Nicolas Cassar

About

Nicolas Cassar is the Lee Hill Snowdon Professor of Biogeochemistry and a faculty member in the Earth and Climate Sciences at the Nicholas School of the Environment at Duke University. His research focuses on environmental biogeochemistry and physiology, with the aim of constraining the mechanisms governing carbon cycling and climate. His current research interests include ocean carbon cycles and productivity, carbon acquisition mechanisms in marine phytoplankton and their implications for climate change and paleo-CO2 reconstruction, as well as global carbon cycle and ocean-atmosphere fluxes. Cassar's scientific approach is interdisciplinary, integrating field observations, laboratory experiments, modeling, and theory to address these complex environmental processes.

Research topics

• Oceanography
• Ecology
• Environmental science
• Geology
• Geography
• Biology
• Mathematics
• Physics
• Meteorology
• Animal science

Selected publications

• Widespread phytoplankton blooms triggered by 2019–2020 Australian wildfires

  Nature · 2021 · 255 citations

  Senior authorCorresponding
  DOI

• An operational overview of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Northeast Pacific field deployment

  Elementa Science of the Anthropocene · 2021 · 66 citations

  The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean S…

  DOI

• Decline in plankton diversity and carbon flux with reduced sea ice extent along the Western Antarctic Peninsula

  Nature Communications · 2021 · 58 citations

  Senior authorCorresponding

  Since the middle of the past century, the Western Antarctic Peninsula has warmed rapidly with a significant loss of sea ice but the impacts on plankton biodiversity and carbon cycling remain an open question. Here, using a 5-year dataset of eukaryotic plankton DNA metabarcoding, we assess changes in biodiversity and net community production in this region. Our results show that sea-ice extent is a dominant factor influencing eukaryotic plankton community composition, biodiversity, and net commun…

  DOI

• Phytoplankton size-class contributions to new and regenerated production during the EXPORTS Northeast Pacific Ocean field deployment

  Elementa Science of the Anthropocene · 2022 · 35 citations

  The NASA EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) program was established to better quantify the pathways of the biological carbon pump in order to gain a more comprehensive understanding of global carbon export efficiency. The summer 2018 field campaign in the vicinity of Ocean Station Papa (Station P; 50°N, 145°W) in the Northeast Pacific Ocean yielded evidence of low phytoplankton biomass and primary productivity dominated by small cells (<5 µm) that are reliant on r…

  DOI

• Greener green and bluer blue: Ocean poleward greening over the past two decades

  Science · 2025-06-19 · 15 citations

  articleSenior authorCorresponding

  Although the global greening associated with climate change is well documented on land, similar trends in the ocean have not been thoroughly identified. Using satellite observations of ocean chlorophyll a (Chl) concentration, we show that the surface ocean experienced a poleward greening from 2003 to 2022. Contemporaneously, the subtropical regions of the Northern Hemisphere experienced a decrease in Chl. As such, the latitudinal disparity in Chl, as documented by an inequality index, has been i…

  PublisherDOI

Recent grants

• PHYSIOLOGICAL AND ECOSYSTEM STRUCTURE FORCINGS ON CARBON FLUXES IN THE SOUTHERN OCEAN MIXED LAYER

  NSF · $492k · 2011–2015

• CAREER: Method Development for High-Resolution Underway N2 Fixation Measurements

  NSF · $790k · 2014–2021

• EAGER: Method development for the assessment of spatiotemporal variability of non-symbiotic N2 fixation

  NSF · $248k · 2011–2013

Frequent coauthors

• Yajuan Lin

  267 shared

• Hugo Berthelot

  Institut Universitaire Européen de la Mer

  224 shared

• Stéphane L’Helguen

  Institut de Recherche pour le Développement

  168 shared

• Jean‐François Maguer

  Laboratoire des Sciences de l'Environnement Marin

  168 shared

• Hélène Planquette

  Laboratoire des Sciences de l'Environnement Marin

  73 shared

• Weiyi Tang

  Princeton University

  71 shared

• Éric Gilson

  Gilson (France)

  62 shared

• Éric Douville

  62 shared

Awards & honors

• Lee Hill Snowdon Professor of Biogeochemistry (2025)

Similar researchers at Duke University

• James S. Clarkh-93
• Emily Bernhardth-84
• Patrick Halpinh-62