Frequently Asked Questions on Sharks

What do Sharks eat?

Most sharks feed on bony fish of some or other description, mostly related to where they occur. Large, highly predatory sharks such as the great white, bull, tiger oceanic white tip and a few others can also eat mammalian prey such as seals and sea lions as well as scavenging whale carcasses and other large prey items. The shark that probably has the greatest range of different meals is the tiger shark which will eat pretty much anything from fish, turtles and fledgling albatross to car number plates, boots, cans and a range of other strange items.

How many species of sharks are there?

In South Africa we have over 100 species of shark, pretty lucky I would say. Around the world there are nearly 400 different species from the massive whale shark to the diminutive pygmy shark with a variety of oddities such as the bizarre looking goblin shark and recently discovered megamouth shark. If you live on the coast do a little research into what sharks are near you and I bet you will find you have some pretty cool sharks as marine neighbours.

How do you attract sharks?

Well most people think throwing blood in the water works but this is actually fairly ineffective as it quickly disperses. Low frequency sounds travel for huge distances and in many cases resemble struggling fish sounds and therefore act as a magnet to predatory sharks. Dying or struggling fish who are injured also attract sharks by virtue of odor from wounds, vibrations from their struggles and sound from irregular thrashing, hence fishermen often loosing their catch to sharks.

That said, sometimes sharks just are plain uninterested in anything we might do to attract them and pretty much just go about there days activity without paying us any attention.

Where do Sharks live?

Pretty much all over the world, except the very cold Antarctic, sharks have successfully occupied some or other niche. Sharks live in the warm and cold oceans of the world and inhabit water right from the surface to over 1000 m deep adapting themselves to a life in the dark.

Great white sharks occur in temperate waters around the world in water typically from 12-21º C but can be found in water as cold as 4º C and as warm as 28º C. Many sharks have an ability to regulate their body temperature above or below the surrounding water.

Why do Sharks attach humans?

Firstly shark attacks are very rare .There are also a variety of reasons sharks may attack people. Some in the know speculate in the case of great white shark attacks that it is mistaken identity of us looking like a seal when silhouetted against the surface. In many cases of shark attack the shark has been provoked by being hooked, injured or cornered and it is just a natural defense action on the shark’s part.

More complex ideas suggest we may even be unknowingly engaging sharks socially by challenging them with certain body postures as they would do each other and as such we initiate combat/interaction or defensive aggression. Who really knows?

What we do know is that sharks do not hunt people naturally because if they did thousands of unagile bathers would be gobbled daily. Humans must also realise that we are invading their territory and occasionally no matter how slim the chances are we do occasionally fall prey to sharks. Put in perspective however over 100 million sharks are annually killed by humans and less than 25 humans are killed by sharks.

A ratio of 1 human for every 4 million sharks we kill. Sadly sharks have far more to fear from us supposedly intelligent humans than we need to fear them.

How do sharks maintain neutral buoyancy?

Unlike fish which have air bladders mid and surface water sharks have very large livers filled with very buoyant oil. As a result sharks can also regulate their position in the water column like fish but just use a different method.