[dramatic music]
NARRATOR: So what is behind this deadly spate of attacks?
According to local news reporter Jerry Sinon,
it's a question on everyone's mind.
There was a lot of rumors in regards to the attacks.
Why did it happen?
And in two weeks time it happened twice.
NARRATOR: One such rumor concerns the identity
of the killer shark.
The ferocity of the attack and the severity of the injuries
incurred seem to point toward the ocean's
most fearsome predator.
People were saying that it was a white shark.
[electronic music]
NARRATOR: Great whites are the largest
predatory fish on the planet.
Growing up to 20 feet in length, they are powerful hunters,
able to propel their bodies completely out of the water
when attacking prey from below.
And they are responsible for more fatal attacks
on humans than any other shark.
So is this the species behind the spike?
Determining that type of shark may help locals prevent
attacks from happening again.
Shark expert Dr. Enrico Gennari studies great whites
off the coast of South Africa.
He believes the answer to whether a white shark could be
responsible for the Seychelles attacks may come down to where
these predators go and why.
White sharks travel a lot.
All their life is about moving.
NARRATOR: Gennari has spent the past 13
years tagging these predators to track their movements.
Using a long pole, he attaches a small non-invasive device
to their fins.
[suspenseful music]
ENRICO GENNARI: OK, shark coming.
3, 2, 1.
[dramatic music]
It's on.
Yes!
Now we track it.
NARRATOR: Through such tagging studies, experts like Gennari
have discovered that white sharks are highly migratory.
In fact, some great whites will swim up
to 1,000 miles each month, or more than 40 miles per day,
to reach a destination.
ENRICO GENNARI: Often, white sharks
are attracted to a specific place because of food.
NARRATOR: But in their quest for prey,
white sharks don't just go anywhere.
It really depends on the temperature in the water.
NARRATOR: Unlike most other sharks,
great whites are warm-blooded.
That means they always maintain their body temperature above
that of the surrounding sea.
So they thrive in a particular climate.
White sharks usually like water temperature quite cold.
NARRATOR: This is the key to the investigation
in the Seychelles, because great whites are typically
found within temperature ranges of 54 to 75 degrees Fahrenheit.
But the water off of the islands routinely reaches into the 80s.
White shark definitely don't like tropical water
like in Seychelles.
So that shark in the Seychelles most likely
was not a great white shark.
NARRATOR: The culprit's identity and the reason
it attacked remains unknown.
For locals and tourists in the Seychelles,
it's a disconcerting premise.
It's still a mystery and people
still wanted to know why.
[suspenseful music]