Why Can't We Be Friends?

(4 of 5)
--TIGER SHARK Jesse Spencer, now 18, from the Big Island of Hawaii, was surfing near Kona in October 1999 when a 10-ft. tiger shark came halfway out of the water and pushed him off his board. The shark's nose struck Spencer's head, then its jaws locked onto his arm. "I could almost see the whole shark. My elbow was down his throat." The shark ripped muscles, tendons and blood vessels, then chomped down on the surfboard before finally disappearing. Spencer made it to shore, and today his arm is recovering, although he still cannot grip with his hand. His mistake? Surfing at sundown.

The tiger shark generally hunts at night. It is an indiscriminate eater, "willing to try anything for food," says Rocky Strong, a shark biologist associated with the Jean-Michel Cousteau Institute. Not just fish, turtles and sea mammals but also dogs, boots, beer bottles and unopened cans of beans. Its teeth are serrated, with a notch to catch and cut through ligament or shell tissue.

Tiger attacks on humans have been on the increase in Hawaii, and one reason, says John Naughton of Hawaii's Habitat Conservation Program, may be the increase in seagoing green turtles since they were protected in the 1970s. "Turtles come close to the shore, and the tigers follow them to prey on them. That puts them in the same area as swimmers and surfers." Tigers are slower swimmers than great whites and not as good at surprise. Human victims often see the shark before it closes in to attack. But tigers are persistent. "If you are bitten by a tiger, you have a good chance of being chewed up. They come back," says John McCosker, a scientist at the California Academy of Sciences.

After a spate of attacks in Hawaii in the early '90s, islanders headed out to kill the rogue tigers. But scientists have since learned that tigers are not territorial, and so chances of catching the culprit at an attack site are minimal. Dr. Kim Holland of the Hawaii Institute of Marine Biology at the University of Hawaii has been monitoring tiger movements with the CHAT (Communicating History Acoustic Transponder) tag. Implanted in belly walls to log the shark's position and depth, the CHAT tags upload their information to underwater receivers, usually placed in shallow bays, which are retrieved every three weeks. "We know they don't stake out declared territories. They are inter-island travelers," says Holland.

--BULL SHARK When Dawn Schauman was attacked by an 8-to-10-ft. bull shark in October 1993, she said, "it felt like a truck had slammed into me, then I felt a compacting squeeze and an acute burning in my left hand and my left leg." The shark spun her around, leaving her disoriented as she hemorrhaged blood into the water. The shark left, and willpower alone got Schauman--6 1/2 months pregnant--back to shore. Her baby was later born prematurely but safely. For months Schauman woke at 3 a.m. replaying the attack in her head.