suggest that the orcas work in pairs to hunt sharks and remove their livers, eyewitnesses have seen solo orcas predate on sharks too.
Moral of the story - the adorable "sea panda" is actually the most dangerous predator in the ocean.
7. We have never seen a great white mating or giving birth
Despite our best efforts, very little is known about the reproductive lives of great whites. We know from autopsies that females give birth to two to ten live pups after about a year of gestation. We also know, from the scars we see on adult sharks, that they bite each other as part of the mating ritual (a behaviour in sharks). And, we know that baby great whites are kept in nurseries in places where food is abundant - although we don't really know where these all are.
Despite the above, we've never caught the act of mating or pup birth on film - in fact, there are no credible eye witness accounts at all. It is assumed that great whites migrate to safe areas to mate, but we don't yet know where.
8. South Africa was the first country to protect great whites
In 1991, the fishing and exploitation of great white sharks became illegal in South Africa, the first country to protect great white sharks. In fact, it wasn't until 2005 that shark conservation would start being taken seriously globally, with various shark species gradually being added to CITES, the regulations the govern the trade restrictions of protected animals, since then.
In South Africa it is illegal to intentionally catch or kill a great white shark. Great whites that are accidentally killed, need to be kept whole for inspection by a fisheries officer, and no part of a great white shark may be sold.
9. South Africa has a system of flags for shark warnings
Many Western Cape beaches which are prone to visits from sharks are monitored by Shark Spotters, trained lookouts who scan the waters for signs of sharks. When these lookouts want to communicate with the public they use a flag. If you've visited a local beach you may have seen one of these flags flying, but do you know what they mean?
Here's what the different colours mean:
- GREEN: Spotting conditions are good and no sharks have been spotted.
- BLACK: No sharks have been spotted, but visibility is poor.
- RED: Be on alert, a shark was spotted nearby or recently.
- WHITE: A shark has been spotted at the beach, leave the water. (A siren will sound too)
Shark Spotters maintain a regular presence at Muizenberg, St James, Kalk Bay, Fish Hoek and Caves, as well as a number of seasonal beaches. Have a look here to see when and where the Shark Spotters are on the lookout.
10. You can learn about sharks for free
Members of the public can visit the Save Our Seas Foundation Shark Education Centre in Kalk Bay, Cape Town for free. This is an experience not to be missed and includes many state-of-the-art exhibits, like simulations of what it feels like to hunt using a shark's senses.
Be sure to get in touch with the Shark Education Centre before visiting to be sure of their operating hours.
We hope you enjoyed these 10 "great" great white shark facts as much as we did when learning about them! If you'd like to know more about South Africa's incredible sharks - be sure to read this blog next.