Sea urchins are as sinister as they appear. Ten years ago, in California’s vast, wavy kelp, sea urchins started to eat and breed, and eat and breed, and over seven years destroyed most of the underwater forests. Then they settled on the floor of their wasteland, forming spiny purple carpets, clicking urchin barrens along 150km of coastline. A major marine heatwave had damaged the kelp and a “sea star wasting syndrome” killed the urchins’ main predator, sunflower sea stars.
Could they be eaten by us or by otters? They could not. They had entered a zombie state and contained very little uni, the rich meat inside the urchin’s shell. And they are prepared to stay that way: dormant, alone – until they spot any kelp sprout that dares to breed out of the dead land and eat it before another urchin can. They are method actors performing The Waste Land, and we are students in an English lesson late on a hot afternoon, trying not to fall asleep as we listen to TS Eliot’s voice on a scratchy recording, a recording that sounds like it was made in a room full of urchins, faintly clicking their spines:
What are the roots that clutch, what branches grow
Out of this stony rubbish? Son of man,
You cannot say, or guess, for you know only
A heap of broken images, where the sun beats,
And the dead tree gives no shelter, the cricket no relief,
And the dry stone no sound of water.
Urchins eat by scraping and grinding their five jaws, which are arranged in a shape that Aristotle described as a “lantern” but which he should have called a “horrible beak”. Their internal skeleton is called a “test”. Encyclopedia Britannica describes sea urchins as having a “radial arrangement of organs”.
They have tubular feet (which some urchins, when they are in shallow water, use to create hats out of seaweed or shell to protect them from the sun – it is actually quite sweet, but don’t let it fool you). Between their spines they have pincers, which they use to preen themselves or pinch bits off predators. When they move, they appear to be rolling using their spines, but they are actually moving using many tiny suckers, which reach out and pull them forward.
A baby sea urchin resembles a virus. The urchin shape grows within and when it is time, it turns itself inside out – “like a sock”, a PBS documentary describes it, before casually letting you know that urchins can live for centuries and are “practically immortal”.
But even not knowing any of this, we still somehow feel when in their presence that they are worse than the spikes. That there is a reason the name “sea hedgehogs” didn’t stick. That they are powerful. That they have a darkness. (Or is it just the anus on their heads?)
I first knew sea urchins by their shells. It was years until I realised that the beautiful green and the beautiful shape of the objects on my grandmother’s mantlepiece were the same things that made my heart beat slightly faster in the sea.
• Helen Sullivan is a Guardian journalist. Her first book, a memoir called Freak of Nature, will be published in 2024
• Have an animal, insect or other subject you feel is worthy of appearing in this very serious column? Email helen.sullivan@theguardian.com