Divers often resort to metal armour, harpoons or simply staying in a cage to protect themselves from sharks, but researchers have shown that magnets could be the way to ensure ‘safety beneath the waves.’
He first discovered this in 2005 when he accidentally dropped one into his shark research tanks in Oak Ridge, New Jersey.
The resident lemon and nurse sharks inside raced away from the magnets as fast as they could.
He demonstrates just how effective magnets are at repelling sharks in a video (below) in the Bahamas.
The footage shows one of his collegues coaxing a small lemon shark into a sleep-like state by holding it gently upside down.
Mr Stroud then holds a piece of card next to the shark to make sure it can’t see what’s coming and moves a magnet right next to its head.
The shark instantly bends away from it, unable to stand being close by. Mr Stroud believes the process that’s taking place, is the magnet interfering with the shark’s electrical sensors, called the ampullae of Lorenzini.
These are used by the creatures to find their way around, because they tune in to the electric fields of ocean currents.
Mr Stroud said, ‘It’s probably something like a bright flashlight across your eyes. It’s just temporarily blinding, and you’re startled. And it’s not pleasant.’
To this end repelsharks.com already sells magnetic fish hooks developed by SharkDefense, while Stroud suggests that rows of underground magnets would be a far better way of keeping swimmers safe, while at the same time ensuring the sharks come to no harm.
However, not everyone is convinced of the effectiveness of magnets at keeping sharks at bay. Popular TV show Mythbusters conducted a series of experiments to test the theory and found that magnets only work with some species of shark, and not in every circumstance. It showed that lemon sharks ignored the magnets when there was food attached to them.
Attribution: The World