April and Jellyfish …

Yes folks, time to warn you all. Spring has been well and truly under-way in the ocean for some time now. The dead give-away is the deepening green of the water indicating the first and largest plankton blooms. (Note the banner colour of my blog again!).

Early “action” isn’t particularly visible but the next most visible sign for us in the South and South East is the April jellyfish explosion. One day none, next day everywhere (if you are unlucky).

The last few years it’s been the third or fourth week of April that they become obvious when we get the big blooms.

So, in Tramore Bay, we have the cold water current coming in on the west (swimming) side of the bay. Jellies generally drift and only adjust height/depth in water. So many will come in on the current. And the bay is deep enough to hold jellies at all tides.

  • So, before it happens, watch out for days with South Easterlies or Easterly winds. These will cause large masses of jellies to accumulate around our side of the bay. The jellies will last a day or two AFTER these conditions also.

The area that seems worst is between the Guillamemes and Colomene rock, and about halfway from the Colomene to the Pier.

(Funnily enough the same conditions pertain to Baile Na Gaul to Helvick Head, but the water is shallower so it’s not as bad. Between Helvick Pier and Helvick Head, behind the small island, is the worst.)

The Open Water Swimming Association did a poll of things OW swimmers most disliked/feared and jellies/stingray were 2nd on the list after sharks. (Obviously mostly warm water swimmers!).

So the good news:

MOST JELLIES ARE HARMLESS (from an Irish South Coast point of view anyway).

A swimmers adage is, ‘it’s the jellyfish you don’t see that will get you”.

The Moon/Common jellyfish is just that, most common, and doesn’t sting (thought the guide says it has apparently a mild sting). “Moon” because it’s a translucent white. Jack-by-the-wind (Jack-the-Sailor) are also harmless.

So…jellyfish and jellyfish stings.

  • Don’t panic.
  • Reactions vary by person. But most people will find jelly stings cause no more than mild brief discomfort.
  • The initial sting will be sharp, like a nettle sting. For myself, Purple and Blue Stinger strikes taper off very quickly and last only about 10 minutes of a tingling sensation. Portugese Man O’War is much worse and lasts for up to 4 to 5 hours.
  • Sea-water, luckily, dulls stings, so you might as well stay in the water anyway.
  • If you do get stung a lot, and have a greater reaction, it’s good to know what to do.
  • Don’t touch the sting. No rubbing with a towel or scratching.
  • Always carry vinegar with your swim gear. Douse the area with vinegar. Don’t have a fresh water shower until well after the sting has abated. (You can get stung in the winter but it’s unlikely as the jellies will be lower down)
  • Scraping a stung area with something straight like the edge of a bank card will also remove some of the barbules.

(Save yourself learning the hard way, like I did and transfer the vinegar immediately to a plastic bottle, rather than leaving it in the glass bottle, which WILL break and you will smell like a chip shop).

A jellyfish sting is actually a collection of barbules which have venom in them. Vinegar will stop those barbs firing which are in your skin but haven’t yet fired. Those barbs which have already fired will not be affected by the vinegar. As I said above delay having a shower. Fresh water will cause the stings to feel worse.

There are jellyfish sting creams available, (though not widely in Ireland). Danny says he tried one (Safe Sea) which he got in work and it was good. Anti-histamines should work as well if you have a particularly bad reaction.

But let me stress again, there’s not that much to worry about. I was stung about 40 times in a 3k Helvick swim a few years ago, and I could only tell because I could count the visible stings afterwards. I only actually felt a few of them, and they weren’t bad.

We get occasional Lion’s Mane jellies in the South-east later in the summer which have a worse sting , but they are very noticeable because they get quite large, are infrequent, so easy to avoid, and I’ve only seen them out around the Metalman and further.

Purple and Compass jellies are the two I dislike most but are not a problem at this time of the year.


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