@article{34b206b6122f4e6baa1bb67427bea0b4,
title = "Photosynthetic energy conversion efficiency in the West Antarctic Peninsula",
abstract = "The West Antarctic Peninsula (WAP) is a highly productive polar ecosystem where phytoplankton dynamics are regulated by intense bottom-up control from light and iron availability. Rapid climate change along the WAP is driving shifts in the mixed layer depth and iron availability. Elucidating the relative role of each of these controls and their interactions is crucial for understanding of how primary productivity will change in coming decades. Using a combination of ultra-high-resolution variable chlorophyll fluorescence together with fluorescence lifetime analyses on the 2017 Palmer Long Term Ecological Research cruise, we mapped the temporal and spatial variability in phytoplankton photophysiology across the WAP. Highest photosynthetic energy conversion efficiencies and lowest fluorescence quantum yields were observed in iron replete coastal regions. Photosynthetic energy conversion efficiencies decreased by ~ 60% with a proportional increase in quantum yields of thermal dissipation and fluorescence on the outer continental shelf and slope. The combined analysis of variable fluorescence and lifetimes revealed that, in addition to the decrease in the fraction of inactive reaction centers, up to 20% of light harvesting chlorophyll-protein antenna complexes were energetically uncoupled from photosystem II reaction centers in iron-limited phytoplankton. These biophysical signatures strongly suggest severe iron limitation of photosynthesis in the surface waters along the continental slope of the WAP.",
author = "Jonathan Sherman and Gorbunov, {Maxim Y.} and Oscar Schofield and Falkowski, {Paul G.}",
note = "Funding Information: The authors thank the crew and support staff of ARSV Laurence M. Gould during LMG17‐01. We also thank Schuyler Nardelli and Naomi Shelton for help analyzing chlorophyll and nutrient concentrations, Robert Sherell and Kevin Wyman for comments on the manuscript, and two anonymous reviewers and Editor for constructive comments. This research was supported by NASA Ocean Biology and Biogeochemistry Program (grants NNX16AT54G and 80NSSC18K1416 to M.Y.G. and P.G.F.) and LTER Program of the US National Science Foundation (ANT‐0823101 to O.S.). J.S. is supported by a graduate fellowship from the Department of Marine and Coastal Sciences at Rutgers University. Funding Information: The authors thank the crew and support staff of ARSV Laurence M. Gould during LMG17-01. We also thank Schuyler Nardelli and Naomi Shelton for help analyzing chlorophyll and nutrient concentrations, Robert Sherell and Kevin Wyman for comments on the manuscript, and two anonymous reviewers and Editor for constructive comments. This research was supported by NASA Ocean Biology and Biogeochemistry Program (grants NNX16AT54G and 80NSSC18K1416 to M.Y.G. and P.G.F.) and LTER Program of the US National Science Foundation (ANT-0823101 to O.S.). J.S. is supported by a graduate fellowship from the Department of Marine and Coastal Sciences at Rutgers University. Publisher Copyright: {\textcopyright} 2020 The Authors. Limnology and Oceanography published by Wiley Periodicals LLC. on behalf of Association for the Sciences of Limnology and Oceanography.",
year = "2020",
month = dec,
doi = "10.1002/lno.11562",
language = "English (US)",
volume = "65",
pages = "2912--2925",
journal = "Limnology and Oceanography",
issn = "0024-3590",
publisher = "American Society of Limnology and Oceanography Inc.",
number = "12",
}