Home
Weather Dublin
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
    Home / Editor's Pick /

    Marine heatwaves: Jellyfish thrive in the UK

08:00
11 November 2023

Marine heatwaves
Jellyfish thrive in the UK

Crystal jellyfish (Aequorea victoria) often found in warmer waters.
Crystal jellyfish (Aequorea victoria) often found in warmer waters. - © picture alliance

Jellyfish sightings in the UK have soared 32% in the last year, due to our warming waters.

From October 2022 to September 2023, jellyfish sightings have soared 32% along UK coasts. The bulk of these sightings have been on the UK's Atlantic west coast, particularly around Cornwall and Wales.

Species such as barrel jellyfish, Lion's mane, Portuguese man o' war, moon and compass jellyfish have all been spotted, including crystal jellyfish, which are more commonly known to warmer waters.

The hot weather in recent months, particularly in June, created marine conditions for the species to thrive in the UK.

Marine heatwaves

We're all familiar with the idea of a heatwave, but a marine heatwave is much less visible yet equally concerning. Marine heatwaves are periods of unusually warm ocean temperatures that can last anywhere from days to months.

Warmer waters due to marine heatwaves can severely impact marine ecosystems, creating nutrient-deficient "ocean deserts" that make it challenging for marine life to survive.

These temperature spikes are linked to a range of disruptions, from coral bleaching and altered fish migration patterns to the degradation of vital kelp forests along the coast.

That being said, it has led to a positive influx of new jellyfish species to UK coasts, though this could have knock-on implications on the marine ecosystem.

Scientists are unsure if the new species are a short-term result of the marine heatwaves, or a longer-term shift in their northward range as waters warm on average.

Oceans reach record high temperaturesread more
Weather & Radar editorial team
More on the topic
Extreme weather contrasts in Europe. Heat versus constant rain. . . Thursday 3 September 2026
On the left, the Temperature Radar shows high temperatures in Spain; on the right, the Weather Radar shows rain in Central Europe
Thursday 3 September 2026

Heat versus constant rain

Extreme weather contrasts in Europe
Rain and blustery winds spread. Frontal influence. . . Wednesday 2 September 2026
Split weather graphic showing widespread rain across the UK and Ireland alongside winds of 25-35 mph, strongest around Cardiff and the south of the UK.
Wednesday 2 September 2026

Frontal influence

Rain and blustery winds spread
A marked change in the weather. Cold front heading south. . Weather Videos. Monday 7 September 2026
Map of Europe showing a cold front stretching from Scandinavia to Spain. Thunderstorms are shown in southern and central Europe.
Weather VideosMonday 7 September 2026

Cold front heading south

A marked change in the weather
All weather news
This might also interest you
A stormy week in the skies above. Your weather - Your shots. . . Sunday 30 August 2026
Split image showing lightning branching beneath dark storm clouds above rooftops on the left and an orange-pink sunset over a calm sea on the right.
Sunday 30 August 2026

Your weather - Your shots

A stormy week in the skies above
Seasonal warmth between spring thunder. Your weather - Your shots. . . Sunday 19 April 2026
Split image showing coastal sunset with layered lenticular clouds over rooftops and palm trees on the left, and a green valley with river and hills under soft daylight on the right.
Sunday 19 April 2026

Your weather - Your shots

Seasonal warmth between spring thunder
Historic Storm Éowyn arrives. On this day.... . . Saturday 24 January 2026
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday 24 January 2026

On this day...

Historic Storm Éowyn arrives
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwitteryouTubelinkList