The secret world of seahorses

The secret world of seahorses

© Alexander Mustard

June 8th was World Oceans Day, this year celebrating the ocean: life and livelihoods. A healthy marine environment is essential to the functioning of our entire plant. We take a closer look at a weird and wonderful group of sea-dwelling species which can be found in the Solent – seahorses.

Up to 50% of the world’s oxygen is produced in the ocean, and our seas absorb around 30% of human-produced carbon dioxide. Without the oceans, the effects of climate change would be much more extreme. Oceans not only store carbon but also regulate temperature and drive weather systems. Millions of people depend on the marine environment for their main source of income, whether that is through fishing, tourism or shipping.

There are two species of seahorse found on the British coast, the spiny seahorse and the short-snouted seahorse. Both have been spotted off the Isle of Wight in the waters of the Solent. These strange creatures are a type of fish, they breathe through gills and have a swim bladder, but this is where the similarity to most other fish ends. Rather than scales, seahorses have armoured plates, and instead of using their tail as a rudder to propel them along, it acts more like an arm. Their tails can coil round fronds of sea plants, holding the seahorse in place when tides are strong or during rough weather. Their snouts are used for sucking in shrimp, their main food source.

In the summer months, seahorses will be mating, and again they do things a little differently to most species. Each morning, the female enters the male’s territory, and they will display to each other as part of their courtship, which can last up to an hour. Famously, it is the male that gets pregnant. He raises the young in a brood pouch for about a month before giving birth to some 300 tiny fry.   

Sadly, seahorses face several threats, including pollution, the pet and other illegal wildlife trades and habitat loss. They rely on seagrass beds to complete their life cycle, and these underwater meadows are being rapidly lost.

The Trust is currently running an exhibition at Portsmouth Museum – “spiny seahorses and ripping yarns”. The displays focus on marine litter and include a sculpture of a spiny seahorse made entirely from rubbish collected on local beaches. It is open daily until next spring, and it is free to enter, so make sure to head over and find out more.