Since algae were the first form of life to appear on Earth, sargassum has inhabited the seas for millions of years. Chronologically, the following information provides an overview of the origin of this plant species and its presence in the Atlantic Ocean and throughout the Caribbean.
Existing for millions of years
In the Atlantic Ocean, the Sargassum drift has existed for millions of years. Although Christopher Columbus mentioned the presence of green algae in his journal during his voyage to the Indies, it is generally accepted that he repeatedly reported the presence of Sargassum banks when he reached the area now known as the «Sargasso Sea». The discovery of evidence of Sargassum’s existence has confirmed that it has been present for at least 444 to 419 million years (2).
The Sargasso Sea
The Sargasso Sea, also known as the «golden floating rainforest,» is located in the Atlantic Ocean near Bermuda. It covers an area of 1,000 km by 3,200 km, and the amount of Sargassum it contains is estimated at 10 million metric tons (3). Located at the center of major ocean currents known as ocean gyres, this area is characterized by a lack of waves and wind, where algae and drifting debris accumulate. (2). Nevertheless, clumps of Sargassum are constantly being released from this ocean gyre and scattered throughout the Atlantic (4).
Map: National Geographic: https://www.bibliotecapleyades.net/ciencia/esp_bermuda_04.htm
Stranding in the Caribbean
The literature indicates that the first major Sargassum algal blooms occurred in the Gulf of Mexico in 1864 (2). At that time, the strandings observed were much less severe in the Caribbean region (4), whereas since 2011, the phenomenon has reached considerable proportions in that region, as well as along the West African coast (2).
Following that first year of massive arrivals in the Caribbean region in 2011, new sightings were reported in 2012. The year 2013 brought a brief lull, but significant arrivals occurred in 2014 and were particularly high in 2015. A lull with modest quantities characterized 2016 (2) and 2017. Strandings gradually resumed in December 2017, and a «crisis» began in January 2018. An aerial survey to assess the distribution of algae across the region will soon make it possible to create a map on this subject (personal communication, F. Védié, DEAL).
In the Caribbean region, periods of significant strandings vary from year to year, but occur mainly between July and October (5). In Martinique, they particularly affect the Atlantic coast, but also the southern coast (1)
Mariska Desmarquis
References
1- ADEME, 2015. Collection and Utilization of Sargassum Seaweed in Martinique: Call for Expressions of Interest [Online PDF]: https://martinique.ademe.fr/sites/default/files/files/Accueil/ami-collecte-valorisation-algues-sargasses.pdf Page accessed on March 27, 2018.
2-French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 2017. Exposure to fumes from decomposing Sargassum seaweed in the French West Indies and French Guiana. [Online PDF]: https://www.anses.fr/fr/system/files/AIR2015SA0225Ra.pdf Page accessed on March 27, 2018.
3- Caribbean Hotel & Tourism Association, 2016. Sargassum: A Practical Guide for the Caribbean. Translated from English by Françoise Miranne-Parole and Nady Vial-Cabrera, Director of International Cooperation. DEAL Guadeloupe. [Online PDF]: http://www.guadeloupe.developpement-durable.gouv.fr/IMG/pdf/CAST_VF_pdf.pdf Page accessed on March 27, 2018.
4- DEAL Guadeloupe 2014, Sargassum Report [Online PDF]: http://www.ifrecor.com/documents/2014-note-sargasses-fmazeas-deal-unite-biodiversite-marine-maj-5fev2015.pdf Page accessed on March 27, 2018.
5- FLORENNE, T. and et al., 2016. The Phenomenon of Sargassum Drift in the Caribbean and French Guiana. French Government. [Online PDF]: http://cgedd.documentation.developpement-durable.gouv.fr/documents/cgedd/010345-01_rapport.pdf Page accessed on March 27, 2018.
