Home
Weather London
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Career
    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
Super typhoon near the Philippines. Gusts of up to 155 mph. . . Tuesday, 23 June 2026
WindRadar showing Typhoon MEKKHALA east of Taiwan. A clearly visible eye, surrounded by areas of extremely high wind speeds.
Tuesday, 23 June 2026

Gusts of up to 155 mph

Super typhoon near the Philippines
Record-breaking heatwave in Europe. New records. . . Thursday, 25 June 2026
A map showing extremely high temperatures across Western Europe and a warning symbol. On the right, people cool off at a fountain in front of the Eiffel Tower during the heatwave in Paris.
Thursday, 25 June 2026

New records

Record-breaking heatwave in Europe
June temperature record broken again. Three days running. . . Friday, 26 June 2026
Temperature map of eastern England showing extreme heat around Ipswich and nearby areas, with temperatures reaching 36°C near Cambridge and a large red thermometer icon highlighting intense heat.
Friday, 26 June 2026

Three days running

June temperature record broken again
All weather news
This might also interest you
Storm Benjamin impacts the UK. Warnings active. . . Wednesday, 22 October 2025
Split weather map showing UK wind speeds in orange-red shades up to 40 mph on the left and warning levels in green-yellow on the right, with a central wind warning sign.
Wednesday, 22 October 2025

Warnings active

Storm Benjamin impacts the UK
New records for England and Wales. Broken again tomorrow?. . . Thursday, 25 June 2026
Temperature map of southwest Britain on 25.06 showing extreme heat across southern Wales and southwest England, with Bute Park in Cardiff highlighted at 34.2°C and Yeovilton at 36.4°C amid widespread deep red heat zones.
Thursday, 25 June 2026

Broken again tomorrow?

New records for England and Wales
Flooding, gales, and heavy snow. Storm Chandra. . . Tuesday, 27 January 2026
Split image showing aerial flooding in a town with muddy water covering roads on the left, and a rural road on the right blocked by heavy snowfall with vans stopped and a person walking in snow.
Tuesday, 27 January 2026

Storm Chandra

Flooding, gales, and heavy snow
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

facebooktwittertikToklinkList