Sinking Sargassum

Abstract

Blooms and coastal inundations of pelagic Sargassum have caused major problems to coastal communities and ecosystems throughout the tropical Atlantic over the past decade. Understanding Sargassum growth, movement, and mortality is essential to being able to predict and mitigate these events. In principle, tropical cyclones that occur in this area could have an impact on all three processes. In a recent article, Sosa-Gutierrez et al. (2022, https://doi.org/10.1029/2021GL097484) investigated the potential impacts of tropical cyclones (TCs) on pelagic Sargassum using satellite-based Sargassum maps and 86 hurricane tracks during 2011–2020. Their statistical analysis showed an average drop of 40% in Sargassum coverage under TC trajectories, which was attributed to possible sinking of Sargassum. Here, we discuss implications of these findings, and advocate continued research on how storms and other physical factors influence the dynamics of growth, movement, and mortality in this ecologically and economically important macroalgae.