Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification

Marine multicellular organisms inhabiting waters with natural high fluctuations in pH appear more tolerant to acidification than conspecifics occurring in nearby stable waters, suggesting that environments of fluctuating pH hold genetic reservoirs for adaptation of key groups to ocean acidification...

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Published in:Biogeosciences
Main Authors: Von Dassow, P, Díaz-Rosas, F, Bendif, E, Gaitán-Espitia, J, Mella-Flores, D, Rokitta, S, John, U, Torres, R
Format: Article in Journal/Newspaper
Language:English
Published: European Geosciences Union 2020
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Online Access:https://doi.org/10.5194/bg-15-1515-2018
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spelling ftuloxford:oai:ora.ox.ac.uk:uuid:da38dfa6-a3c7-4ae2-8dab-aff75322513e 2023-05-15T17:50:48+02:00 Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification Von Dassow, P Díaz-Rosas, F Bendif, E Gaitán-Espitia, J Mella-Flores, D Rokitta, S John, U Torres, R 2020-01-08 https://doi.org/10.5194/bg-15-1515-2018 https://ora.ox.ac.uk/objects/uuid:da38dfa6-a3c7-4ae2-8dab-aff75322513e eng eng European Geosciences Union doi:10.5194/bg-15-1515-2018 https://ora.ox.ac.uk/objects/uuid:da38dfa6-a3c7-4ae2-8dab-aff75322513e https://doi.org/10.5194/bg-15-1515-2018 info:eu-repo/semantics/openAccess CC Attribution (CC BY) CC-BY Journal article 2020 ftuloxford https://doi.org/10.5194/bg-15-1515-2018 2022-06-28T20:25:28Z Marine multicellular organisms inhabiting waters with natural high fluctuations in pH appear more tolerant to acidification than conspecifics occurring in nearby stable waters, suggesting that environments of fluctuating pH hold genetic reservoirs for adaptation of key groups to ocean acidification (OA). The abundant and cosmopolitan calcifying phytoplankton Emiliania huxleyi exhibits a range of morphotypes with varying degrees of coccolith mineralization. We show that E. huxleyi populations in the naturally acidified upwelling waters of the eastern South Pacific, where pH drops below 7.8 as is predicted for the global surface ocean by the year 2100, are dominated by exceptionally over-calcified morphotypes whose distal coccolith shield can be almost solid calcite. Shifts in morphotype composition of E. huxleyi populations correlate with changes in carbonate system parameters. We tested if these correlations indicate that the hyper-calcified morphotype is adapted to OA. In experimental exposures to present-day vs. future pCO2 (400 vs. 1200 µatm), the over-calcified morphotypes showed the same growth inhibition (−29.1±6.3 %) as moderately calcified morphotypes isolated from non-acidified water (−30.7±8.8 %). Under the high-CO2–low-pH condition, production rates of particulate organic carbon (POC) increased, while production rates of particulate inorganic carbon (PIC) were maintained or decreased slightly (but not significantly), leading to lowered PIC ∕ POC ratios in all strains. There were no consistent correlations of response intensity with strain origin. The high-CO2–low-pH condition affected coccolith morphology equally or more strongly in over-calcified strains compared to moderately calcified strains. High-CO2–low-pH conditions appear not to directly select for exceptionally over-calcified morphotypes over other morphotypes, but perhaps indirectly by ecologically correlated factors. More generally, these results suggest that oceanic planktonic microorganisms, despite their rapid turnover and large ... Article in Journal/Newspaper Ocean acidification ORA - Oxford University Research Archive Pacific Biogeosciences 15 5 1515 1534
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language English
description Marine multicellular organisms inhabiting waters with natural high fluctuations in pH appear more tolerant to acidification than conspecifics occurring in nearby stable waters, suggesting that environments of fluctuating pH hold genetic reservoirs for adaptation of key groups to ocean acidification (OA). The abundant and cosmopolitan calcifying phytoplankton Emiliania huxleyi exhibits a range of morphotypes with varying degrees of coccolith mineralization. We show that E. huxleyi populations in the naturally acidified upwelling waters of the eastern South Pacific, where pH drops below 7.8 as is predicted for the global surface ocean by the year 2100, are dominated by exceptionally over-calcified morphotypes whose distal coccolith shield can be almost solid calcite. Shifts in morphotype composition of E. huxleyi populations correlate with changes in carbonate system parameters. We tested if these correlations indicate that the hyper-calcified morphotype is adapted to OA. In experimental exposures to present-day vs. future pCO2 (400 vs. 1200 µatm), the over-calcified morphotypes showed the same growth inhibition (−29.1±6.3 %) as moderately calcified morphotypes isolated from non-acidified water (−30.7±8.8 %). Under the high-CO2–low-pH condition, production rates of particulate organic carbon (POC) increased, while production rates of particulate inorganic carbon (PIC) were maintained or decreased slightly (but not significantly), leading to lowered PIC ∕ POC ratios in all strains. There were no consistent correlations of response intensity with strain origin. The high-CO2–low-pH condition affected coccolith morphology equally or more strongly in over-calcified strains compared to moderately calcified strains. High-CO2–low-pH conditions appear not to directly select for exceptionally over-calcified morphotypes over other morphotypes, but perhaps indirectly by ecologically correlated factors. More generally, these results suggest that oceanic planktonic microorganisms, despite their rapid turnover and large ...
format Article in Journal/Newspaper
author Von Dassow, P
Díaz-Rosas, F
Bendif, E
Gaitán-Espitia, J
Mella-Flores, D
Rokitta, S
John, U
Torres, R
spellingShingle Von Dassow, P
Díaz-Rosas, F
Bendif, E
Gaitán-Espitia, J
Mella-Flores, D
Rokitta, S
John, U
Torres, R
Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
author_facet Von Dassow, P
Díaz-Rosas, F
Bendif, E
Gaitán-Espitia, J
Mella-Flores, D
Rokitta, S
John, U
Torres, R
author_sort Von Dassow, P
title Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
title_short Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
title_full Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
title_fullStr Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
title_full_unstemmed Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification
title_sort over-calcified forms of the coccolithophore emiliania huxleyi in high-co2 waters are not preadapted to ocean acidification
publisher European Geosciences Union
publishDate 2020
url https://doi.org/10.5194/bg-15-1515-2018
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