White Shark Breaching
Among the most
spectacular of White Shark behaviors observed at Seal Island is the breach, in
which a several hundred- to several thousand-kilogram animal explodes from the
sea in an awesome display of power and acrobatic prowess.
Not only are these events astonishing to watch, but they also reveal clues about how White Sharks normally attack their prey. Unfortunately, one can virtually never determine where a White Shark is going to breach before it actually does, making this phenomenon difficult to study or capture on film.
To facilitate observation, photography, and filming of White Shark breaches in False Bay, Chris Fallows and Rob Lawrence of African Shark Eco-Charters developed a technique of slowly towing a seal-shaped decoy behind a boat. Sometimes, a White Shark will hit the decoy within very few minutes of beginning a tow. At other times, White Sharks seem completely uninterested in the decoy.
Interestingly, shape discrimination in White Sharks seems to be partially dependent upon its state or motion or rest. A seal-shaped decoy that is floating more-or-less stationary on the surface must be shaped reasonably accurately to elicit investigatory behavior; in contrast, a towed decoy need not be shaped all that accurately to elicit a spectacular response.
Below are a few stills captured from video shot by Rick Allen of Nautilus Productions and a short video-clip from a rare and particularly spectacular double breach. On a separate page, there are close ups of the damage done to the decoy (carved from a body surfing 'boogie board'), including a preliminary analysis of the size and technique of the attacking White Shark.
 |
WHAM-O!! To give you a sense of scale here, the decoy measures about 1.2 metres long by 0.5 metres across |
|
Crunch!! Another good hit! Note the 'keel' on the decoy, projecting upward just in front of the shark's mouth. This keel helps stabilize the decoy and makes it 'skip' and 'bounce' enticingly across the surface as it is towed. |
 |
 |
Head stand! Possibly because much of the animal's mass is concentrated at its anterior end — the teeth, heavily calcified jaws, hyoid and gill arches, and supporting musculature — breaching White Sharks often 'cartwheel' after they explode from the water. |
|
Oops!! You just know that when this acrobatic beauty boasts about this to his sharky friends, the size of The One That Got Away will be grossly exaggerated! |
 |
Click here to see QuickTime movie showing a spectacular double breach by a White Shark in False Bay, South Africa. The footage was shot by Rick Allen of Nautilus Productions. The first breach goes completely out-of-frame because — quite frankly — Rick didn't expect the White Shark to be able to leap so high. But, by the second leap, Rick's long-time filming experience kicked in and he 'nailed it'!
If you don't have QuickTime, you can download the viewer.
