Impacts of Mesoscale Eddies on Phytoplankton Size Structure

Abstract

The impact of mesoscale eddies on phytoplankton communities attracts considerable research attention because phytoplankton play numerous roles in marine ecosystems. Using remote sensing techniques, this study considered a synoptic relationship between phytoplankton size structure, which is a determinant of energy transfer efficiency in marine ecosystems, and mesoscale eddies, which are ubiquitous ocean features. We found clear spatial variation in the impacts of mesoscale eddies on phytoplankton size structure; phytoplankton communities with larger cell sizes were supported by anticyclonic eddies in oligotrophic regions and by cyclonic eddies in eutrophic regions. Differences in the phytoplankton size structure within these two types of mesoscale eddies became greater, accompanied by interannual trends in the phytoplankton size structure for 2003–2014. Our findings are the first to demonstrate the important linkage between mesoscale eddies and phytoplankton size structure on a global scale; this new knowledge might help better predict variability in marine ecosystems.