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Along with California, Australia, and Isla Guadalupe, the waters off the coast of South Africa are home to one of the largest populations of great white sharks in the world. Unlike the other great white shark locations, the sharks surrounding Seal Island in False Bay off the coast of South Africa display a unique hunting behavior. Here the sharks will breach, powerfully launching themselves out of the water, to attack the seals that live on and swim around the island. Specific to this area, this awe-inspiring behavior has been studied and analyzed more thoroughly in recent years.
Seal Island, named for the huge number of Cape Fur Seals living on it, is located a little over 3 miles off the coast of False Bay near Cape Town. Beyond the immediate shallows, the island is surrounded by steep drop offs. The circle of water above the drop offs around the island is often referred to as "The Ring of Death," as it is in these waters that dozens of large great white sharks prowl, breach, and kill their favorite prey. The deep drop offs allow the shark to both maintain the element of surprise against the seals swimming near the surface, as well as giving them the space needed to build up the speed for water-clearing strike on the pinnipeds. These tooth-laden torpedoes, often weighing close to 1.5 tons, breach with incredible speed and force, displaying a level of agility and athleticism that very few people had previously considered them capable of. They can emerge vertically from the depths at speeds of 25 miles an hour or more when they hit the surface, and can leap as much as 10-15 feet completely out of the water.
South African photographer and shark researcher Chris Fallows has been studying these sharks and their behavior for many years. He has used many different research and filming methods to obtain information and stunning photographs/videos of these incredible animals. He has dragged seal decoys behind boats, sometimes with underwater cameras attached or towed several feed in front of them. Since the breaching attacks by the sharks usually last less than a minute, they are too fast for the human eye/brain to see and process, much less analyze. Using film/cameras shooting at 1000 frames per second, Fallows and other researchers can make a 1 second breach last almost a minute on slow motion replay, analyzing the smallest details of the super predator's attack.
Each year, between 600-800 seals are killed by the sharks. Although this might seem like a lot, it is only about 1% of the total seal population. In fact, of all the attacks or attempted attacks on the seals by the great whites here, almost 50% survive. Based largely off of the analyzed footage, researchers believe that this is due to a combination of factors. Sometimes, the shark gets only a glancing bite of the seal, or misses it completely. Either the shark slightly miscalculates when it charges upward from below, or the seal senses the quickly approaching predator, and at the last minute maneuvers out of the way as the great white rockets past them into the air. As seen in some of the analyzed slowed photographs and videos, the motion of something as massive as a great white shark moving at great through the water creates a pressure wave in front of it. Some researchers believe that the seals can sometimes feel the pressure wave before the attack and they then attempt to maneuver/escape in time. Often the seals that are attacked are young, not experienced enough to know to stay close to the other seals or to possibly pay heed and react to the split second warning of a shark's approaching pressure wave. Also, should the great white miss or glance off the seal, and older and more experienced seal will strategically maneuver/dance close up around and behind the shark until it sees an easy way back to the shallows. A young seal often heads straight back for the island, giving the shark a chance to follow it and attack again quickly.
Much more agile and maneuverable than the white shark, a seal that is forewarned or initially spared by a miss is unlikely to become a meal. However, when the massive great white shark is able to maintain the element of surprise and accurately hit its prey with enough speed/force to send both of them clear out of the water...it's usually "game over" for the seal.
Join the San Diego-based Islander Charters http://www.islander-charters.com/ this fall for a great white shark cage diving adventure in the beautiful waters of at Isla Guadalupe, Mexico. http://www.islander-charters.com/shark-diving/shark-diving-home.shtml
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