We call this playing the drums.

With this app, it's we're playing the drums right now.

No, Cynthia and I have not started a rock band.

Although, you know, this whole podcast thing doesn't work out.

At least we have a fallback plan.

The songs in this case are the sound of the chains of a fishing trowel net hitting the side of a boat.

This episode, we're tackling something that sounds like a book you read to little kids.

One fish, two fish, red fish, blue fish, you mean?

Exactly. Or in this case, counting fish.

You're listening to Gastropod, the podcast that looks at food through the lens of science and history.

I'm Cynthia Graber.

And I'm Nicola Twilly.

And this week, we are taking on one of the universe's great mysteries.

How many fish are in the sea?

And are there really plenty more?

Because it's rather a big deal.

And if you stop to think about it, it seems almost impossible to figure out how many fish there are, but scientists do give us numbers.

Where do those numbers come from?

And how accurate are they?

The fate of fish and fishermen.

They both rely on us getting these numbers right.

And as it turns out, counting fish is undergoing something of a revolution right now, with drones and robotics of Marines and all kinds of new high-tech gear.

...