Unprecedented summer phytoplankton bloom in the Ross Sea

Esther Portela; Meredith G. Meyer; Karen J. Heywood; Walker O. Smith

doi:10.1029/2024GL111264

Unprecedented summer phytoplankton bloom in the Ross Sea

Esther Portela, Meredith G. Meyer, Karen J. Heywood, Walker O. Smith

Research output: Contribution to journal › Article › peer-review

Abstract

High-resolution glider sampling in the southwestern Ross Sea revealed an extensive phytoplankton bloom in austral summer 2022–2023 that persisted for over one month and extended through the upper 100 m of the water column. The temporal mean euphotic-zone chlorophyll concentration was 20.3 (Formula presented.) 8.5 (Formula presented.), six to nine times higher than average summer Ross Sea concentrations. The bloom was likely initially dominated by Phaeocystis, favored over diatoms due to low light and high iron availability. Our observations are consistent with an ice-edge bloom likely fueled by iron supply and enhanced stratification from late sea-ice melt during an anomalously high ice-covered summer. Photoacclimation to particularly low light conditions might have enhanced Chl-a fluorescence. In the Ross Sea, the most productive region in the Southern Ocean, understanding the drivers of this extreme bloom is crucial for predicting potential impacts of the changing climate on primary production rates and carbon sequestration.

Original language	English
Article number	e2024GL111264
Journal	Geophysical Research Letters
Volume	52
Issue number	3
Early online date	3 Feb 2025
DOIs	https://doi.org/10.1029/2024GL111264
Publication status	Published - 16 Feb 2025

Keywords

glider survey
phytoplankton bloom
Ross Sea

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1029/2024GL111264Licence: CC BY

Portela_etal_2025_GeophysicalResearchLettersFinal published version, 2.29 MBLicence: CC BY

Cite this

@article{c32dc499e5c548f1b4175c023f0d0153,

title = "Unprecedented summer phytoplankton bloom in the Ross Sea",

abstract = "High-resolution glider sampling in the southwestern Ross Sea revealed an extensive phytoplankton bloom in austral summer 2022–2023 that persisted for over one month and extended through the upper 100 m of the water column. The temporal mean euphotic-zone chlorophyll concentration was 20.3 (Formula presented.) 8.5 (Formula presented.), six to nine times higher than average summer Ross Sea concentrations. The bloom was likely initially dominated by Phaeocystis, favored over diatoms due to low light and high iron availability. Our observations are consistent with an ice-edge bloom likely fueled by iron supply and enhanced stratification from late sea-ice melt during an anomalously high ice-covered summer. Photoacclimation to particularly low light conditions might have enhanced Chl-a fluorescence. In the Ross Sea, the most productive region in the Southern Ocean, understanding the drivers of this extreme bloom is crucial for predicting potential impacts of the changing climate on primary production rates and carbon sequestration.",

keywords = "glider survey, phytoplankton bloom, Ross Sea",

author = "Esther Portela and Meyer, {Meredith G.} and Heywood, {Karen J.} and Smith, {Walker O.}",

note = "Data Availability Statement: The glider data used in this study (doi:10.5285/0a1c43b9-4738-75e0-e063-6c86abc0ea24) are available at (Portela et al., 2024) and from British Oceanographic Data Centre (BODC) https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/0a1c43b9-4738-75e0-e063-6c86abc0ea24. The longterm SIC data can be found at (https://data.seaice.uni-bremen.de/amsr2/asi_daygrid_swath/s3125/). Wind speed data were obtained from ERA5 (Hersbach et al., 2018) at (https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=overview), and satellite AQUA-MODIS PAR data (NASA Ocean Biology Processing Group, 2018) can be found here https://oceandata.sci.gsfc.nasa.gov/directdataaccess/Level-3%20Binned/Aqua-MODIS. Acknowledgments: We thank the Natural Environment Research Council (NERC), National Science Foundation (NSF), and McMurdo Station staff for funding and logistical support. The authors were supported by NSFGEO-NERC collaborative project P2P: Plankton to Predators—Biophysical Controls in Antarctic Polynyas (PI David Ainley, NSF grant ANT-2040571 and NERC grant NE/W00755X/1). The glider campaign was further supported by COMPASS: Climate-relevant Ocean Measurements and Processes on the Antarctic Continental Shelf and Slope (European Research Council, Horizon 2020: Grant 741120). We thank Gillian Damerell and Gareth Lee for their work in glider deployment and set up, and the UEA glider science team for glider piloting.",

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doi = "10.1029/2024GL111264",

language = "English",

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N2 - High-resolution glider sampling in the southwestern Ross Sea revealed an extensive phytoplankton bloom in austral summer 2022–2023 that persisted for over one month and extended through the upper 100 m of the water column. The temporal mean euphotic-zone chlorophyll concentration was 20.3 (Formula presented.) 8.5 (Formula presented.), six to nine times higher than average summer Ross Sea concentrations. The bloom was likely initially dominated by Phaeocystis, favored over diatoms due to low light and high iron availability. Our observations are consistent with an ice-edge bloom likely fueled by iron supply and enhanced stratification from late sea-ice melt during an anomalously high ice-covered summer. Photoacclimation to particularly low light conditions might have enhanced Chl-a fluorescence. In the Ross Sea, the most productive region in the Southern Ocean, understanding the drivers of this extreme bloom is crucial for predicting potential impacts of the changing climate on primary production rates and carbon sequestration.

AB - High-resolution glider sampling in the southwestern Ross Sea revealed an extensive phytoplankton bloom in austral summer 2022–2023 that persisted for over one month and extended through the upper 100 m of the water column. The temporal mean euphotic-zone chlorophyll concentration was 20.3 (Formula presented.) 8.5 (Formula presented.), six to nine times higher than average summer Ross Sea concentrations. The bloom was likely initially dominated by Phaeocystis, favored over diatoms due to low light and high iron availability. Our observations are consistent with an ice-edge bloom likely fueled by iron supply and enhanced stratification from late sea-ice melt during an anomalously high ice-covered summer. Photoacclimation to particularly low light conditions might have enhanced Chl-a fluorescence. In the Ross Sea, the most productive region in the Southern Ocean, understanding the drivers of this extreme bloom is crucial for predicting potential impacts of the changing climate on primary production rates and carbon sequestration.

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Unprecedented summer phytoplankton bloom in the Ross Sea

Abstract

Keywords

UN SDGs

Access to Document

Other files and links

NSFGEO-NERC Collaborative, P2P: Predators to Plankton — Biophysical Controls in Antarctic Polynyas

Seaglider data from the Western Ross Sea, Antarctica, November 2022-January 2023

Cite this

Unprecedented summer phytoplankton bloom in the Ross Sea

Abstract

Keywords

UN SDGs

Access to Document

Other files and links

Projects

NSFGEO-NERC Collaborative, P2P: Predators to Plankton — Biophysical Controls in Antarctic Polynyas

Datasets

Seaglider data from the Western Ross Sea, Antarctica, November 2022-January 2023

Cite this