Publication Date:
2024-04-11
Description:
Ecophysiological studies looking at the combined effects of ocean acidification (OA) and iron (Fe) availability on Southern Ocean (SO) phytoplankton are still limited. To gain a better mechanistic understanding of how the two ecologically important SO phytoplankton groups cope with OA and Fe limitation, we conducted laboratory incubation experiments on the Antarctic cryptophyte Geminigera cryophila and the diatom Pseudo‐nitzschia subcurvata. Geminigera cryophila (CCMP 2564) was isolated from the Southern Ocean and obtained from Matt Johnson's Laboratory of Protistan Ecology at the Woods Hole Oceanography Institute, United States. Pseudo-nitzschia subcurvata was isolated from the Southern Ocean by P. Assmy during Polarstern expedition ANT- XXI/4. Both species were grown at 2°C under different pCO2 (400 vs. 900 μatm) and Fe (0.6 vs. 1.2 nM) conditions. For P. subcurvata, an additional high pCO2 level was applied (1400 μatm). For both species, growth, photophysiology, cellular quotas of particulate organic carbon, trace metals and pigments were assessed. Our study reveals that Fe limitation was detrimental for the growth of G. cryophila and suppressed the positive OA effect. The diatom was efficient in coping with low Fe, but was stressed by OA while both factors together strongly impacted its growth. The distinct physiological response of both species to OA and Fe limitation explains their occurrence in the field. Based on our results, Fe availability is an important modulator of OA effects on SO phytoplankton, with different implications on the occurrence of cryptophytes and diatoms in the future.
Keywords:
Alloxanthin; Alloxanthin, standard deviation; Carbon, organic, particulate; Carbon, organic, particulate, standard deviation; Carbon/Nitrogen ratio; Carbon/Nitrogen ratio, standard deviation; Chlorophyll a; Chlorophyll a, standard deviation; Chlorophyll c2; Chlorophyll c2, standard deviation; Cobalt/Carbon ratio; Cobalt/Carbon ratio, standard deviation; Connectivity between photosystem II; Connectivity between photosystem II, standard deviation; Copper/Carbon ratio; Copper/Carbon ratio, standard deviation; cryptophytes; culture experiment; Diadinoxanthin; Diadinoxanthin, standard deviation; diatoms; Electron transport rate, absolute; Electron transport rate, absolute, standard deviation; Elemental analyzer, HEKAtechGmbH, Euro EA; Fluorometer, fast repetition rate; FRRF; Fucoxanthin; Fucoxanthin, standard deviation; Functional absorption cross sections of photosystem II reaction centers; Functional absorption cross sections of photosystem II reaction centers, standard deviation; Functional photosystem II reaction centers; Functional photosystem II reaction centers, standard deviation; Growth rate, standard deviation; Inductively coupled plasma mass spectrometer (ICP-MS), Attom, Nu Instruments; Iron, cellular quota; Iron, cellular quota, standard deviation; Iron/Carbon ratio; Iron/Carbon ratio, standard deviation; Iron limitation; Irradiance; Laboratory experiment; Light microscopy (Utermöhl 1958); Light saturation point; Light saturation point, standard deviation; Light use efficiency; Manganese/Carbon ratio; Manganese/Carbon ratio, standard deviation; Maximal electron transport rate, standard deviation; Maximum light utilization efficiency, standard deviation; Maximum photochemical quantum yield of photosystem II; Maximum photochemical quantum yield of photosystem II, recovery; Maximum photochemical quantum yield of photosystem II, recovery, standard deviation; Maximum photochemical quantum yield of photosystem II, standard deviation; Nitrogen, organic, particulate; Non photochemical quenching; Non photochemical quenching, standard deviation; Ocean acidification; Particulate organic carbon, production, standard deviation; Particulate organic nitrogen production, standard deviation; Phytoplankton growth rate; Production of particulate organic carbon; Registration number of species; Reverse phase HPLC (High Performance Liquid Chromatography); Southern Ocean; Species; Treatment: dissolved iron; Treatment: partial pressure of carbon dioxide; Type of study; Uniform resource locator/link to reference; Zinc/Carbon ratio; Zinc/Carbon ratio, standard deviation
Type:
Dataset
Format:
text/tab-separated-values, 3068 data points
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