This article was originally published on Surfline as part of their ‘Tooth and Claw’ series. You can see the original (illustrated with gorgeous images) on the Surfline website.
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Ever seen an actual seahorse? Maybe a seadragon washed up with weed after a swell? Here our fantastic Tooth and Claw correspondent, Dr Rebecca Olive, takes us into these very odd creatures’ lives, and lets us know why they matter more than you’d think.
Big animals like whales, dolphins and sharks get the attention, yet surfers and ocean swimmers often run into creatures far smaller and cuter: seahorses and seadragons.
With horse-like heads, monkey-like tails, and an amazing capacity for camouflage that includes looking like seaweeds and corals, these tiny critters are cuteness overload, and being so tricky to spot, are (I have heard) a delight to encounter.
Their popularity is reflected in the many ocean swimming groups who have adopted seahorses or seadragons as their moniker. This reference is more a tribute to local companionship than swimming skills, because everything I’ve read about them reports that they are comically terrible swimmers.
Like fish, seahorses and seadragons have a swim bladder, which helps them float and descend, but while seadragons have a few more fins to work with and a horizontal position that helps them move with a little more self-direction, seahorses are equipped with perfectly upright posture and one tiny fin on their back. This little fin beats 30-70 times per minute but still fails to propel them with any speed. Luckily, their grasping tail gives them grip to save them being washed away with the currents.
Of the 42-47 seahorse species found in various global waters (sources differ), 14 were only identified this century. When it comes to seadragons, there are only three species – the Common seadragon (also called the Weedy seadragon), the Leafy seadragon, and the newly described Ruby seadragon – all of which are found in the temperate waters of Australia.
All species numbers are in decline, with many species endangered.
Of course the most notorious fact about these adorable critters is that they are among the very, very few species of animals among which males gestate and birth the babies from their pouch (seahorses) or under their tail (seadragons).
Despite the romantics loving the idea, these animals don’t pair for life. Instead, they engage in a seasonal courtship of dancing and tail holding, until the mating work is done. Then the males bunker in place for the two to four weeks of gestation before releasing up to 100 fry. In the case of seadragons, this release is spectacular, with body convulsions shooting the fry out of the pouch and into the water.
There is a large part of me that wants to suggest there is something profound for us to learn from this sex-flip in birthing responsibilities. That there is something to say about patriarchy and biology and culture. But the truth is that male seahorse parents simply fertilise, gestate and birth the babies, with no parental care afterwards.
This might account for why the survival rate of seahorse fry is 0.5%! Unlike penguins, who co-parent through incubation and after the chick is hatched, seahorse parenting is not admirable or based in care. It’s functional.
Their low survival rate hints at the fragility of these coastal dwellers. While jellyfish are blooming in warming, polluted seas, seahorses are hugely impacted by anthropogenic climate change. Warming water, loss of sea grass and sea weeds, ocean plastics and overfishing have all contributed to a crisis for many species. These impacts are especially intense because they have a small habitat range and can’t easily survive changes in their environments.
With their terrible swimming skills, their inability to adapt to even slightly altered environments, and their complete lack of commitment to nurturing their young once they’re born, why should we care about the survival of these shallow water critters?
Because we are their main predator and threat.
If we’re going to fight to ensure the survival of charismatic megafauna like pandas, whales, and even koalas, then we best keep our eyes on the smaller critters that are equally at threat from the effects of humans on environments. In fact, this very sensitivity to their preferred ecologies is what seahorse conservation expert, Dr Xion Zhang, sees as the key to why we should fight for them.
Dr Zhang reminds us that since they aren’t able to survive significant environmental changes, their presence in coastal waters indicates a healthy ecosystem, which in turns suggests the other animals are doing okay too. In other words: seahorses may be coastal canaries in the aquatic coalmine.
Unlike sea horses and sea dragons, humans are adaptable to multiple environments and environmental changes. Our species’ adaptability is why we are able to maintain hope of enduring the changes being wrought by a warming planet, rising seas, increasing numbers of extreme weather events, and biodiversity loss.
But not all species will. Fighting to protect the animals most vulnerable to climate change helps us remember that small changes to environments are more serious than we imagined.
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If you choose, here’s a few ways you can support seahorse and seadragon conservation:
The Sydney Seahorse Project https://sims.org.au/research/flagship-projects/the-sydney-seahorse-project
Project Seahorse (International) https://projectseahorse.org/saving-seahorses/
Seadragon Search https://seadragonsearch.org/
