Satellite Investigation of Drivers of Phytoplankton Composition in a Continental Shelf Ecosystem

Abstract

Phytoplankton size classes (PSCs) play an important role in ecological and biogeochemical processes in marine ecosystems. Studying the dynamics of phytoplankton groups and the environment can inform how we manage marine resources, including fisheries, which are of critical importance in the Northeast U.S. continental shelf ecosystem. This study aims to shed light on phytoplankton community structure distribution and the environmental drivers of their variability in the Northeast U.S. continental shelf from a satellite remote sensing perspective, which has a captivating ability to view the global ocean and its dynamics on large spatial scales and long-term temporal scales. 23 years (1997 to 2019) of imagery and reanalysis products were used to understand variability in the main drivers over time and applied an existing phytoplankton size classes algorithm to ocean color satellite products. The variables affecting the abundance and distribution of PSC in the Northeast U.S. continental shelf are diverse and intricately intertwined by season and region. Above all, chlorophyll-a concentration and euphotic depth are the most significant associations of all phytoplankton size class distribution in all seasons and regions, followed by salinity and mixed layer depth. Studying changes in such climate-forced phytoplankton community composition plays a crucial role in the management of energy and resources in the region from a fisheries perspective and in preparing for future climate change.