MOANA

Kia ora, what are you up to in the gallery?

URSULA

Kia ora. I'm Ursula Cochran.  I'm a scientist from Wellington, and today I'm looking at this amazing circle of shapes. Each of those unique shapes is a diatom.

MOANA

Diatoms … what can you tell me about them?

URSULA
Diatoms are single-celled algae. And the reason we can see them today is that they build their shells out of silica. So they last a very long time in the fossil record, and each of those shapes is a different species.  There's thousands and thousands of species that have been identified on Earth. But these ones here are from Oamaru, and they are a few tens of millions of years old.

It's hard to believe that a single living cell would go to so much effort to build such regular and perfect shells.

MOANA

They do belong in an art gallery don't they.

URSULA

I've always seen the artistic qualities in them, and I guess was drawn to studying them because they're so beautiful.

But at the same time, to me, their most powerful asset is the fact that we can use them to talk about past environments and past times on Earth when the climate was different or the oceans were different.

MOANA

So you’ve studied diatoms as a scientist, where do you find them?

URSULA

So if we move to the left of the arranged circular slide, we come to this image on the end of the series of six here, where you can see diatoms just strewn across the picture.

To me, this slide is exciting because it represents an assemblage of species that were actually living together. So it's more how the diatoms are found naturally in the environment.

This is the kind of microscope slide that I would have been working with as a geologist.

MOANA  

So how big are these diatoms, in real life?

URSULA

Shall we go into the middle of the room to look at the actual microscope slides?

And this really gives you a good sense of how big diatoms are. Because, if you can see, can you see any little grains under these slides? It's very hard to see any little flecks at all.

And yet, under all those circles are a whole arrangement of diatoms.

So, they all have Latin names to identify them. And it's kind of like an exotic poem. You can see navicula, pinnularia, nitzschia, surirella, epithemia, eunotia. Yeah.

MOANA

Stunning. But what are these plain looking white rocks here?

URSULA

Super boring. I mean, you would totally walk past these. They just look like grey mudstone or something, right? These are actually diatomite. Diatomite is the type of rock that forms from almost pure diatoms.

What I love is you take a little crumb of this and put it under the microscope and you end up with a universe of beautiful algae. Yeah, I know that that would look incredible under a microscope.

MOANA

Tēnā koe Ursula. That was so enlightening.

Now we’re done in this gallery, and we’re heading next to an exhibition called ‘This Natural World’. Go back through ‘Arranging Nature’, turn left into the last gallery and find the video work right at the back.