Shark Attack!

Sharks are mistakenly viewed as mindless killers, however their complex design responds to a number of stimuli before an attack is launched.

Sharks are primarily attracted to vibration (splashing for example) and the presence of organic chemicals (such as the blood of fish).

They have the ability to trace the smell carcass of a whale washed up on the beach from literally hundreds of kilometres away and will actively look for a meal without any other intent than to refuel.
Sharks are just basically interested in food (like all fish) and in many ways behave in a similar fashion to any other fish in the ocean.

An important characteristic that a shark also possesses is the ability to pick up the minute electrical signals generated by other organisms and therefore enables it to accurately track it's food at closer range (including in conditions where visibility is poor).

Attacks on humans appear to be in the most part a case of mistaken identity or simply being in the wrong place a the wrong time.

The majority of attacks on humans by sharks are not fatal though the injuries can range from puncture marks and a few scrapes to the loss of a limb depending on where the victim is bitten.

However larger sharks such as the Great White and Tiger can inflict severe damage and the resulting blood loss and trauma needs to be treated rapidly.

Of the hundreds of species of sharks in our oceans and estuaries only a few are considered dangerous.

The Great White is responsible for over 100 attacks on humans and is regarded as perhaps the most dangerous shark in the ocean but is also considered less aggressive than other species.

Bull sharks for example are considered even more dangerous by some experts due to their aggressive nature and have been found upriver in fresh water where people are likely to share the river resulting in more frequent encounters.

White tip oceanic sharks are extremely curious and persistent if they think there is a meal possible and are responsible for more shipwreck deaths at sea than any other species.

Tiger sharks are also considered dangerous and have been described as "the garbage cans of the sea" since they will consume just about anything and are common scavengers.