Home / Weather News /

Sargassum threatens: A blob larger than the US in Atlantic

06:00
16 March 2023

Sargassum threatens
A blob larger than the US in Atlantic

Sargassum covering a beach in Barbados in summer of 2022.Sargassum covering a beach in Barbados in summer of 2022. - © picture alliance

Seaweed often smells bad and creates inconveniences for the little ones trying to play on the sand. But is it harmful?

Florida beaches have been especially affected in recent years by an influx of seaweed, as the warmer waters and wind currents have brought more of this sargassum to the beaches.

Sargassum is a type of brown algae that takes a very long time to sink to the bottom of the sea and travels in large masses on the surface of the sea.

Many animals feed and live in the sargassum that often travels cross-continent. But once it loses buoyancy, the algae sinks to the sea floor, becoming a food source for other animals.

However there is currently a large mass of sargassum travelling west over the Atlantic. This mass is wider than the United States, covering over 8000 km. Scientists expect that if this sargassum reaches the Florida coast, it will be around June.

In recent weeks, Key West has experienced rafts of it. Southwest Florida is also at threat of receiving mass amounts, but from the Yucatan Peninsula, which has also experienced gigantic amounts of sargassum in recent years.

Is it harmful?

Sargassum floating on the sea is not harmful, but does become a nuisance piling up on the beach. As the algae rot however, it releases hydrogen sulphide, which is often harmful to our respiratory systems.

Large amounts of seaweed can also block waterways. During summer 2022, an unusually large amount of sargassum caused water shortages in St. Croix, which prompted a state of emergency for the U.S Virgin Islands.

Weather & Radar editorial team
More on the topic
pinecones
Thursday, 11 December 2025

Winter helpers

How pine cones aid the weather forecast
The weather map shows extremely low temperatures in Canada.
Monday, 15 December 2025

Minus 53 degrees

Record cold in Canada's Yukon Territory
Map comparison showing 44 degrees in Indulkana and minus 51 degrees in Olenyok. Coloured temperature ranges show stark global contrasts.
Tuesday, 9 December 2025

Global extremes

Almost 100 degrees difference in temperature
All weather news
This might also interest you
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
plit image showing a double rainbow over a rocky shoreline on the left and sheep grazing in a green field under stormy clouds on the right.
Sunday, 2 November 2025

Your weather - Your shots

Mixed conditions on an unsettled week
Friday, 22 August 2025

Breakfast brief

Sunny start for some, overcast later
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