they visit an expert who ID sharks by their fins.

So we were hoping to see if you could look

through some of your databases.

NARRATOR: Shark scientist Nicolas

Buray keeps a photo archive of Tahitian tiger sharks.

That's cool.

NARRATOR: And it's been growing.

MAN: How many sharks do you have in your database?

So in our database, we have around 55

different tiger sharks.

This is new.

For 10 years, I saw maybe two only.

Right now, since three, four, five years,

we are more and more tiger sharks.

NARRATOR: Local divers send Nicolas dorsal fin shots.

He enters them into the archive and identifies the individuals.

So you're looking at the stripe patterns?

Yeah, the stripe.

When a shark's growing, they keep the same stripe.

NARRATOR: All of the newcomers are females.

Time to find out if they have a match.

This one here is Kamakai.

And the dorsal is pretty distinct.

She is mature, so there's some scarring.

NARRATOR: During mating, male sharks

bite the females, which is why female shark skin

has evolved to be super thick.

Female tigers reach sexual maturity at about 9 years.

There's no doubt Kamakai has mated.

Clearly a big female tiger shark.

But do you recognize her?

Or is she in your database?

I mean, no. No.

Not in my database.

ANDY: OK.

No.

This one is, I'm sure I don't know it.

NARRATOR: Now they compare pictures

from the database with the big females from the night dive.

This is the biggest one that we've seen there.

We were thinking possibly the same shark.

No.

For me, it's not the same.

So this one I think is not the same.

NARRATOR: Andy and Kori have just

added three new large females to Nico's growing database.

Do have the other side?

No.

NARRATOR: That makes more than 40 large sexually mature

female tiger sharks, most with dorsal fins

chewed up and scarred for mating.

Looks like just a shredded fin.

NARRATOR: Everything points to a tiger shark mating ground.

An area with males must be nearby.

So that means those other hot spots out there, other places

where these large tiger sharks are hanging out

that haven't been studied yet.

NARRATOR: If they can find it, perhaps Kamakai will

be there looking for a mate.