High-resolution photographs of the teeth, matched with known shark data, determined that eight species were hunted for the weapons. The spot-tail and dusky sharks were part of that group, but these species have never before been reported from Gilbert Island reef waters.
The discovery suggests that these two sharks were hunted by the islanders until they were locally extinct.
Historical records explain how these sharks and the others were hunted. The process involved a strict set of procedures. First, two men would go out in a narrow outrigger canoe measuring 10 to 15 feet long.
"One would use a series of coconut shells as a rattle to lure the shark close," Drew explained. "When the shark would come to take an investigatory bite, he would thrust a stick down the shark's mouth, forcing the jaws open. At the same time, the other man would slide a rope around the tail of the shark."
At that point, the immobilized shark would be fastened to the side of the canoe, hauled ashore and then killed. Its meat was consumed, with the sharkskin later used to craft household goods. The skin and the teeth were used to construct weapons.