That familiar fear. It nestles in the pit of the stomach, lying dormant for the winter months. Now that the summer’s here (sort of), the horror is revisited. The sea is cold but that’s not what’s playing on your mind. Muscles tense, eyes scan the water for movement – like that guy in Jaws. Roy Scheider, wasn’t it? Yes, I think that was his name. Good actor. Poor guy, I think he’s dead now. It’s useless – your mind can’t ignore it for much longer. Was that one? No, just some seaweed. It’s too much to bear and you retreat, slowly at first. Then you make a run for it. Ah, the sand is so much more fun. Yes, folks, that’s right – jellyfish season is upon us once again.
Though most of our knowledge of jellyfish has come about from flinging stones at them on the beach as children, you’ll be glad to know that it’s not all a horror show. My sisters and I used to mince them up before applying a sand marinade as a delicacy for our parents, who, needless to say, politely declined our culinary offering.
Employed in marine research, I have worked a lot on jellyfish and I can attest that the truth behind these strange, ancient creatures is much less dramatic than many would care to believe. Well, that depends on what you consider dramatic, for the news on jellyfish is both good and bad.
Let’s begin with the good news: jellyfish are not dangerous. In fact they don’t all sting. I must qualify that by saying in fact they all sting – otherwise they wouldn’t be jellyfish (the ability to sting defines the group of animals to which they belong). What I mean is they don’t all have the ability to sting humans. In fact the most common species in Irish waters, the Moon jellyfish, identified by its four purple rings (actually reproductive organs), is pretty much harmless. An encounter with one may result in a mild irritation, much like brushing off of some overgrown ferns. Ignoring the infrequent Portuguese Man-O-War that drifts up now and again from sunnier climes, around the Cork coast there are really only two species that sting bathers: the Compass jellyfish and the Blue jellyfish. The Compass is very striking and is by far the prettiest of all species. Its bell is adorned with a beautiful brown radial pattern. Long frilly tentacles flow out like woven silk in the water. Its sting is nothing worse than that of a nettle. The Blue jelly, admittedly, can give a bit of a whack, but yet nothing more unsettling than a bee sting.
Its larger and more infamous cousin, the Lion’s Mane, has had people swimming for their lives up in the Forty Foot in Dublin. The Lion’s Mane has resulted in several hospitalisations, and some years back resulted in several beach closures in Dublin due to their abundance and reputation as nasty, sting-slinging loners of the sea. Much of my work has involved the Lion’s Mane, and I can say that this reputation is only partly deserved. We have snorkelled with them to attach electronic tags, and as long as a wetsuit is donned and Vaseline applied to exposed skin, then swimming with them is a truly marvellous experience. In the eerily silent world beneath the waves, the slow graceful movement of the jellyfish is at times operatic. It twists and turns and pulsates with the slow rhythm of a mournful orchestra. For an animal without a brain or a heart this is remarkable behaviour. Its huge tentacles make it the longest of any jellyfish species in the ocean, and some suggest it may be the longest of all marine species.
Now for the bad news: it remains to be proven but all the evidence is pointing to the fact that jellyfish are on the rise. It is believed that they are able to thrive in both polluted and warmer waters, both of which are growing concerns. With global fish stocks being eroded each year it is possible that jellyfish are exploiting food resources that they once would have competed for with fish. Given that jellyfish are around 500 million years old it is no wonder that their survival mechanisms are neatly honed. The fear, however, is that one day in the not too distant future our oceans could be transformed into a jelly soup, one in which the ecological balance has been tipped irrevocably. As jellyfish are not a harvestable food source (they are over 95% water) this is truly bad news. Some scientists have even put a name on this dystopian vision: the jellyfish joyride. One in which there is no way back for fish.
Okay, I’ll admit this is pretty grim stuff. Maybe what we need after all is a Roy Scheider. An eagle-eyed, stern-faced patrol man warning of the imminent danger, eternally hopping nervously from one foot to the other. And great big jellyfish nets to keep the critters off our beaches. Don’t laugh. In parts of Australia this is already happening. Admittedly the Aussie jellies make our ones look like the Dalai Lama on mushrooms, but with the growing hysteria surrounding jellyfish in Ireland (go to the Forty Foot some day and you’ll see what I mean), and the likelihood of increasing swarms, it may not be long before local authorities have to take action to keep people swimming in our waters.
So the next time you’re at the beach, try to ignore this dire forecast of jelly infestation. Man up, as they say. It’s like being attacked by a swimming breast implant. Try instead to marvel at these weird and wonderful animals. They have dwelled in this world for much longer than we have. And they will dwell in it long after we have gone.