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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.