Great Atlantic Sargassum Belt
The Great Atlantic Sargassum Belt is a recurring Sargassum bloom in the Atlantic Ocean. It is the largest macroalgae bloom in the world.[2][3]
History
Mats of Sargassum in this region of the Atlantic are not new, having been reported as far back as the 15th century.[4] In the summer of 2011, a bloom large enough to be noticeable in satellite imagery appeared for the first time, and has appeared most summers since.[2][5]
In 2023, the belt was estimated to weigh about 5.5 million metric tonnes and extended 5,000 miles (8,000 km), stretching from West Africa to the Gulf of Mexico.[6][7] It was made of many individual patches, some up to an acre in surface area.[7]
Effects
During heavy blooms, the huge tangles of seaweed can ensnare larger wildlife like dolphins, sometimes fatally. Huge amounts of seaweed wash up on beaches, rotting and attracting insects. This interferes with fishing and tourism, negatively impacting communities across the Caribbean.[8] As beached Sargassum decomposes, it releases hydrogen sulfide gas. Hydrogen sulfide smells like rotting eggs, and can irritate the eyes and throat,[9] being particularly harmful to people with respiratory problems such as asthma.[10] Decomposing Sargassum also releases organic matter that decreases water quality near the shore. This buildup of organic matter leads to eutrophication.[11] Vibrio bacteria, which can cause necrotizing fasciitis in extreme cases, are found in large numbers in the mats of seaweed. The bacteria readily stick to Sargassum algae and the plastic debris that gets tangled in it.[12][13] Hydroids are also carried by Sargassum. They can cause issues for the fishing and aquaculture industries, as they are known to cause rashes in humans and can adapt to many different environments.[11]
Epibionts living on Sargassum alter naturally occurring seaweed and seagrasses that get washed up, which impacts habitats, food webs, and nutrient cycling.[11]
In 2022, the largest bloom on record was recorded, causing Guadeloupe to issue a health alert, as well as the US Virgin Islands issuing a state of emergency, requesting help from FEMA.
Cause
The buildup of Sargassum is caused by nutrients flowing into the Atlantic from water discharged by the Amazon and upwelling currents off West Africa. The algae does not originate from the nearby Sargasso Sea as was previously hypothesized, as the Sargassum mats found in that sea are composed of different morphological types of Sargassum than those that dominate the Sargassum Belt.[14]
The Sargassum Belt has also been found to possess lower biodiversity than the Sargasso Sea and is mainly composed of more highly nutrient-efficient organisms.
See also
References
- ^ López Miranda, José Luis; Celis, Lourdes B.; Estévez, Miriam; Chávez, Valeria; van Tussenbroek, Brigitta I.; Uribe-Martínez, Abigail; Cuevas, Eduardo; Rosillo Pantoja, Izarelly; Masia, Luis; Cauich-Kantun, Citlali; Silva, Rodolfo (November 12, 2021). "Commercial Potential of Pelagic Sargassum spp. in Mexico". Frontiers in Marine Science. 8. Frontiers Media SA. doi:10.3389/fmars.2021.768470. ISSN 2296-7745. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License Archived October 16, 2017, at the Wayback Machine.
- ^ a b Wang, Mengqiu; Hu, Chuanmin; Barnes, Brian B.; Mitchum, Gary; Lapointe, Brian; Montoya, Joseph P. (July 5, 2019). "The great Atlantic Sargassum belt". Science. 365 (6448): 83–87. Bibcode:2019Sci...365...83W. doi:10.1126/science.aaw7912. ISSN 0036-8075. PMID 31273122. S2CID 195804245. Archived from the original on March 17, 2023. Retrieved March 18, 2023.
- ^ Shao, Elena (April 19, 2023). "Those Seaweed Blobs Headed for Florida? See How Big They Are". The New York Times. ISSN 0362-4331. Retrieved April 19, 2023.
- ^ Wang, Mengqiu; Hu, Chuanmin; Barnes, Brian B.; Mitchum, Gary; Lapointe, Brian; Montoya, Joseph P. (2019). "The great Atlantic Sargassum belt". Science. 365 (6448): 83–87. doi:10.2307/26745329. ISSN 0036-8075.
- ^ Barberton, Zan (March 7, 2023). "The creeping threat of the Great Atlantic Sargassum Belt". The Guardian. ISSN 0261-3077. Archived from the original on March 18, 2023. Retrieved March 18, 2023.
- ^ "Outlook of 2023 Sargassum blooms in the Caribbean Sea and Gulf of Mexico" (PDF). University of South Florida. March 1, 2023. Archived (PDF) from the original on March 16, 2023. Retrieved March 18, 2023.
- ^ a b Gibbens, Sarah (March 16, 2023). "A giant, rotting mass of seaweed threatens beach season in the U.S." National Geographic. Archived from the original on March 18, 2023. Retrieved March 18, 2023.
- ^ Yong, Ed (July 4, 2019). "Why Waves of Seaweed Have Been Smothering Caribbean Beaches". The Atlantic. Archived from the original on March 16, 2023. Retrieved March 18, 2023.
- ^ Marchante, Michelle (March 17, 2023). "Miami Beach and the Keys could get loads of seaweed. It's smelly and can cause these symptoms". Miami Herald.
- ^ Coto, Dánica (August 3, 2022). "Record amount of seaweed is choking shores in the Caribbean". AP News. Archived from the original on December 10, 2022. Retrieved March 19, 2023.
- ^ a b c Rodríguez-Martínez, R. E.; Torres-Conde, E. G.; Rosellón-Druker, J.; Cabanillas-Terán, N.; Jáuregui-Haza, U. (April 1, 2025). "The Great Atlantic Sargassum Belt: Impacts on the Central and Western Caribbean–A review". Harmful Algae. 144: 102838. doi:10.1016/j.hal.2025.102838. ISSN 1568-9883.
{{cite journal}}: CS1 maint: article number as page number (link) - ^ Thomson, Jess (May 30, 2023). "Seaweed full of flesh-eating bacteria hitting Florida". Newsweek. Retrieved June 5, 2023.
- ^ Luscombe, Richard (June 3, 2023). "Clumps of 5,000-mile seaweed blob bring flesh-eating bacteria to Florida". The Guardian. ISSN 0261-3077. Retrieved June 5, 2023.
- ^ Schell, Jeffrey; Goodwin, Deborah; Siuda, Amy (September 1, 2015). "Recent Sargassum Inundation Events in the Caribbean: Shipboard Observations Reveal Dominance of a Previously Rare Form". Oceanography. 28 (3): 8–10. doi:10.5670/oceanog.2015.70. ISSN 1042-8275.