How rare earth metals and magnets repel sharks
An American chemist says he has found several substances that can repel sharks.
Sharks possess electrical sensors, called the ampullae of Lorenzini, that look like tiny freckles on their snouts.
Biologists believe sharks use these sensors to detect the heartbeats of their prey and to navigate using the Earth's magnetic field.
In 2004, Eric Stroud found that magnets repel sharks, possibly by overwhelming their electrical sensors, and now he says his team has found that some rare earth metals appear to have the same effect.
Eric Stroud and a colleague demonstrated the effect of magnetised rare earth metal on a lemon shark they had just caught off the Bahamas.
Video courtesy of PRI's The World.