I’m always pleased to hear about interesting things other people have found around Cornwall especially from readers of this blog. I’ve been more than a touch jealous these last few weeks, however, of all the people finding Portuguese man o’war. They turn up occasionally in Cornwall but I’ve never seen one before and I feel like I’m missing my chance.
According to other people’s messages, Portuguese man o’war are everywhere and have been for weeks, covering strand lines, floating in pools, strewn on rocks everywhere from Penzance to Wales. And for weeks I’ve been searching and searching my local beaches and finding none. Until today.
It’s low tide and there are posts bouncing around social media saying that there are Portuguese man o’war around Looe. I have a house to clean, scones to make and blogs to write, so of course I drop everything and drag my other half and Junior to Hannafore beach.
I know they’ll be lifted off with each tide and battered and probably blown away with the next storm, so I’m not going to let this opportunity pass. Junior thinks I’ve gone mad though. He knows how powerful their sting is and insists, at first, that he’s not going near one.
His reluctance evaporates within a minute of arriving at the beach, when I find the first one. We all huddle round. The colours take me by surprise. In photos they always look a striking blue, but in real life they’re iridescent and seem to glow in the sun.
Apart from the colours, the float looks like a pasty to me (albeit a Devon one that’s been crimped along the top rather than the sides). The float is filled with carbon monoxide and other gases that the animal can adjust to control its buoyancy. Beneath the float, the tentacles form a blue stringy gloop on the rock.
Junior finds one afloat in a pool and I can’t resist taking a closer look. I slip on my yellow Marigolds – just in case – and scoop it up in my bucket.
As its tentacles unfurl, we get a better view of the animal – or rather the colony of organisms that make up this creature. The Portuguese man o’war is a siphonophore, so is not a jellyfish, but is made of many linked organisms that work together to survive.
Each organism within the colony has a job: forming the float, hunting prey, digesting food or reproducing. None of these different parts, known as zooids, can survive on its own so they rely on forming the colony – the Portuguese man o’war.
Close-up the long tentacles resemble a string of blue beads. Contained within them are many nematocysts, stinging cells that fire out powerful barbed harpoons full of poison to paralyse and trap prey.
We put the Portuguese man o’war in a pool and watch it blow from one side to the other. The float quickly rights itself, crimped side facing up, and catches the wind. The animal has no control over what direction it goes in, but it moves fast with the breeze behind it.
Only a very few specialised predators are able to eat them, such as the Logggerhead turtle and the Ocean sunfish. Depending on the winds, they can travel enormous distances in a lifetime before they blow onto a beach and perish. We find well over a dozen on a short stretch of shore.
It’s impossible to know how far these Portuguese man o’war have come to reach our shores or how long they’ll continue arriving, but mass strandings like this happen rarely in Cornwall.
I’m so pleased I haven’t missed this one.