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Shang Y, He J, Qiu J, Hu S, Wang X, Zhang T, Wang W, Yuan X, Xu J, Li F. The tolerance of two marine diatoms to diurnal pH fluctuation under dynamic light condition and ocean acidification scenario. MARINE ENVIRONMENTAL RESEARCH 2024; 196:106425. [PMID: 38442592 DOI: 10.1016/j.marenvres.2024.106425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/29/2024] [Accepted: 02/25/2024] [Indexed: 03/07/2024]
Abstract
Coastal waters undergo dynamic changes in seawater carbonate chemistry due to natural and anthropogenic factors. Despite this, our current understanding of how coastal phytoplankton respond to fluctuating pH is limited. In the present study, we investigated the physiological responses of two coastal diatoms Thalassiosira pseudonana and Thalassiosira weissflogii to seawater acidification and diurnally fluctuating pH under natural solar irradiance. Seawater acidification did not significantly impact the growth, maximum and effective quantum yield of PSII, and photosynthetic rates of the two species. However, it did increase the maximum relative electron transport rate of T. weissflogii by 11%. Overall, fluctuating pH had neutral or positive effects on both species. It enhanced the light-saturated photosynthetic rate of T. weissflogii by 20% compared to cells grown under seawater acidification condition. Results from the short-term pH exposure experiment revealed that the photosynthetic rates of both species remained unaffected by acute pH changes, indicating their tolerance to varying pH. Nevertheless, it is crucial to consider dynamic pH when predicting changes in primary production in coastal waters, given the interplay of various environmental drivers.
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Affiliation(s)
- Yu Shang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Jie He
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Jingmin Qiu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Siyu Hu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Xin Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Tianzhi Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Weili Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Xiaoyue Yuan
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Futian Li
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China; Marine Resources Development Institute of Jiangsu, Jiangsu Ocean University, Lianyungang, China.
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Helbling EW, Banaszak AT, Valiñas MS, Vizzo JI, Villafañe VE, Cabrerizo MJ. Browning, nutrient inputs, and fast vertical mixing from simulated extreme rainfall and wind stress alter estuarine phytoplankton productivity. THE NEW PHYTOLOGIST 2023; 238:1876-1888. [PMID: 36908076 DOI: 10.1111/nph.18874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 02/25/2023] [Indexed: 05/04/2023]
Abstract
Browning and nutrient inputs from extreme rainfall, together with increased vertical mixing due to strong winds, are more frequent in coastal ecosystems; however, their interactive effects on phytoplankton are poorly understood. We conducted experiments to quantify how browning, together with different mixing speeds (fluctuating radiation), and a nutrient pulse alter primary productivity and photosynthetic efficiency in estuarine phytoplankton communities. Phytoplankton communities (grazers excluded) were exposed simultaneously to these drivers, and key photosynthetic targets were quantified: oxygen production, electron transport rates (ETRs), and carbon fixation immediately following collection and after a 2-d acclimation/adaptation period. Increasing mixing speeds in a turbid water column (e.g. browning) significantly decreased ETRs and carbon fixation in the short term. Acclimation/adaptation to this condition for 2 d resulted in an increase in nanoplanktonic diatoms and a community that was photosynthetically more efficient; however, this did not revert the decreasing trend in carbon fixation with increased mixing speed. The observed interactive effects (resulting from extreme rainfall and strong winds) may have profound implications in the trophodynamics of highly productive system such as the Southwest Atlantic Ocean due to changes in the size structure of the community and reduced productivity.
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Affiliation(s)
- E Walter Helbling
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Anastazia T Banaszak
- Integrative Reef Conservation Research Laboratory, Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Prol. Av. Niños Héroes S/N, Puerto Morelos, CP 77580, Mexico
| | - Macarena S Valiñas
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Juan I Vizzo
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marco J Cabrerizo
- Departamento de Ecología y Biología Animal, Facultad de Ciencias del Mar, Universidad de Vigo, Campus Lagoas Marcosende, s/n, Vigo, 36310, Spain
- Centro de Investigación Mariña da Universidade de Vigo (CIM-UVigo), Illa de Toralla s/n, Vigo, 36331, Spain
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, Granada, 18071, Spain
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Biswas H. A story of resilience: Arctic diatom Chaetoceros gelidus exhibited high physiological plasticity to changing CO 2 and light levels. FRONTIERS IN PLANT SCIENCE 2022; 13:1028544. [PMID: 36438134 PMCID: PMC9692007 DOI: 10.3389/fpls.2022.1028544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Arctic phytoplankton are experiencing multifaceted stresses due to climate warming, ocean acidification, retreating sea ice, and associated changes in light availability, and that may have large ecological consequences. Multiple stressor studies on Arctic phytoplankton, particularly on the bloom-forming species, may help understand their fitness in response to future climate change, however, such studies are scarce. In the present study, a laboratory experiment was conducted on the bloom-forming Arctic diatom Chaetoceros gelidus (earlier C. socialis) under variable CO2 (240 and 900 µatm) and light (50 and 100 µmol photons m-2 s-1) levels. The growth response was documented using the pre-acclimatized culture at 2°C in a closed batch system over 12 days until the dissolved inorganic nitrogen was depleted. Particulate organic carbon and nitrogen (POC and PON), pigments, cell density, and the maximum quantum yield of photosystem II (Fv/Fm) were measured on day 4 (D4), 6 (D6), 10 (D10), and 12 (D12). The overall growth response suggested that C. gelidus maintained a steady-state carboxylation rate with subsequent conversion to macromolecules as reflected in the per-cell POC contents under variable CO2 and light levels. A substantial amount of POC buildup at the low CO2 level (comparable to the high CO2 treatment) indicated the possibility of existing carbon dioxide concentration mechanisms (CCMs) that needs further investigation. Pigment signatures revealed a high level of adaptability to variable irradiance in this species without any major CO2 effect. PON contents per cell increased initially but decreased irrespective of CO2 levels when nitrogen was limited (D6 onward) possibly to recycle intracellular nitrogen resources resulting in enhanced C: N ratios. On D12 the decreased dissolved organic nitrogen levels could be attributed to consumption under nitrogen starvation. Such physiological plasticity could make C. gelidus "ecologically resilient" in the future Arctic.
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Affiliation(s)
- Haimanti Biswas
- National Institute of Oceanography - CSIR (Council of Scientific and Industrial Research), Biological Oceanography Division, Goa, India
- Polar Biological Oceanography, Alfred Wegener Institute of Polar and Marine Research, Bremerhaven, Germany
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Ma J, Wang P, Hu B, Wang X, Qian J. Synergistic promoting effect of increasing aquatic ammonium and CO 2 on Microcystis aeruginosa. CHEMOSPHERE 2022; 301:134553. [PMID: 35405194 DOI: 10.1016/j.chemosphere.2022.134553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/13/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Owing to climate change and intensive agricultural development, freshwater bodies have been affected by increases in both CO2 levels and chemically-reduced forms of N. However, little is known about how these changes affect cyanobacterial growth and blooms. This study explored a range of light conditions (30, 80, 130, or 200 μmol photons/m2/s) wherein Microcystis aeruginosa, a widespread bloom-forming species, was exposed to different concentrations of CO2 (400 parts per million (ppm) and 1000 ppm) in a medium containing NH4+ or NO3-. The interactive effects of N sources and CO2 levels on the C/N metabolic balance and energy balance were examined to assess changes in the growth of M. aeruginosa. When the light intensity was 80 μmol photons/m2/s, elevated CO2 could reduce intracellular reactive oxygen species (ROS) in NH4+-grown M. aeruginosa. Meanwhile, cell density and chlorophyll a (Chl a) increased with increasing CO2 levels, and the increase in Chl a was significantly greater in NH4+-grown M. aeruginosa than in NO3--grown M. aeruginosa. Under light conditions of 200 μmol photons/m2/s, elevated CO2 concentration caused NO3--grown M. aeruginosa to be affected by a large amount of ROS, and the growth of NO3--grown M. aeruginosa was finally suppressed. However, NH4+-grown M. aeruginosa had a smaller amount of ROS and showed improved growth as CO2 was elevated. This difference can be attributed to the faster metabolic pathways in the NH4+ environment, which manifested in a lower accumulation of 2-oxoglutarate and fatty acids as CO2 was elevated. These findings suggest that the simultaneous increase in ammonium and CO2 in aquatic ecosystems confers cyanobacteria with greater advantages than the combination of nitrate and CO2, which may aggravate cyanobacterial blooms.
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Affiliation(s)
- Jingjie Ma
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Bin Hu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xun Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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5
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Zhu Y, Feng Y, Browning TJ, Wen Z, Hughes DJ, Hao Q, Zhang R, Meng Q, Wells ML, Jiang Z, Dissanayake PAKN, Priyadarshani WNC, Shou L, Zeng J, Chai F. Exploring Variability of Trichodesmium Photophysiology Using Multi-Excitation Wavelength Fast Repetition Rate Fluorometry. Front Microbiol 2022; 13:813573. [PMID: 35464918 PMCID: PMC9026164 DOI: 10.3389/fmicb.2022.813573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/11/2022] [Indexed: 11/20/2022] Open
Abstract
Fast repetition rate fluorometry (FRRf) allows for rapid non-destructive assessment of phytoplankton photophysiology in situ yet has rarely been applied to Trichodesmium. This gap reflects long-standing concerns that Trichodesmium (and other cyanobacteria) contain pigments that are less effective at absorbing blue light which is often used as the sole excitation source in FRR fluorometers-potentially leading to underestimation of key fluorescence parameters. In this study, we use a multi-excitation FRR fluorometer (equipped with blue, green, and orange LEDs) to investigate photophysiological variability in Trichodesmium assemblages from two sites. Using a multi-LED measurement protocol (447+519+634 nm combined), we assessed maximum photochemical efficiency (F v /F m ), functional absorption cross section of PSII (σ PSII ), and electron transport rates (ETRs) for Trichodesmium assemblages in both the Northwest Pacific (NWP) and North Indian Ocean in the vicinity of Sri Lanka (NIO-SL). Evaluating fluorometer performance, we showed that use of a multi-LED measuring protocol yields a significant increase of F v /F m for Trichodesmium compared to blue-only excitation. We found distinct photophysiological differences for Trichodesmium at both locations with higher average F v /F m as well as lower σ PSII and non-photochemical quenching (NPQ NSV ) observed in the NWP compared to the NIO-SL (Kruskal-Wallis t-test df = 1, p < 0.05). Fluorescence light response curves (FLCs) further revealed differences in ETR response with a lower initial slope (α ETR ) and higher maximum electron turnover rate ( E T R P S I I m a x ) observed for Trichodesmium in the NWP compared to the NIO-SL, translating to a higher averaged light saturation E K (= E T R P S I I m a x /α ETR ) for cells at this location. Spatial variations in physiological parameters were both observed between and within regions, likely linked to nutrient supply and physiological stress. Finally, we applied an algorithm to estimate primary productivity of Trichodesmium using FRRf-derived fluorescence parameters, yielding an estimated carbon-fixation rate ranging from 7.8 to 21.1 mgC mg Chl-a-1 h-1 across this dataset. Overall, our findings demonstrate that capacity of multi-excitation FRRf to advance the application of Chl-a fluorescence techniques in phytoplankton assemblages dominated by cyanobacteria and reveals novel insight into environmental regulation of photoacclimation in natural Trichodesmium populations.
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Affiliation(s)
- Yuanli Zhu
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Yuanyuan Feng
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Thomas J. Browning
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Zuozhu Wen
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - David J. Hughes
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Qiang Hao
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Ruifeng Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Qicheng Meng
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Mark L. Wells
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Darling Marine Center, University of Maine, Walpole, ME, United States
| | - Zhibing Jiang
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - P. A. K. N. Dissanayake
- Department of Oceanography and Marine Geology, Faculty of Fisheries and Marine Sciences and Technology, University of Ruhuna, Matara, Sri Lanka
| | - W. N. C. Priyadarshani
- National Institute of Oceanography and Marine Sciences, National Aquatic Resources Research and Development Agency, Colombo, Sri Lanka
| | - Lu Shou
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jiangning Zeng
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Fei Chai
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
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6
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Duncan RJ, Nielsen DA, Sheehan CE, Deppeler S, Hancock AM, Schulz KG, Davidson AT, Petrou K. Ocean acidification alters the nutritional value of Antarctic diatoms. THE NEW PHYTOLOGIST 2022; 233:1813-1827. [PMID: 34988987 DOI: 10.1111/nph.17868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 11/07/2021] [Indexed: 06/14/2023]
Abstract
Primary production in the Southern Ocean is dominated by diatom-rich phytoplankton assemblages, whose individual physiological characteristics and community composition are strongly shaped by the environment, yet knowledge on how diatoms allocate cellular energy in response to ocean acidification (OA) is limited. Understanding such changes in allocation is integral to determining the nutritional quality of diatoms and the subsequent impacts on the trophic transfer of energy and nutrients. Using synchrotron-based Fourier transform infrared microspectroscopy, we analysed the macromolecular content of selected individual diatom taxa from a natural Antarctic phytoplankton community exposed to a gradient of fCO2 levels (288-1263 µatm). Strong species-specific differences in macromolecular partitioning were observed under OA. Large taxa showed preferential energy allocation towards proteins, while smaller taxa increased both lipid and protein stores at high fCO2 . If these changes are representative of future Antarctic diatom physiology, we may expect a shift away from lipid-rich large diatoms towards a community dominated by smaller taxa, but with higher lipid and protein stores than their present-day contemporaries, a response that could have cascading effects on food web dynamics in the Antarctic marine ecosystem.
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Affiliation(s)
- Rebecca J Duncan
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Department of Arctic Biology, The University Centre in Svalbard, Longyearbyen, 9171, Norway
| | - Daniel A Nielsen
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Cristin E Sheehan
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Stacy Deppeler
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., 7001, Australia
- National Institute of Water and Atmospheric Research, Wellington, 6021, New Zealand
| | - Alyce M Hancock
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., 7001, Australia
- Antarctic Gateway Partnership, Battery Point, Tas., 7004, Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Tas., 7001, Australia
| | - Kai G Schulz
- Centre for Coastal Biogeochemistry, Southern Cross University, East Lismore, NSW, 2480, Australia
| | - Andrew T Davidson
- Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Tas., 7001, Australia
- Australian Antarctic Division, Department of the Environment and Energy, Hobart, Tas., 7050, Australia
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, 2007, Australia
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Enhancement of diatom growth and phytoplankton productivity with reduced O 2 availability is moderated by rising CO 2. Commun Biol 2022; 5:54. [PMID: 35031680 PMCID: PMC8760321 DOI: 10.1038/s42003-022-03006-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 12/23/2021] [Indexed: 11/09/2022] Open
Abstract
Many marine organisms are exposed to decreasing O2 levels due to warming-induced expansion of hypoxic zones and ocean deoxygenation (DeO2). Nevertheless, effects of DeO2 on phytoplankton have been neglected due to technical bottlenecks on examining O2 effects on O2-producing organisms. Here we show that lowered O2 levels increased primary productivity of a coastal phytoplankton assemblage, and enhanced photosynthesis and growth in the coastal diatom Thalassiosira weissflogii. Mechanistically, reduced O2 suppressed mitochondrial respiration and photorespiration of T. weissflogii, but increased the efficiency of their CO2 concentrating mechanisms (CCMs), effective quantum yield and improved light use efficiency, which was apparent under both ambient and elevated CO2 concentrations leading to ocean acidification (OA). While the elevated CO2 treatment partially counteracted the effect of low O2 in terms of CCMs activity, reduced levels of O2 still strongly enhanced phytoplankton primary productivity. This implies that decreased availability of O2 with progressive DeO2 could boost re-oxygenation by diatom-dominated phytoplankton communities, especially in hypoxic areas, with potentially profound consequences for marine ecosystem services in coastal and pelagic oceans. Sun et al. investigate the effects of current ambient and potential future oxygen levels on phytoplankton growth and photosynthesis with field observations and mesocosm and lab experiments. Their results demonstrate positive effects of low O2 on phytoplankton growth, photosynthesis, and inorganic carbon acquisition at current and future high levels of CO2.
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8
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Kazama T, Hayakawa K, Kuwahara VS, Shimotori K, Imai A, Komatsu K. Development of photosynthetic carbon fixation model using multi-excitation wavelength fast repetition rate fluorometry in Lake Biwa. PLoS One 2021; 16:e0238013. [PMID: 33529253 PMCID: PMC7853527 DOI: 10.1371/journal.pone.0238013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 01/19/2021] [Indexed: 12/04/2022] Open
Abstract
Direct measurements of gross primary productivity (GPP) in the water column are essential, but can be spatially and temporally restrictive. Fast repetition rate fluorometry (FRRf) is a bio-optical technique based on chlorophyll a (Chl-a) fluorescence that can estimate the electron transport rate (ETRPSII) at photosystem II (PSII) of phytoplankton in real time. However, the derivation of phytoplankton GPP in carbon units from ETRPSII remains challenging because the electron requirement for carbon fixation (Фe,C), which is mechanistically 4 mol e− mol C−1 or above, can vary depending on multiple factors. In addition, FRRf studies are limited in freshwater lakes where phosphorus limitation and cyanobacterial blooms are common. The goal of the present study is to construct a robust Фe,C model for freshwater ecosystems using simultaneous measurements of ETRPSII by FRRf with multi-excitation wavelengths coupled with a traditional carbon fixation rate by the 13C method. The study was conducted in oligotrophic and mesotrophic parts of Lake Biwa from July 2018 to May 2019. The combination of excitation light at 444, 512 and 633 nm correctly estimated ETRPSII of cyanobacteria. The apparent range of Фe,C in the phytoplankton community was 1.1–31.0 mol e− mol C−1 during the study period. A generalised linear model showed that the best fit including 12 physicochemical and biological factors explained 67% of the variance in Фe,C. Among all factors, water temperature was the most significant, while photosynthetically active radiation intensity was not. This study quantifies the in situ FRRf method in a freshwater ecosystem, discusses core issues in the methodology to calculate Фe,C, and assesses the applicability of the method for lake GPP prediction.
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Affiliation(s)
- Takehiro Kazama
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Shiga, Japan
- Center for Regional Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
- * E-mail:
| | | | - Victor S. Kuwahara
- Graduate School of Science & Engineering, Soka University, Hachioji, Tokyo, Japan
| | - Koichi Shimotori
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Shiga, Japan
- Center for Regional Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
| | - Akio Imai
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Shiga, Japan
| | - Kazuhiro Komatsu
- Center for Regional Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
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9
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Hughes DJ, Giannini FC, Ciotti AM, Doblin MA, Ralph PJ, Varkey D, Verma A, Suggett DJ. Taxonomic Variability in the Electron Requirement for Carbon Fixation Across Marine Phytoplankton. JOURNAL OF PHYCOLOGY 2021; 57:111-127. [PMID: 32885422 DOI: 10.1111/jpy.13068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
Fast Repetition Rate fluorometry (FRRf) has been increasingly used to measure marine primary productivity by oceanographers to understand how carbon (C) uptake patterns vary over space and time in the global ocean. As FRRf measures electron transport rates through photosystem II (ETRPSII ), a critical, but difficult to predict conversion factor termed the "electron requirement for carbon fixation" (Φe,C ) is needed to scale ETRPSII to C-fixation rates. Recent studies have generally focused on understanding environmental regulation of Φe,C , while taxonomic control has been explored by only a handful of laboratory studies encompassing a limited diversity of phytoplankton species. We therefore assessed Φe,C for a wide range of marine phytoplankton (n = 17 strains) spanning multiple taxonomic and size classes. Data mined from previous studies were further considered to determine whether Φe,C variability could be explained by taxonomy versus other phenotypic traits influencing growth and physiological performance (e.g., cell size). We found that Φe,C exhibited considerable variability (~4-10 mol e- · [mol C]-1 ) and was negatively correlated with growth rate (R2 = 0.7, P < 0.01). Diatoms exhibited a lower Φe,C compared to chlorophytes during steady-state, nutrient-replete growth. Inclusion of meta-analysis data did not find significant relationships between Φe,C and class, or growth rate, although confounding factors inherent to methodological inconsistencies between studies likely contributed to this. Knowledge of empirical relationships between Φe,C and growth rate coupled with recent improvements in quantifying phytoplankton growth rates in situ, facilitate up-scaling of FRRf campaigns to routinely derive Φe,C needed to assess ocean C-cycling.
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Affiliation(s)
- David J Hughes
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Fernanda C Giannini
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
- Laboratorio Aquarela, Centro de Biologia Marinha (CEBIMar/USP) - Universidade de Sao Paulo, Rodovia Manoel Hypolito Rego, km 131.5, Sao Sebastiao, SP, Brazil
| | - Aurea M Ciotti
- Laboratorio Aquarela, Centro de Biologia Marinha (CEBIMar/USP) - Universidade de Sao Paulo, Rodovia Manoel Hypolito Rego, km 131.5, Sao Sebastiao, SP, Brazil
| | - Martina A Doblin
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Deepa Varkey
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Arjun Verma
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, 2007, Australia
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Ma J, Wang P. Effects of rising atmospheric CO 2 levels on physiological response of cyanobacteria and cyanobacterial bloom development: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141889. [PMID: 32920383 DOI: 10.1016/j.scitotenv.2020.141889] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/15/2020] [Accepted: 08/20/2020] [Indexed: 05/19/2023]
Abstract
Increasing atmospheric CO2 concentration negatively impacts aquatic ecosystems and may exacerbate the problem of undesirable cyanobacterial bloom development in freshwater ecosystems. Elevated levels of atmospheric CO2 may increase the levels of dissolved CO2 in freshwater systems, via air-water exchanges, enhancing primary production in the water and catchments. Although high CO2 levels improve cyanobacterial growth and increase cyanobacterial biomass, the impacts on their internal physiological processes can be more complex. Here, we have reviewed previous studies to evaluate the physiological responses of cyanobacteria to high concentrations of CO2. In response to high CO2 concentrations, the pressures of inorganic carbon absorption are reduced, and carbon concentration mechanisms are downregulated, affecting the intracellular metabolic processes and competitiveness of the cyanobacteria. Nitrogen and phosphorus metabolism and light utilization are closely related to CO2 assimilation, and these processes are likely to be affected by resource and energy reallocation when CO2 levels are high. Additionally, the responses of diazotrophic and toxic cyanobacteria to elevated CO2 levels were specifically reviewed. The responses of diazotrophic cyanobacteria to elevated CO2 concentrations were found to be inconsistent, probably because of differences in other factors in experimental designs. Toxic cyanobacteria tended to be superior to non-toxic strains at low levels of CO2; however, the specific effects of microcystin on the regulation require further investigation. Furthermore, the effects of increasing CO2 levels on cyanobacterial competitiveness in phytoplankton communities and nutrient cycling in aquatic ecosystems were reviewed. High CO2 concentrations may make cyanobacteria less competitive relative to other algal taxa; however, due to the complexity of natural systems and the specificity of algal species, the dominant positions of the cyanobacteria do not seems to be changed. To better understand cyanobacterial responses to elevated CO2 levels and help control cyanobacterial bloom developments, this review has identified key areas for future research.
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Affiliation(s)
- Jingjie Ma
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
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11
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Qu L, Campbell DA, Gao K. Ocean acidification interacts with growth light to suppress CO 2 acquisition efficiency and enhance mitochondrial respiration in a coastal diatom. MARINE POLLUTION BULLETIN 2021; 163:112008. [PMID: 33461076 DOI: 10.1016/j.marpolbul.2021.112008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
Diatom responses to ocean acidification have been documented with variable and controversial results. We grew the coastal diatom Thalassiosira weissflogii under 410 (LC, pH 8.13) vs 1000 μatm (HC, pH 7.83) pCO2 and at different levels of light (80, 140, 220 μmol photons m-2 s-1), and found that light level alters physiological responses to OA. CO2 concentrating mechanisms (CCMs) were down-regulated in the HC-grown cells across all the light levels, as reflected by lowered activity of the periplasmic carbonic anhydrase and decreased photosynthetic affinity for CO2 or dissolved inorganic carbon. The specific growth rate was, however, enhanced significantly by 9.2% only at the limiting low light level. These results indicate that rather than CO2 "fertilization", the energy saved from down-regulation of CCMs promoted the growth rate of the diatom when light availability is low, in parallel with enhanced respiration under OA to cope with the acidic stress by providing extra energy.
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Affiliation(s)
- Liming Qu
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Douglas A Campbell
- Biology Department, Mount Allison University, Sackville, NB E4L 1G7, Canada
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
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12
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Seifert M, Rost B, Trimborn S, Hauck J. Meta-analysis of multiple driver effects on marine phytoplankton highlights modulating role of pCO 2. GLOBAL CHANGE BIOLOGY 2020; 26:6787-6804. [PMID: 32905664 DOI: 10.1111/gcb.15341] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Responses of marine primary production to a changing climate are determined by a concert of multiple environmental changes, for example in temperature, light, pCO2 , nutrients, and grazing. To make robust projections of future global marine primary production, it is crucial to understand multiple driver effects on phytoplankton. This meta-analysis quantifies individual and interactive effects of dual driver combinations on marine phytoplankton growth rates. Almost 50% of the single-species laboratory studies were excluded because central data and metadata (growth rates, carbonate system, experimental treatments) were insufficiently reported. The remaining data (42 studies) allowed for the analysis of interactions of pCO2 with temperature, light, and nutrients, respectively. Growth rates mostly respond non-additively, whereby the interaction with increased pCO2 profusely dampens growth-enhancing effects of high temperature and high light. Multiple and single driver effects on coccolithophores differ from other phytoplankton groups, especially in their high sensitivity to increasing pCO2 . Polar species decrease their growth rate in response to high pCO2 , while temperate and tropical species benefit under these conditions. Based on the observed interactions and projected changes, we anticipate primary productivity to: (a) first increase but eventually decrease in the Arctic Ocean once nutrient limitation outweighs the benefits of higher light availability; (b) decrease in the tropics and mid-latitudes due to intensifying nutrient limitation, possibly amplified by elevated pCO2 ; and (c) increase in the Southern Ocean in view of higher nutrient availability and synergistic interaction with increasing pCO2 . Growth-enhancing effect of high light and warming to coccolithophores, mainly Emiliania huxleyi, might increase their relative abundance as long as not offset by acidification. Dinoflagellates are expected to increase their relative abundance due to their positive growth response to increasing pCO2 and light levels. Our analysis reveals gaps in the knowledge on multiple driver responses and provides recommendations for future work on phytoplankton.
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Affiliation(s)
- Miriam Seifert
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Björn Rost
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
- Universität Bremen, Bremen, Germany
| | - Scarlett Trimborn
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
- Universität Bremen, Bremen, Germany
| | - Judith Hauck
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
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13
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Zhang D, Xu J, Bao M, Yan D, Beer S, Beardall J, Gao K. Elevated CO 2 concentration alleviates UVR-induced inhibition of photosynthetic light reactions and growth in an intertidal red macroalga. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 213:112074. [PMID: 33152637 DOI: 10.1016/j.jphotobiol.2020.112074] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/19/2020] [Accepted: 10/26/2020] [Indexed: 02/06/2023]
Abstract
The commercially important red macroalga Pyropia (formerly Porphyra) yezoensis is, in its natural intertidal environment, subjected to high levels of both photosynthetically active and ultraviolet radiation (PAR and UVR, respectively). In the present work, we investigated the effects of a plausibly increased global CO2 concentration on quantum yields of photosystems II (PSII) and I (PSI), as well as photosynthetic and growth rates of P. yezoensis grown under natural solar irradiance regimes with or without the presence of UV-A and/or UV-B. Our results showed that the high-CO2 treatment (~1000 μbar, which also caused a drop of 0.3 pH units in the seawater) significantly increased both CO2 assimilation rates (by 35%) and growth (by 18%), as compared with ambient air of ~400 μbar CO2. The inhibition of growth by UV-A (by 26%) was reduced to 15% by high-CO2 concentration, while the inhibition by UV-B remained at ~6% under both CO2 concentrations. Homologous results were also found for the maximal relative photosynthetic electron transport rates (rETRmax), the maximum quantum yield of PSII (Fv/Fm), as well as the midday decrease in effective quantum yield of PSII (YII) and concomitant increased non-photochemical quenching (NPQ). A two-way ANOVA analysis showed an interaction between CO2 concentration and irradiance quality, reflecting that UVR-induced inhibition of both growth and YII were alleviated under the high-CO2 treatment. Contrary to PSII, the effective quantum yield of PSI (YI) showed higher values under high-CO2 condition, and was not significantly affected by the presence of UVR, indicating that it was well protected from this radiation. Both the elevated CO2 concentration and presence of UVR significantly induced UV-absorbing compounds. These results suggest that future increasing CO2 conditions will be beneficial for photosynthesis and growth of P. yezoensis even if UVR should remain at high levels.
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Affiliation(s)
- Di Zhang
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen 361105, China
| | - Juntian Xu
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Menglin Bao
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Dong Yan
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen 361105, China
| | - Sven Beer
- Department of Plant Sciences and Food Security, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - John Beardall
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen 361105, China; School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen 361105, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
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14
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Wang P, Ma J, Wang X, Tan Q. Rising atmospheric CO 2 levels result in an earlier cyanobacterial bloom-maintenance phase with higher algal biomass. WATER RESEARCH 2020; 185:116267. [PMID: 32798892 DOI: 10.1016/j.watres.2020.116267] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/28/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
The effect of rising atmospheric CO2 on freshwater lakes is a subject of considerable debate. However, it is not clear how rising CO2 concentration affects cyanobacterial bloom development under potential nutrient limitation conditions and if CO2 should be taken into account in making nutrient reduction strategy. To fill the knowledge gaps, this study investigated the spatiotemporal variability in aquatic CO2 concentration (pCO2) from 2006 to 2016 in Lake Taihu, where cyanobacterial blooms often occurred from late spring to the early fall. Lake Taihu is an atmospheric CO2 source in May and November, with only 18% and 11% pCO2-undersaturated areas, respectively. During cyanobacterial bloom in August, 81% of the lake areas are pCO2-undersaturated, absorbing ~ 0.53 t C/h of atmospheric CO2. The results demonstrated that CO2 transfer across air-water interface was important in supporting cyanobacterial bloom development. Besides, Field investigation showed that the chlorophyll a level is significantly positively correlated with supersaturated pCO2 (>13.56 µmol/L) in May, but pCO2 decreases with high chlorophyll a levels in August, suggesting that cyanobacterial growth would be promoted by high pCO2 over a threshold. These observations suggested that the effect of rising atmospheric CO2 on freshwater lakes and cyanobacterial blooms should be paid attention to. Further, when the N- and P-levels are >0.3 mg/L and >0.02 mg/L, respectively, high-pCO2 conditions allow a more rapid growth rate of cyanobacteria via improved nutrient-use efficiency. Moreover, cyanobacteria afford maximum N- or P-use efficiency at lower N- or P-concentrations with high CO2 concentration. This improvement would result in an earlier bloom-maintenance phase and higher cyanobacterial biomass. In this case, nutrient reduction is more imperative under future high CO2 conditions.
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Affiliation(s)
- Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China, 210098,; College of Environment, Hohai University, Nanjing, China, 210098.
| | - Jingjie Ma
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China, 210098,; College of Environment, Hohai University, Nanjing, China, 210098
| | - Xun Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China, 210098,; College of Environment, Hohai University, Nanjing, China, 210098
| | - Qingqian Tan
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China, 210098,; College of Environment, Hohai University, Nanjing, China, 210098
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15
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Li W, Wang T, Campbell DA, Gao K. Ocean acidification interacts with variable light to decrease growth but increase particulate organic nitrogen production in a diatom. MARINE ENVIRONMENTAL RESEARCH 2020; 160:104965. [PMID: 32291249 DOI: 10.1016/j.marenvres.2020.104965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/06/2020] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
Phytoplankton in the upper oceans are exposed to changing light levels due to mixing, diurnal solar cycles and weather conditions. Consequently, effects of ocean acidification are superimposed upon responses to variable light levels. We therefore grew a model diatom Thalassiosira pseudonana under either constant or variable light but at the same daily photon dose, with current low (400 μatm, LC) and future high CO2 (1000 μatm, HC) treatments. Variable light, compared with the constant light regime, decreased the growth rate, Chl a, Chl c, and carotenoid contents under both LC and HC conditions. Cells grown under variable light appeared more tolerant of high light as indicated by higher maximum relative electron transport rate and saturation light. Light variation interacted with high CO2/lowered pH to decrease the carbon fixation rate, but increased particulate organic carbon (POC) and particularly nitrogen (PON) per cell, which drove a decrease in C/N ratio, reflecting changes in the efficiency of energy transfer from photo-chemistry to net biomass production. Our results imply that elevated pCO2 under varying light conditions can lead to less primary productivity but more PON per biomass of the diatom, which might improve the food quality of diatoms and thereby influence biogeochemical nitrogen cycles.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China; College of Life and Environmental Sciences, Huangshan University, Huangshan, 245041, China
| | - Tifeng Wang
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China
| | - Douglas A Campbell
- Biology Department, Mount Allison University, Sackville, NB, E4L 1G7, Canada
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China.
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16
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Wei Y, Chen Z, Guo C, Zhong Q, Wu C, Sun J. Physiological and Ecological Responses of Photosynthetic Processes to Oceanic Properties and Phytoplankton Communities in the Oligotrophic Western Pacific Ocean. Front Microbiol 2020; 11:1774. [PMID: 32849398 PMCID: PMC7417450 DOI: 10.3389/fmicb.2020.01774] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 07/06/2020] [Indexed: 01/25/2023] Open
Abstract
Understanding the dynamics of primary productivity in a rapidly changing marine environment requires mechanistic insight into the photosynthetic processes (light absorption characteristics and electron transport) in response to the variability of environmental conditions and algal species. Here, we examined the photosynthetic performance and related physiological and ecological responses to oceanic properties [temperature, salinity, light, size-fractionated chlorophyll a (Chl a) and nutrients] and phytoplankton communities in the oligotrophic Western Pacific Ocean (WPO). Our results revealed high variability in the maximum (Fv/Fm; 0.08–0.26) and effective (Fq′/Fm′; 0.02–0.22) photochemical efficiency, the efficiency of charge separation (Fq′/Fv′; 0.19–1.06), the photosynthetic electron transfer rates (ETRRCII; 0.02–5.89 mol e– mol RCII–1 s–1) and the maximum of primary production [PPmax; 0.04–8.59 mg C (mg chl a)–1 h–1]. All these photosynthetic characteristics showed a depth-specific dependency based on respective nonlinear regression models. On physiological scales, variability in light absorption parameters Fv/Fm and Fq′/Fm′ notably correlated with light availability and size-fractionated Chl a, while both ETRRCII and PPmax were correlated to temperature, light, and ambient nutrient concentration. Since the presence of nonphotochemical quenching (NPQNSV; 2.33–12.31) and increasing reductant are used for functions other than carbon fixation, we observed nonparallel changes in the ETRRCII and Fv/Fm, Fq′/Fm′, Fq′/Fv′. In addition, we found that the important biotic variables influencing Fv/Fm were diatoms (cells > 2 μm), picosized Prochlorococcus, and eukaryotes, but the PPmax was closely related to large cyanobacteria (cells > 2 μm), dinoflagellates, and picosized Synechococcus. The implication is that, on ecological scales, an interaction among temperature, light, and nutrient availability may be key in driving the dynamics of primary productivity in the WPO, while large cyanobacteria, dinoflagellates, and picosized Synechococcus may have a high contribution to the primary production. Overall, the photosynthetic processes are interactively affected by complex abiotic and biotic variables in marine ecosystems, rather than by a single variable.
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Affiliation(s)
- Yuqiu Wei
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Zhuo Chen
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Congcong Guo
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Qi Zhong
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Chao Wu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Jun Sun
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
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17
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Kvernvik AC, Rokitta SD, Leu E, Harms L, Gabrielsen TM, Rost B, Hoppe CJM. Higher sensitivity towards light stress and ocean acidification in an Arctic sea-ice-associated diatom compared to a pelagic diatom. THE NEW PHYTOLOGIST 2020; 226:1708-1724. [PMID: 32086953 DOI: 10.1111/nph.16501] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Thalassiosira hyalina and Nitzschia frigida are important members of Arctic pelagic and sympagic (sea-ice-associated) diatom communities. We investigated the effects of light stress (shift from 20 to 380 µmol photons m-2 s-1 , resembling upwelling or ice break-up) under contemporary and future pCO2 (400 vs 1000 µatm). The responses in growth, elemental composition, pigmentation and photophysiology were followed over 120 h and are discussed together with underlying gene expression patterns. Stress response and subsequent re-acclimation were efficiently facilitated by T. hyalina, which showed only moderate changes in photophysiology and elemental composition, and thrived under high light after 120 h. In N. frigida, photochemical damage and oxidative stress appeared to outweigh cellular defenses, causing dysfunctional photophysiology and reduced growth. pCO2 alone did not specifically influence gene expression, but amplified the transcriptomic reactions to light stress, indicating that pCO2 affects metabolic equilibria rather than sensitive genes. Large differences in acclimation capacities towards high light and high pCO2 between T. hyalina and N. frigida indicate species-specific mechanisms in coping with the two stressors, which may reflect their respective ecological niches. This could potentially alter the balance between sympagic and pelagic primary production in a future Arctic.
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Affiliation(s)
- Ane C Kvernvik
- The Department of Arctic Biology, Svalbard Science Centre, University Centre in Svalbard, PO Box 156, N-9171, Longyearbyen, Norway
| | - Sebastian D Rokitta
- Marine Biogeosciences, Alfred-Wegener-Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Eva Leu
- Arctic R&D, Akvaplan-Niva AS, CIENS, Gaustadalleen 21, 0349, Oslo, Norway
| | - Lars Harms
- Marine Biogeosciences, Alfred-Wegener-Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Tove M Gabrielsen
- The Department of Arctic Biology, Svalbard Science Centre, University Centre in Svalbard, PO Box 156, N-9171, Longyearbyen, Norway
- Faculty of Engineering and Science, University of Agder, PO Box 422, N-4604, Kristiansand, Norway
| | - Björn Rost
- Marine Biogeosciences, Alfred-Wegener-Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
- FB2, University of Bremen, Leobener Strasse, 28359, Bremen, Germany
| | - Clara J M Hoppe
- Marine Biogeosciences, Alfred-Wegener-Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
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18
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Wolf KKE, Romanelli E, Rost B, John U, Collins S, Weigand H, Hoppe CJM. Company matters: The presence of other genotypes alters traits and intraspecific selection in an Arctic diatom under climate change. GLOBAL CHANGE BIOLOGY 2019; 25:2869-2884. [PMID: 31058393 PMCID: PMC6852494 DOI: 10.1111/gcb.14675] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 05/11/2023]
Abstract
Arctic phytoplankton and their response to future conditions shape one of the most rapidly changing ecosystems on the planet. We tested how much the phenotypic responses of strains from the same Arctic diatom population diverge and whether the physiology and intraspecific composition of multistrain populations differs from expectations based on single strain traits. To this end, we conducted incubation experiments with the diatom Thalassiosira hyalina under present-day and future temperature and pCO2 treatments. Six fresh isolates from the same Svalbard population were incubated as mono- and multistrain cultures. For the first time, we were able to closely follow intraspecific selection within an artificial population using microsatellites and allele-specific quantitative PCR. Our results showed not only that there is substantial variation in how strains of the same species cope with the tested environments but also that changes in genotype composition, production rates, and cellular quotas in the multistrain cultures are not predictable from monoculture performance. Nevertheless, the physiological responses as well as strain composition of the artificial populations were highly reproducible within each environment. Interestingly, we only detected significant strain sorting in those populations exposed to the future treatment. This study illustrates that the genetic composition of populations can change on very short timescales through selection from the intraspecific standing stock, indicating the potential for rapid population level adaptation to climate change. We further show that individuals adjust their phenotype not only in response to their physicochemical but also to their biological surroundings. Such intraspecific interactions need to be understood in order to realistically predict ecosystem responses to global change.
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Affiliation(s)
- Klara K. E. Wolf
- Marine BiogeosciencesAlfred Wegener Institut – Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
| | - Elisa Romanelli
- Marine BiogeosciencesAlfred Wegener Institut – Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia
| | - Björn Rost
- Marine BiogeosciencesAlfred Wegener Institut – Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
- University of BremenBremenGermany
| | - Uwe John
- Marine BiogeosciencesAlfred Wegener Institut – Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB)OldenburgGermany
| | - Sinead Collins
- Institute of Evolutionary Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Hannah Weigand
- Aquatic Ecosystem Research, Faculty of BiologyUniversity of Duisburg‐EssenEssenGermany
| | - Clara J. M. Hoppe
- Marine BiogeosciencesAlfred Wegener Institut – Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
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19
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Wei Y, Zhao X, Sun J, Liu H. Fast Repetition Rate Fluorometry (FRRF) Derived Phytoplankton Primary Productivity in the Bay of Bengal. Front Microbiol 2019; 10:1164. [PMID: 31244786 PMCID: PMC6544007 DOI: 10.3389/fmicb.2019.01164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 05/07/2019] [Indexed: 11/13/2022] Open
Abstract
The approach of fast repetition rate fluorometry (FRRF) requires a conversion factor (Φe : C/n PSII) to derive ecologically-relevant carbon uptake rates (PP z,t). However, the required Φe : C/n PSII is commonly measured by 14C assimilation and varies greatly across phytoplankton taxonomy and environmental conditions. Consequently, the use of FRRF to estimate gross primary productivity (GP z,t), alone or in combination with other approaches, has been restricted by both inherent conversion and procedural inconsistencies. Within this study, based on a hypothesis that the non-photochemical quenching (NPQNSV) can be used as a proxy for the variability and magnitude of Φe : C/n PSII, we thus proposed an independent field model coupling with the NPQNSV-based Φe : C/n PSII for FRRF-derived carbon, without the need for additional Φe : C/n PSII in the Bay of Bengal (BOB). Therewith, this robust algorithm was verified by the parallel measures of electron transport rates and 14C-uptake PP z,t. NPQNSV is theoretically caused by the effects of excess irradiance pressure, however, it showed a light and depth-independent response on large spatial scales of the BOB. Trends observed for the maximum quantum efficiency (Fv/Fm), the quantum efficiency of energy conversion ( F q ' / F m ' ) and the efficiency of charge separation ( F q ' / F v ' ) were similar and representative, which displayed a relative maximum at the subsurface and were collectively limited by excess irradiance. In particular, most observed values of Fv/Fm in the BOB were only about half of the values expected for nutrient replete phytoplankton. FRRF-based estimates of electron transport at PSII (ETRRCII) varied significantly, from 0.01 to 8.01 mol e- mol RCII-1 s-1, and showed profound responses to depth and irradiance across the BOB, but fitting with the logistic model. N, P, and irradiance are key environmental drivers in explaining the broad-scale variability of photosynthetic parameters. Furthermore, taxonomic shifts and physiological changes may be better predictors of photosynthetic parameters, and facilitate the selection of better adapted species to optimize photosynthetic efficiency under any particular set of ambient light condition.
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Affiliation(s)
- Yuqiu Wei
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Xiangwei Zhao
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Jun Sun
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Haijiao Liu
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
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20
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Wang T, Jin P, Wells ML, Trick CG, Gao K. Insensitivities of a subtropical productive coastal plankton community and trophic transfer to ocean acidification: Results from a microcosm study. MARINE POLLUTION BULLETIN 2019; 141:462-471. [PMID: 30955757 DOI: 10.1016/j.marpolbul.2019.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
Ocean acidification (OA) has potential to affect marine phytoplankton in ways that are partly understood, but there is less knowledge about how it may alter the coupling to secondary producers. We investigated the effects of OA on phytoplankton primary production, and its trophic transfer to zooplankton in a subtropical eutrophic water (Wuyuan Bay, China) under present day (400 μatm) and projected end-of-century (1000 μatm) pCO2 levels. Net primary production was unaffected, although OA did lead to small decreases in growth rates. OA had no measurable effect on micro-/mesozooplankton grazing rates. Elevated pCO2 had no effect on phytoplankton fatty acid (FA) concentrations during exponential phase, but saturated FAs increased relative to the control during declining phase. FA profiles of mesozooplankton were unaffected. Our findings show that short-term exposure of plankton communities in eutrophic subtropical waters to projected end-of-century OA conditions has little effect on primary productivity and trophic linkage to mesozooplankton.
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Affiliation(s)
- Tifeng Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Peng Jin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Mark L Wells
- School of Marine Sciences, University of Maine, Orono, ME 04469, USA
| | - Charles G Trick
- Department of Biology, Western University, London, Ontario, N6A 5B7, Canada
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China.
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21
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Kulk G, Buist A, van de Poll WH, Rozema PD, Buma AGJ. Size scaling of photophysiology and growth in four freshly isolated diatom species from Ryder Bay, western Antarctic peninsula. JOURNAL OF PHYCOLOGY 2019; 55:314-328. [PMID: 30449029 PMCID: PMC6590143 DOI: 10.1111/jpy.12813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
Diatoms are one of the dominant groups in phytoplankton communities of the western Antarctic Peninsula (WAP). Although generally well-studied, little is known about size dependent photophysiological responses in diatom bloom formation and succession. To increase this understanding, four Antarctic diatom species covering two orders of magnitude in cell size were isolated in northern Marguerite Bay (WAP). Fragilariopsis sp., Pseudo-nitzschia cf. subcurvata, Thalassiosira cf. antarctica, and Proboscia cf. alata were acclimated to three different irradiances after which photophysiology, electron transport, carbon fixation, and growth were assessed. The small species Fragilariopsis sp., Pseudo-nitzschia cf. subcurvata, and large species Proboscia cf. alata showed similar photoacclimation to higher irradiances with a decrease in cellular chlorophyll a and an increase in chlorophyll a specific absorption and xanthophyll cycle pigments and activity. In contrast, pigment concentrations and absorption remained unaffected by higher irradiances in the large species Thalassiosira cf. antarctica. Overall, the small species showed significantly higher growth rates compared to the large species, which was related to relatively high light harvesting capacity and electron transport rates in the smaller species. However, photophysiological responses related to photoinhibition and photoprotection and carbon fixation showed no relationship with cell size. This study supports the dominance of small diatoms at low irradiances during winter and early spring, but does not provide photophysiological evidence for the dominance of large diatoms during the phytoplankton bloom in the WAP. This suggests that other factors such as grazing and nutrient availability are likely to play a major role in diatom bloom formation.
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Affiliation(s)
- Gemma Kulk
- Department of Ocean EcosystemsEnergy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Anton Buist
- Department of Ocean EcosystemsEnergy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Willem H. van de Poll
- Department of Ocean EcosystemsEnergy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Patrick D. Rozema
- Department of Ocean EcosystemsEnergy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Anita G. J. Buma
- Department of Ocean EcosystemsEnergy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
- Arctic CentreFaculty of ArtsUniversity of GroningenAweg 309718 CWGroningenthe Netherlands
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22
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In-situ behavioural and physiological responses of Antarctic microphytobenthos to ocean acidification. Sci Rep 2019; 9:1890. [PMID: 30760730 PMCID: PMC6374400 DOI: 10.1038/s41598-018-36233-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 11/06/2018] [Indexed: 02/07/2023] Open
Abstract
Ocean acidification (OA) is predicted to alter benthic marine community structure and function, however, there is a paucity of field experiments in benthic soft sediment communities and ecosystems. Benthic diatoms are important components of Antarctic coastal ecosystems, however very little is known of how they will respond to ocean acidification. Ocean acidification conditions were maintained by incremental computer controlled addition of high fCO2 seawater representing OA conditions predicted for the year 2100. Respiration chambers and PAM fluorescence techniques were used to investigate acute behavioural, photosynthetic and net production responses of benthic microalgae communities to OA in in-situ field experiments. We demonstrate how OA can modify behavioural ecology, which changes photo-physiology and net production of benthic microalgae. Ocean acidification treatments significantly altered behavioural ecology, which in turn altered photo-physiology. The ecological trends presented here have the potential to manifest into significant ecological change over longer time periods.
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23
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Beszteri S, Thoms S, Benes V, Harms L, Trimborn S. The Response of Three Southern Ocean Phytoplankton Species to Ocean Acidification and Light Availability: A Transcriptomic Study. Protist 2018; 169:958-975. [DOI: 10.1016/j.protis.2018.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/06/2018] [Accepted: 08/17/2018] [Indexed: 01/16/2023]
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24
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Hughes DJ, Campbell DA, Doblin MA, Kromkamp JC, Lawrenz E, Moore CM, Oxborough K, Prášil O, Ralph PJ, Alvarez MF, Suggett DJ. Roadmaps and Detours: Active Chlorophyll- a Assessments of Primary Productivity Across Marine and Freshwater Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12039-12054. [PMID: 30247887 DOI: 10.1021/acs.est.8b03488] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Assessing phytoplankton productivity over space and time remains a core goal for oceanographers and limnologists. Fast Repetition Rate fluorometry (FRRf) provides a potential means to realize this goal with unprecedented resolution and scale yet has not become the "go-to" method despite high expectations. A major obstacle is difficulty converting electron transfer rates to equivalent rates of C-fixation most relevant for studies of biogeochemical C-fluxes. Such difficulty stems from methodological inconsistencies and our limited understanding of how the electron requirement for C-fixation (Φe,C) is influenced by the environment and by differences in the composition and physiology of phytoplankton assemblages. We outline a "roadmap" for limiting methodological bias and to develop a more mechanistic understanding of the ecophysiology underlying Φe,C. We 1) re-evaluate core physiological processes governing how microalgae invest photosynthetic electron transport-derived energy and reductant into stored carbon versus alternative sinks. Then, we 2) outline steps to facilitate broader uptake and exploitation of FRRf, which could transform our knowledge of aquatic primary productivity. We argue it is time to 3) revise our historic methodological focus on carbon as the currency of choice, to 4) better appreciate that electron transport fundamentally drives ecosystem biogeochemistry, modulates cell-to-cell interactions, and ultimately modifies community biomass and structure.
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Affiliation(s)
- David J Hughes
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Douglas A Campbell
- Department of Biology , Mount Allison University , Sackville , New Brunswick E4L 1E4 , Canada
| | - Martina A Doblin
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Jacco C Kromkamp
- Department of Estuarine and Delta Systems , NIOZ Royal Netherlands Institute for Sea Research and Utrecht University , P.O. Box 140, 4401 NT Yerseke , The Netherlands
| | - Evelyn Lawrenz
- Centre Algatech , Institute of Microbiology, Czech Academy of Sciences , Třeboň 379 81 , Czech Republic
| | - C Mark Moore
- Ocean and Earth Science , University of Southampton, National Oceanography Centre, Southampton , European Way , Southampton SO14 3ZH , U.K
| | | | - Ondřej Prášil
- Centre Algatech , Institute of Microbiology, Czech Academy of Sciences , Třeboň 379 81 , Czech Republic
| | - Peter J Ralph
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Marco F Alvarez
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - David J Suggett
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
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25
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Heiden JP, Thoms S, Bischof K, Trimborn S, Raven J. Ocean acidification stimulates particulate organic carbon accumulation in two Antarctic diatom species under moderate and high natural solar radiation. JOURNAL OF PHYCOLOGY 2018; 54:505-517. [PMID: 29791031 PMCID: PMC6120492 DOI: 10.1111/jpy.12753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Impacts of rising atmospheric CO2 concentrations and increased daily irradiances from enhanced surface water stratification on phytoplankton physiology in the coastal Southern Ocean remain still unclear. Therefore, in the two Antarctic diatoms Fragilariopsis curta and Odontella weissflogii, the effects of moderate and high natural solar radiation combined with either ambient or future pCO2 on cellular particulate organic carbon (POC) contents and photophysiology were investigated. Results showed that increasing CO2 concentrations had greater impacts on diatom physiology than exposure to increasing solar radiation. Irrespective of the applied solar radiation regime, cellular POC quotas increased with future pCO2 in both diatoms. Lowered maximum quantum yields of photochemistry in PSII (Fv /Fm ) indicated a higher photosensitivity under these conditions, being counteracted by increased cellular concentrations of functional photosynthetic reaction centers. Overall, our results suggest that both bloom-forming Antarctic coastal diatoms might increase carbon contents under future pCO2 conditions despite reduced physiological fitness. This indicates a higher potential for primary productivity by the two diatom species with important implications for the CO2 sequestration potential of diatom communities in the future coastal Southern Ocean.
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Affiliation(s)
- Jasmin P. Heiden
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
| | - Silke Thoms
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227568BremerhavenGermany
| | - Kai Bischof
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
| | - Scarlett Trimborn
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
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26
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Moreno CM, Lin Y, Davies S, Monbureau E, Cassar N, Marchetti A. Examination of gene repertoires and physiological responses to iron and light limitation in Southern Ocean diatoms. Polar Biol 2017. [DOI: 10.1007/s00300-017-2228-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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27
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Specific eukaryotic plankton are good predictors of net community production in the Western Antarctic Peninsula. Sci Rep 2017; 7:14845. [PMID: 29093494 PMCID: PMC5665988 DOI: 10.1038/s41598-017-14109-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/03/2017] [Indexed: 11/08/2022] Open
Abstract
Despite our current realization of the tremendous diversity that exists in plankton communities, we have little understanding of how this biodiversity influences the biological carbon pump other than broad paradigms such as diatoms contributing disproportionally to carbon export. Here we combine high-resolution underway O2/Ar, which provides an estimate of net community production, with high-throughput 18 S ribosomal DNA sequencing to elucidate the relationship between eukaryotic plankton community structure and carbon export potential at the Western Antarctica Peninsula (WAP), a region which has experienced rapid warming and ecosystem changes. Our results show that in a diverse plankton system comprised of ~464 operational taxonomic units (OTUs) with at least 97% 18 S identity, as few as two or three key OTUs, i.e. large diatoms, Phaeocystis, and mixotrophic/phagotrophic dinoflagellates, can explain a large majority of the spatial variability in the carbon export potential (76-92%). Moreover, we find based on a community co-occurrence network analysis that ecosystems with lower export potential have more tightly coupled communities. Our results indicate that defining plankton communities at a deeper taxonomic resolution than by functional groups and accounting for the differences in size and coupling between groups can substantially improve organic carbon flux predictions.
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28
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Hoppe CJM, Schuback N, Semeniuk D, Giesbrecht K, Mol J, Thomas H, Maldonado MT, Rost B, Varela DE, Tortell PD. Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance. Polar Biol 2017; 41:399-413. [PMID: 31983801 PMCID: PMC6952045 DOI: 10.1007/s00300-017-2186-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 11/29/2022]
Abstract
The Arctic Ocean is a region particularly prone to ongoing ocean acidification (OA) and climate-driven changes. The influence of these changes on Arctic phytoplankton assemblages, however, remains poorly understood. In order to understand how OA and enhanced irradiances (e.g., resulting from sea–ice retreat) will alter the species composition, primary production, and eco-physiology of Arctic phytoplankton, we conducted an incubation experiment with an assemblage from Baffin Bay (71°N, 68°W) under different carbonate chemistry and irradiance regimes. Seawater was collected from just below the deep Chl a maximum, and the resident phytoplankton were exposed to 380 and 1000 µatm pCO2 at both 15 and 35% incident irradiance. On-deck incubations, in which temperatures were 6 °C above in situ conditions, were monitored for phytoplankton growth, biomass stoichiometry, net primary production, photo-physiology, and taxonomic composition. During the 8-day experiment, taxonomic diversity decreased and the diatom Chaetoceros socialis became increasingly dominant irrespective of light or CO2 levels. We found no statistically significant effects from either higher CO2 or light on physiological properties of phytoplankton during the experiment. We did, however, observe an initial 2-day stress response in all treatments, and slight photo-physiological responses to higher CO2 and light during the first five days of the incubation. Our results thus indicate high resistance of Arctic phytoplankton to OA and enhanced irradiance levels, challenging the commonly predicted stimulatory effects of enhanced CO2 and light availability for primary production.
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Affiliation(s)
- C J M Hoppe
- 1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada.,2Marine Biogeosciences, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - N Schuback
- 1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada.,3Department of Physics and Astronomy, Curtin University, Perth, WA Australia
| | - D Semeniuk
- 1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada
| | - K Giesbrecht
- 4School of Earth and Ocean Sciences, University of Victoria, Victoria, BC Canada
| | - J Mol
- 5Department of Oceanography, Dalhousie University, Halifax, NS Canada
| | - H Thomas
- 5Department of Oceanography, Dalhousie University, Halifax, NS Canada
| | - M T Maldonado
- 1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada
| | - B Rost
- 2Marine Biogeosciences, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - D E Varela
- 4School of Earth and Ocean Sciences, University of Victoria, Victoria, BC Canada.,6Department of Biology, University of Victoria, Victoria, BC Canada
| | - P D Tortell
- 1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada.,7Department of Botany, University of British Columbia, Victoria, BC Canada.,8Peter Wall Institute for Advanced Studies, University of British Columbia, Vancouver, Canada
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29
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Trimborn S, Thoms S, Brenneis T, Heiden JP, Beszteri S, Bischof K. Two Southern Ocean diatoms are more sensitive to ocean acidification and changes in irradiance than the prymnesiophyte Phaeocystis antarctica. PHYSIOLOGIA PLANTARUM 2017; 160:155-170. [PMID: 28019019 DOI: 10.1111/ppl.12539] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/24/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
To better understand the impact of ocean acidification (OA) and changes in light availability on Southern Ocean phytoplankton physiology, we investigated the effects of pCO2 (380 and 800 µatm) in combination with low and high irradiance (20 or 50 and 200 µmol photons m-2 s-1 ) on growth, particulate organic carbon (POC) fixation and photophysiology in the three ecologically relevant species Chaetoceros debilis, Fragilariopsis kerguelensis and Phaeocystis antarctica. Irrespective of the light scenario, neither growth nor POC per cell was stimulated by OA in any of the tested species and the two diatoms even displayed negative responses in growth (e.g. C. debilis) or POC content (e.g. F. kerguelensis) under OA in conjunction with high light. For both diatoms, also maximum quantum yields of photosystem II (Fv /Fm ) were decreased under these conditions, indicating lowered photochemical efficiencies. To counteract the negative effects by OA and high light, the two diatoms showed diverging photoacclimation strategies. While cellular chlorophyll a (Chl a) and fucoxanthin contents were enhanced in C. debilis to potentially maximize light absorption, F. kerguelensis exhibited reduced Chl a per cell, increased disconnection of antennae from photosystem II reaction centers and strongly lowered absolute electron transport rates (ETR). The decline in ETRs in F. kerguelensis might be explained in terms of different species-specific strategies for tuning the available flux of adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. Overall, our results revealed that P. antarctica was more tolerant to OA and changes in irradiance than the two diatoms, which may have important implications for biogeochemical cycling.
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Affiliation(s)
- Scarlett Trimborn
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Silke Thoms
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Tina Brenneis
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Jasmin P Heiden
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Sara Beszteri
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Kai Bischof
- Marine Botany, University of Bremen, Bremen, Germany
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30
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Eberlein T, Wohlrab S, Rost B, John U, Bach LT, Riebesell U, Van de Waal DB. Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community. PLoS One 2017; 12:e0172594. [PMID: 28273107 PMCID: PMC5342202 DOI: 10.1371/journal.pone.0172594] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 02/07/2017] [Indexed: 11/18/2022] Open
Abstract
We studied the effect of ocean acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar Fjord, Sweden. CO2 concentrations were enriched in five mesocosms to reach average CO2 partial pressures (pCO2) of 760 μatm. The remaining five mesocosms were used as control at ambient pCO2 of 380 μatm. Our paper is part of a PLOS collection on this long-term mesocosm experiment. Here, we here tested the effect of OA on total primary production (PPT) by performing 14C-based bottle incubations for 24 h. Furthermore, photoacclimation was assessed by conducting 14C-based photosynthesis-irradiance response (P/I) curves. Changes in chlorophyll a concentrations over time were reflected in the development of PPT, and showed higher phytoplankton biomass build-up under OA. We observed two subsequent phytoplankton blooms in all mesocosms, with peaks in PPT around day 33 and day 56. OA had no significant effect on PPT, except for a marginal increase during the second phytoplankton bloom when inorganic nutrients were already depleted. Maximum light use efficiencies and light saturation indices calculated from the P/I curves changed simultaneously in all mesocosms, and suggest that OA did not alter phytoplankton photoacclimation. Despite large variability in time-integrated productivity estimates among replicates, our overall results indicate that coastal phytoplankton communities can be affected by OA at certain times of the seasonal succession with potential consequences for ecosystem functioning.
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Affiliation(s)
- Tim Eberlein
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
- * E-mail:
| | - Sylke Wohlrab
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
| | - Björn Rost
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
| | - Uwe John
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity Oldenburg (HIFMB), Carl von Ossietzky Straße, Oldenburg Germany
| | - Lennart T. Bach
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, Kiel, Germany
| | - Ulf Riebesell
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, Kiel, Germany
| | - Dedmer B. Van de Waal
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
- Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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31
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Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice. Sci Rep 2017; 7:40850. [PMID: 28102329 PMCID: PMC5244362 DOI: 10.1038/srep40850] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/09/2016] [Indexed: 01/28/2023] Open
Abstract
The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m-2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.
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32
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Petrou K, Kranz SA, Trimborn S, Hassler CS, Ameijeiras SB, Sackett O, Ralph PJ, Davidson AT. Southern Ocean phytoplankton physiology in a changing climate. JOURNAL OF PLANT PHYSIOLOGY 2016; 203:135-150. [PMID: 27236210 DOI: 10.1016/j.jplph.2016.05.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 06/05/2023]
Abstract
The Southern Ocean (SO) is a major sink for anthropogenic atmospheric carbon dioxide (CO2), potentially harbouring even greater potential for additional sequestration of CO2 through enhanced phytoplankton productivity. In the SO, primary productivity is primarily driven by bottom up processes (physical and chemical conditions) which are spatially and temporally heterogeneous. Due to a paucity of trace metals (such as iron) and high variability in light, much of the SO is characterised by an ecological paradox of high macronutrient concentrations yet uncharacteristically low chlorophyll concentrations. It is expected that with increased anthropogenic CO2 emissions and the coincident warming, the major physical and chemical process that govern the SO will alter, influencing the biological capacity and functioning of the ecosystem. This review focuses on the SO primary producers and the bottom up processes that underpin their health and productivity. It looks at the major physico-chemical drivers of change in the SO, and based on current physiological knowledge, explores how these changes will likely manifest in phytoplankton, specifically, what are the physiological changes and floristic shifts that are likely to ensue and how this may translate into changes in the carbon sink capacity, net primary productivity and functionality of the SO.
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Affiliation(s)
- Katherina Petrou
- School of Life Sciences, University of Technology Sydney, 15 Broadway, Ultimo, New South Wales 2007, Australia.
| | - Sven A Kranz
- Florida State University, Department of Earth, Ocean and Atmospheric Sciences, Tallahassee, FL 32306, USA
| | - Scarlett Trimborn
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; University of Bremen, Leobener Straße NW2, 28359 Bremen, Germany
| | - Christel S Hassler
- University of Geneva, Earth and Environmental Sciences, Institut F.-A. Forel, Uni Vogt, 66 bvd Carl-Vogt, 1211 Geneva 4, Switzerland
| | - Sonia Blanco Ameijeiras
- University of Geneva, Earth and Environmental Sciences, Institut F.-A. Forel, Uni Vogt, 66 bvd Carl-Vogt, 1211 Geneva 4, Switzerland
| | - Olivia Sackett
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, 15 Broadway, Ultimo, New South Wales 2007, Australia
| | - Andrew T Davidson
- Department of the Environment, Australian Antarctic Division, 203 Channel Highway, Kingston, Tasmania 7050, Australia; Antarctic Climate and Ecosystem Cooperative Research Centre (ACECRC), University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
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Kottmeier DM, Rokitta SD, Rost B. Acidification, not carbonation, is the major regulator of carbon fluxes in the coccolithophore Emiliania huxleyi. THE NEW PHYTOLOGIST 2016; 211:126-37. [PMID: 26918275 PMCID: PMC5069628 DOI: 10.1111/nph.13885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/06/2016] [Indexed: 05/11/2023]
Abstract
A combined increase in seawater [CO2 ] and [H(+) ] was recently shown to induce a shift from photosynthetic HCO3 (-) to CO2 uptake in Emiliania huxleyi. This shift occurred within minutes, whereas acclimation to ocean acidification (OA) did not affect the carbon source. To identify the driver of this shift, we exposed low- and high-light acclimated E. huxleyi to a matrix of two levels of dissolved inorganic carbon (1400, 2800 μmol kg(-1) ) and pH (8.15, 7.85) and directly measured cellular O2 , CO2 and HCO3 (-) fluxes under these conditions. Exposure to increased [CO2 ] had little effect on the photosynthetic fluxes, whereas increased [H(+) ] led to a significant decline in HCO3 (-) uptake. Low-light acclimated cells overcompensated for the inhibition of HCO3 (-) uptake by increasing CO2 uptake. High-light acclimated cells, relying on higher proportions of HCO3 (-) uptake, could not increase CO2 uptake and photosynthetic O2 evolution consequently became carbon-limited. These regulations indicate that OA responses in photosynthesis are caused by [H(+) ] rather than by [CO2 ]. The impaired HCO3 (-) uptake also provides a mechanistic explanation for lowered calcification under OA. Moreover, it explains the OA-dependent decrease in photosynthesis observed in high-light grown phytoplankton.
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Affiliation(s)
- Dorothee M. Kottmeier
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
| | - Sebastian D. Rokitta
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
| | - Björn Rost
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
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