Hindcasting the 2017 dispersal of Sargassum algae in the Tropical North Atlantic

TitleHindcasting the 2017 dispersal of Sargassum algae in the Tropical North Atlantic
Publication TypeJournal Article
Year of Publication2020
AuthorsBerline, L, Ody, A, Jouanno, J, Chevalier, C, André, J-M, Thibaut, T, Ménard, F
JournalMarine Pollution Bulletin
Volume158
Pagination111431
ISSN0025-326X
KeywordsAFAI, Aggregation, Annual cycle, distribution, Forecast, Lagrangian transport, MODIS
Abstract

Since 2011, huge amounts of Sargassum algae are detected in the equatorial Atlantic, causing large strandings events on the coasts of the West Indies, Brazil and West Africa. The distribution of this stock shows strong annual and interannual variability, whose drivers are not settled yet. Here we use satellite Sargassum observations from MODIS and currents from an ocean reanalysis to simulate the passive transport of algae in 2017. Wind effect was necessary to fit the observed distribution. Simulations reasonably reproduce the satellite monthly distribution for up to seven months, confirming the prominent role of transport in the distribution cycle. Annual cycle appears as a zonal exchange between eastern (EAR) and western accumulation regions (WAR). EAR is well explained by advection alone, with sharp meridional distribution controlled by converging currents below the inter-tropical Convergence Zone. Instead, WAR is not explained by advection alone, suggesting local growth.

URLhttp://www.sciencedirect.com/science/article/pii/S0025326X2030549X
DOI10.1016/j.marpolbul.2020.111431