NARRATOR: In Bimini, Bahamas, a team of experts

are hoping to entice a couple sharks for an experiment

and get more than they bargained for.

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They're testing if sharks can detect magnetic fields.

The answer could unlock a major mystery about how sharks find

far-flung, food-rich volcanic islands

and whether the island's naturally magnetic lava

rock is involved.

For this open water experiment, they

arranged three powerful magnets to the right

and three non-magnetic controls to the left.

A big hammerhead glides over the aluminum control

without a glance and heads for the magnets.

Hammerheads ignore the aluminum, clustering around the magnets.

The nurse sharks have a greater response.

Nurse sharks are drawn to the magnets.

The sharks are agitated, possibly by the magnets.

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That was fantastic.

That was great.

So many hammerheads down there, all over the place.

A bunch of nurse sharks.

The nurse sharks were playing at the magnets.

Really neat dive all around.

Yeah so that dive was crazy.

We had nine hammerheads there.

We got what seemed like countless nurse sharks.

What we saw was that both the nurse

sharks and the hammerheads did respond to the magnets.

So what we can take away from that

is that those weak magnetic fields that are locked

in volcanic rock are something that the sharks

could detect and may be able to use in navigation.