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32 Per Cent Increase in Jellyfish Sightings Recorded by Marine Conservation Society

5th November 2023
Barrel jellyfish were the most common, according to the Marine Conservation Society's annual wildlife sightings report, with 467 sightings in total
Barrel jellyfish were the most common, according to the Marine Conservation Society's annual wildlife sightings report, with 467 sightings in total Credit: Tom Doyle

There was a 32 per cent increase in sightings of jellyfish around Irish and British waters over the past year, the Marine Conservation Society (MCS) says.

Barrel jellyfish were the most common, according to its annual wildlife sightings report, with 467 sightings in total.

Crystal jellies, comb jellies, and “sea gooseberries” accounted for about ten per cent of the total.

Cornwall and Wales recorded some of the highest figures for the period from October 2022 to September 2023.

As Afloat previously reported, barrel jellyfish which were normally only seen in waters off the southeast Irish coast, were reported last Mayo to be washing up in unusually large numbers along the entire coastline as far as Cork in the past few months.

Sightings were recorded by the National Biodiversity Data Centre (NBDC) from Lough Foyle on the north coast down to west Cork in the south with anecdotal reports of more, according to University College Cork scientist and jellyfish expert Dr Tom Doyle.

Lion's mane, Portuguese man o' war, moon and compass jellyfish were also recorded by the MCS, which has been asking the public to report sightings of jellyfish for the past 20 years.

It reported 12 turtle sightings, four being of the largest sea turtle, the leatherback.

Published in Marine Wildlife
Lorna Siggins

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Lorna Siggins

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Lorna Siggins is a print and radio reporter, and a former Irish Times western correspondent. She is the author of Search and Rescue: True stories of Irish Air-Sea Rescues and the Loss of R116 (2022); Everest Callling (1994) on the first Irish Everest expedition; Mayday! Mayday! (2004); and Once Upon a Time in the West: the Corrib gas controversy (2010). She is also co-producer with Sarah Blake of the Doc on One "Miracle in Galway Bay" which recently won a Celtic Media Award

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Marine Wildlife Around Ireland One of the greatest memories of any day spent boating around the Irish coast is an encounter with marine wildlife.  It's a thrill for young and old to witness seabirds, seals, dolphins and whales right there in their own habitat. As boaters fortunate enough to have experienced it will testify even spotting a distant dorsal fin can be the highlight of any day afloat.  Was that a porpoise? Was it a whale? No matter how brief the glimpse it's a privilege to share the seas with Irish marine wildlife.

Thanks to the location of our beautiful little island, perched in the North Atlantic Ocean there appears to be no shortage of marine life to observe.

From whales to dolphins, seals, sharks and other ocean animals this page documents the most interesting accounts of marine wildlife around our shores. We're keen to receive your observations, your photos, links and youtube clips.

Boaters have a unique perspective and all those who go afloat, from inshore kayaking to offshore yacht racing that what they encounter can be of real value to specialist organisations such as the Irish Whale and Dolphin Group (IWDG) who compile a list of sightings and strandings. The IWDG knowledge base has increased over the past 21 years thanks in part at least to the observations of sailors, anglers, kayakers and boaters.

Thanks to the IWDG work we now know we share the seas with dozens of species who also call Ireland home. Here's the current list: Atlantic white-sided dolphin, beluga whale, blue whale, bottlenose dolphin, common dolphin, Cuvier's beaked whale, false killer whale, fin whale, Gervais' beaked whale, harbour porpoise, humpback whale, killer whale, minke whale, northern bottlenose whale, northern right whale, pilot whale, pygmy sperm whale, Risso's dolphin, sei whale, Sowerby's beaked whale, sperm whale, striped dolphin, True's beaked whale and white-beaked dolphin.

But as impressive as the species list is the IWDG believe there are still gaps in our knowledge. Next time you are out on the ocean waves keep a sharp look out!