It’s a plastic plant, I exclaim! An article by Sullivan published in The Guardian titled ‘A sea urchin: they are method actors performing The Waste Land‘ claims that ‘sea urchins are as sinister as they appear’ and ‘that they have a darkness.’ Often when I see plastic plant I remark that it’s a sure sign of the impending heat-death of the universe. Oh, the irony. We try to make our world more habitable by replacing plants with a fossil-fuel derivative that contributes to more rapid ecosystem-energy collapse. Hence, I dub the aforementioned article a plastic plant. That’s to say, anything that decorates the media with portraits of animals defined by fear, omitting to notice how important they are for humanity’s survival. Far from being ‘freaks of nature’ (as the journalist implies), here are five reasons sea urchins are important and extraordinary.
1. They are ancient
Sea urchins and their cousins sea stars were here long before humanity. Where I live in Port Phillip Bay we can fossick for 5-6 million year old heart urchins that are abundant in the fossil record. These are embedded in soft sediment that was laid down when the region was volcanic.
The above images are from Fossils of Beaumaris By Erich Fitzgerald and Rolf Schmidt, Museum Victoria.
In Komodo recently, we watched these charming heart urchins walking uncannily quickly over volcanic black sand. Also present were tusk worms and sand dollars (another type of sea urchin), which are also common in the fossil record.
Urchins first existed at a time when the Earth’s oceans were particularly nutrient-rich. This was before abundant large animal life had evolved. It’s unlikely that humans could have survived back then. But this point is rather moot when you consider we didn’t evolve for another 300 million years. The fact we still have sea urchins today is testament not only to their history but their ongoing importance for humanity. They exist for a reason and that is to maintain a habitable world for themselves. That just happens to also be the one we need to survive too.
2. They are grazing animals
Sea urchins are grazers, herbivores. As primary grazers they are critical to maintaining ecosystem balance. Removing abundant herbivores from an ecosystem is like claiming that wildebeest are a plague … but hang on. Here in Australia, we regard kangaroos as in plague proportions, despite the evidence that they are critical to rebuilding soil and water cycles. When it comes to heaping blame on wildlife for our ecological woes, Australia is a world leader in creating plastic plants.
If sea urchins are abundant today, it’s because they are still as relevant as they were 300 million years ago. The ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More they are part of are awash with nutrientsEnergy and nutrients are the same thing. Plants capture energy from the Sun and store it in chemicals, via the process of photosynthesis. The excess greenery and waste that plants create, contain chemicals that animals can eat, in order to build their own bodies and reproduce. When a chemical is used this way, we call it a nutrient. As we More and algae. This collapses the food chains that humans depend on, but urchins thrive in these situations. By removing them artificially, we are taking away the only viable solution to an impending collapse.
Not only that, they are critical to endangered ecosystems like temperate coral reefs and many of their populations are in a state of decline.
… echinoderms such as sea stars and sea urchins, have shown precipitous population declines over the past decade.
Dr Graham Edgar, March 23, 2023 The Conversation
3. They are long-lived
I was in a forum recently where government scientists were persuading people that we need to kill sea urchins. One enlightened citizen asked, ‘how long do they live for?’ The scientists couldn’t answer that fundamentally-important question. But another local said ‘they take about seven years to mature.’ Truth is, no-one really knows. Which means we are playing God, and tampering with creatures we barely understand.
According to Sullivan, ‘a PBS documentary [says] urchins can live for centuries and are “practically immortal”. Some species are, indeed, among the longest-lived animals on Earth.
Any animal that is long-lived has wisdom. That’s to say, an intelligence that’s developed in synchrony with its surrounding environment, that enables it to make survival decisions. If sea urchins still exist, it’s not because they are scoundrels that pillage the ecosystem, it’s because they’ve managed to build the system they can survive in. That same ecosystem is the one we evolved into. Lest we forget, the significance of these animals, to building a habitable world.
4. They are highly mobile
Mobility is a principle difference between animals and plants. Some sea urchins are sedentary. Others might move 5cm a minute but that’s significant on the spatial scale of a reef system. When we are looking at gatherings of sea urchins at one moment in time, we don’t consider the possibility that they move. But they do. The ability to shift location (like migratory wildebeest) makes them superior ecosystem engineers.
They are capable of browsing surplus vegetation that, if left unchecked, would collapse the surrounding ecosystem. When we ‘cull’ urchins, we take away this congregation tactic, which reduces their effectiveness. It can look like they are eradicating vegetation but that’s not because they are abundant, it’s because surplus energy is pouring into the system. That usually originates from human waste. The animals are responding by feeding and this will eventually restore the imbalance. Removing them increases the time it takes for ecosystems to recover and supports the establishment of invasive plants.
In this video a time lapse shows off the speed of sea urchins and their interesting communal behaviour.
5. They have a complex culture and biology
The very things that make urchins fascinating and ‘yuck’ for some people are the marvellous adaptations that have endured millions of years. Sullivan, in The Guardian describes how they there ‘a zombie state.’ It’s a bit like hibernation. They shut down and wait until conditions are right to start grazing again. This ability ensures that there is stock left to rebalance the catastrophic nutrient-enrichment of reefs.
Nurient overload is affecting almost every coastal reef in the world and, to a large degree, is caused by land-based agricultural run-off, plus the killing of large reef fish including other grazers and predators of urchins.
Urchins are incredibly sophisticated both biologically and culturally. Scientists have found that the entire urchin might act like a huge compound eye. They can detect chemical gradients in water to find food. Most intriguingly, they respond to each other. They can communicate and alter their behaviour and create ‘flocks’ that forage together.
Given their enormous sensory ability and long-lives, this development of a culture and cooperation, is essential. Such animals, that almost certainly feel pain (since they actively run away from predators), deserve a great deal more respect for their intense compatibility with functioning ecosystems.
Quite simply, they can do things we can never do ourselves. And we will never fully comprehend the level of sophistication by which they connect to, and restore the landscapes that we depend on.
They fortify ecosystems against collapse
According to the Merriam Webster dictionary, Manu Leumann suggested that the word ‘urchin’ may have originated in soldiers’ speech, with ērīcius/ēricius alluding originally not to a literal hedgehog, but rather an obstacle with sharpened ends used in fortifications.
It’s fitting when you consider the millions-year-old history of sea urchins. For as long as there have been humans, sea urchins have wandered the oceans. Whenever there were volcanic eruptions, ice-ages or other catastrophic instability in the biosphere, they would pick up the pieces and begin rebuilding. The structures they help create are called ecosystems and this defends us against collapse, providing a safe space for humans and other animals to live.
Which means our future depends on respecting them. Sullivan instead says ‘they are powerful. That they have a darkness.’
They are powerful, that much is true. The darkness comes from a place of fear. It’s a phobia. Like all phobias, it comes from a lack of knowledge. It propagates an almost supernatural hatred. There are few animals I know of that are more maligned than a sea urchin. Mosquitos perhaps. If turtles lacked their doughy-eyes, had spiny shells and were called ‘scoundrels’, I wonder if they’d be equally detested? They also occur in large numbers sometimes and they eat algae.
I knew nothing about sea urchins until quite recently. Now I watch them with fascination. I am in awe of their importance.
