A Ptale of Pteriffic Pteropods
I hope you’re sitting comfortably, so I can tell you a tale,
About my favourite species of planktonic snail.
They’re called pteropods, spelt with a silent p.
And they live at high and low latitudes, out in the sea.
Why do I study these snails? You’ll want an explanation!
Well they are early indicators, of ocean acidification.
This occurs when CO2 dissolves into the ocean,
Changing its chemistry, it’s quite a commotion.
Carbon dioxide and water make H2CO3,
Known as carbonic acid, to you and me.
This acid splits into ions of bicarbonate and hydrogen,
Lowering the pH of the ocean.
The ions of carbonate decrease as well,
And these are the building blocks, of a pteropod shell.
With fewer building blocks it will take more energy,
To build a carbonate shell from the sea.
But why are they important, if they disappear will we know,
They are, after all, the size of a flake of snow.
They live in the surface ocean, but when they meet their fate,
Their shells fall to the sea floor, shuttling carbonate.
And let’s think about the food chain: what eats at pteropod?
They’re snacks for sea birds, krill, and juvenile cod.
So if pteropods decline, and you enjoy eating chips and fish,
You might find there’s a price increase, of your favourite dish.
I’ve focused my work on the shells of pteropods,
To learn about the resilience, of these little gastropods.
I look in the microscope and image every shell,
Then some lucky specimens, get CT scanned as well.
CT scans combine X-ray from many orientations,
To create three-dimensional representations.
This 3D data can be used to quantify,
Shell thickness and volume, of each sea butterfly.
We used this method, to see how pteropods faired,
If their shells start to dissolve, could they be repaired?
The samples came from the Greenland Sea,
Which experiences ocean acidification, seasonally.
There were signs of dissolution, on more than one shell,
White marks on the surface, from when pH fell.
CT scanning showed that these patches on the surface,
Were both thicker, and thinner, depending on the place.
Where shell repair had happened, we could now tell,
The repaired part was three times as thick as the original shell.
For us, this finding was absolutely brilliant,
As this repair mechanism, makes pteropods more resilient.
With that said, there is still a lot we don’t know,
About energy requirements to fix the shell from below.
Will this affect the development of the swimming snail?
Will reproduction be delayed; will the shell be more likely to fail?
Let’s take a step back, and think about the cause of this problem,
Why are the oceans, becoming less hospitable for them?
Remember ocean acidification, is caused by increased CO2
It’s at the source of this problem that we have work to do.
Carbon dioxide emissions come from burning fossil fuels,
Which we use for transport, heating, and industrial tools.
So, we need to reduce, our CO2 output,
To make sure pteropod shells, don’t go caput!
Let’s move to alternative green sources of energy,
Cycle to work, insulate homes, and harness energy from the sea.
Eat less meat and more plants, a lower carbon diet,
And if green issues come up in politics, we mustn’t keep quiet.
The impacts of high CO2 levels, are wide ranging,
Affecting animals and humans worldwide, something needs changing
Let’s work together, create a better world for you and me,
But also for our favourite plankton pals, out in the sea.
A poem about my favourite type of planktonic snail, pteropods!
This poem talks about pteropods, how they're affected by climate change, some research findings, and what you can do to help!
Presented at AGU2020 in session ED055. For more details about the original research, please see the published papers:
- Methods for CT scanning pteropods
- Pteropod shell repair