Remote sensing of phytoplankton community composition along the northeast coast of the United States

Abstract

Satellite imagery has proven to be a powerful tool for measuring chlorophyll a in surface waters. While this provides an estimate of total phytoplankton biomass, it does not distinguish between phytoplankton groups, many of which have functional differences and therefore affect biogeochemical cycles differently. Phytoplankton pigment analysis has been used to quantify a wide range of photosynthetic and accessory pigments, and chemotaxonomic analysis (e.g. CHEMTAX) has been used to successfully quantify functional taxonomic groups in nature based on pigment distributions. Here, we combine CHEMTAX analysis with satellite-derived distributions of specific phytoplankton pigments to describe the distributions of particular components of the phytoplankton community in the northeast coast of the United States from space. The spatial and seasonal variations in phytoplankton community structure elucidated through satellite remote sensing methods generally agreed with observations of abundance estimates of cell counts. Diatoms were generally the most abundant phytoplankton in this region, especially during Winter-Spring and in the inner shelf, but phytoplankton populations shifted to increasing abundance of other taxa during Summer, especially offshore. While still preliminary, satellite-derived taxa-specific information with proper regional controls holds promise for providing information on phytoplankton abundance to a taxonomic group level which would greatly improve our understanding of the impacts of human activity and climate change on ecosystems.

Temperature dependence of parasitoid infection and abundance of a diatom revealed by automated imaging and classification

“…This gradient in G. delicatula abundances follows the cross-shelf decline in phytoplankton and diatom biomass previously observed across the NES ( 19 – 22 ). These gradients are typically attributed to increased nutrient loading in the nearshore NES due to terrestrial and estuarine inputs ( 21 , 22 ), which likely contributes to the cross-shore gradient in G. delicatula abundances observed here. Conversely, cross-shore gradients in G. delicatula infection prevalence were not resolved here due to high uncertainty in offshore estimates.…”

Temperature dependence of parasitoid infection and abundance of a diatom revealed by automated imaging and classification

“…This gradient in G. delicatula abundances follows the cross-shelf decline in phytoplankton and diatom biomass previously observed across the NES ( 19 – 22 ). These gradients are typically attributed to increased nutrient loading in the nearshore NES due to terrestrial and estuarine inputs ( 21 , 22 ), which likely contributes to the cross-shore gradient in G. delicatula abundances observed here. Conversely, cross-shore gradients in G. delicatula infection prevalence were not resolved here due to high uncertainty in offshore estimates.…”

Cyanate distribution and uptake in North Atlantic coastal waters

“…comm.). While failure to detect cyanobacterial cynA does not unequivocally confirm its absence, these results combined with the dominance of eukaryotic phytoplankton in this system (Pan et al ) suggest that cyanate N was likely taken up by eukaryotes.…”

Testing a Hyperspectral, Bio‐Optical Approach to Identification of Phytoplankton Community Composition in the Chesapeake Bay Estuary

“…CHEMTAX‐based PCC proportions can be inconsistent compared to cell count‐based PCC, particularly for sub‐class level taxonomic identification (Armbrecht et al., 2015; Kozlowski et al., 2011; Latasa et al., 2022). At the class level, however, CHEMTAX‐based PCC fractions show significant correlation with cell count‐based PCC in the Chesapeake Bay (Harding et al., 2015), the nearby NW Atlantic (Pan et al., 2011), and studies across a variety of aquatic regimes (e.g., Kozlowski et al., 2011). Even with these uncertainties, past work and results of this study support application of CHEMTAX‐based PCC proportions as representative of in‐water PCC.…”

Temperature dependence of parasitoid infection and abundance of a diatom revealed by automated imaging and classification

“…This gradient in G. delicatula abundances follows the cross-shelf decline in phytoplankton and diatom biomass previously observed across the NES ( 19 – 22 ). These gradients are typically attributed to increased nutrient loading in the nearshore NES due to terrestrial and estuarine inputs ( 21 , 22 ), which likely contributes to the cross-shore gradient in G. delicatula abundances observed here. Conversely, cross-shore gradients in G. delicatula infection prevalence were not resolved here due to high uncertainty in offshore estimates.…”

Cyanate distribution and uptake in North Atlantic coastal waters

“…comm.). While failure to detect cyanobacterial cynA does not unequivocally confirm its absence, these results combined with the dominance of eukaryotic phytoplankton in this system (Pan et al ) suggest that cyanate N was likely taken up by eukaryotes.…”

Testing a Hyperspectral, Bio‐Optical Approach to Identification of Phytoplankton Community Composition in the Chesapeake Bay Estuary

“…CHEMTAX‐based PCC proportions can be inconsistent compared to cell count‐based PCC, particularly for sub‐class level taxonomic identification (Armbrecht et al., 2015; Kozlowski et al., 2011; Latasa et al., 2022). At the class level, however, CHEMTAX‐based PCC fractions show significant correlation with cell count‐based PCC in the Chesapeake Bay (Harding et al., 2015), the nearby NW Atlantic (Pan et al., 2011), and studies across a variety of aquatic regimes (e.g., Kozlowski et al., 2011). Even with these uncertainties, past work and results of this study support application of CHEMTAX‐based PCC proportions as representative of in‐water PCC.…”

Temperature dependence of parasitoid infection and abundance of a diatom revealed by automated imaging and classification

“…This gradient in G. delicatula abundances follows the cross-shelf decline in phytoplankton and diatom biomass previously observed across the NES ( 19 – 22 ). These gradients are typically attributed to increased nutrient loading in the nearshore NES due to terrestrial and estuarine inputs ( 21 , 22 ), which likely contributes to the cross-shore gradient in G. delicatula abundances observed here. Conversely, cross-shore gradients in G. delicatula infection prevalence were not resolved here due to high uncertainty in offshore estimates.…”

Cyanate distribution and uptake in North Atlantic coastal waters

“…comm.). While failure to detect cyanobacterial cynA does not unequivocally confirm its absence, these results combined with the dominance of eukaryotic phytoplankton in this system (Pan et al ) suggest that cyanate N was likely taken up by eukaryotes.…”

Testing a Hyperspectral, Bio‐Optical Approach to Identification of Phytoplankton Community Composition in the Chesapeake Bay Estuary

“…CHEMTAX‐based PCC proportions can be inconsistent compared to cell count‐based PCC, particularly for sub‐class level taxonomic identification (Armbrecht et al., 2015; Kozlowski et al., 2011; Latasa et al., 2022). At the class level, however, CHEMTAX‐based PCC fractions show significant correlation with cell count‐based PCC in the Chesapeake Bay (Harding et al., 2015), the nearby NW Atlantic (Pan et al., 2011), and studies across a variety of aquatic regimes (e.g., Kozlowski et al., 2011). Even with these uncertainties, past work and results of this study support application of CHEMTAX‐based PCC proportions as representative of in‐water PCC.…”