scholarly journals Effect of elevated CO<sub>2</sub> on the dynamics of particle attached and free living bacterioplankton communities in an Arctic fjord

2012 ◽  
Vol 9 (8) ◽  
pp. 10725-10755 ◽  
Author(s):  
M. Sperling ◽  
J. Piontek ◽  
G. Gerdts ◽  
A. Wichels ◽  
H. Schunck ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Intergenic Spacer ◽  
Extracellular Enzyme ◽  
The Arctic ◽  
Organic Substrates ◽  
Viral Lysis ◽  
Free Living ◽  
High Co2 ◽  
Carbon Dioxide Co2

Abstract. The increase in atmospheric carbon dioxide (CO2) results in acidification of the oceans, expected to lead to the fastest drop in ocean pH in the last 300 million years, if anthropogenic emissions are continued at present rate. Due to higher solubility of gases in cold waters and increased exposure to the atmosphere by decreasing ice cover, the Arctic Ocean will be among the areas most strongly affected by ocean acidification. Yet, the response of the plankton community of high latitudes to ocean acidification has not been studied so far. This work is part of the Arctic campaign of the European Project on Ocean Acidification (EPOCA) in 2010, employing 9 in situ mesocosms of about 45 000 l each to simulate ocean acidification in Kongsfjorden, Svalbard (78°56.2' N 11°53.6' E). In the present study, we investigated effects of elevated CO2 on the composition and richness of particle attached (PA; >3 μm) and free living (FL; <3 μm >0.2 μm) bacterial communities by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms and the surrounding fjord, ranging from 185 to 1050 initial μatm pCO2. ARISA was able to resolve about 20–30 bacterial band-classes per sample and allowed for a detailed investigation of the explicit richness. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom (phase 3 of the experiment), number of ARISA-band classes in the PA-community were reduced at low and medium CO2 (∼180–600 μatm) by about 25%, while it was more or less stable at high CO2 (∼ 650–800 μatm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA-bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was enhanced in high CO2-treatments, suggesting a positive effect of community richness on this function and on carbon cycling by bacteria.

scholarly journals Effect of elevated CO<sub>2</sub> on the dynamics of particle-attached and free-living bacterioplankton communities in an Arctic fjord

2013 ◽  
Vol 10 (1) ◽  
pp. 181-191 ◽  
Author(s):  
M. Sperling ◽  
J. Piontek ◽  
G. Gerdts ◽  
A. Wichels ◽  
H. Schunck ◽  
...  
Keyword(s):  
Large Scale ◽  
Intergenic Spacer ◽  
Extracellular Enzyme ◽  
Organic Substrates ◽  
Viral Lysis ◽  
Free Living ◽  
High Co2 ◽  
Arctic Fjord ◽  
Positive Effect

Abstract. In the frame of the European Project on Ocean Acidification (EPOCA), the response of an Arctic pelagic community (<3 mm) to a gradient of seawater pCO2 was investigated. For this purpose 9 large-scale in situ mesocosms were deployed in Kongsfjorden, Svalbard (78°56.2´ N, 11°53.6´ E), in 2010. The present study investigates effects on the communities of particle-attached (PA; >3 μm) and free-living (FL; < 3 μm > 0.2 μm) bacteria by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms, ranging from 185 to 1050 μatm initial pCO2, and the surrounding fjord. ARISA was able to resolve, on average, 27 bacterial band classes per sample and allowed for a detailed investigation of the explicit richness and diversity. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom, numbers of ARISA band classes in the PA community were reduced at low and medium CO2 (~ 185–685 μatm) by about 25%, while they were more or less stable at high CO2 (~ 820–1050 μatm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was enhanced in high CO2 mesocosms, suggesting a positive effect of community richness on this function and on carbon cycling by bacteria.

scholarly journals Does ocean acidification induce an upward flux of marine aggregates?

2008 ◽  
Vol 5 (4) ◽  
pp. 1023-1031 ◽  
Author(s):  
X. Mari
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
New Caledonia ◽  
Seawater Acidification ◽  
Seawater Ph ◽  
Biogenic Carbon ◽  
Marine Aggregates ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Sedimentation Processes

Abstract. The absorption of anthropogenic atmospheric carbon dioxide (CO2) by the ocean provokes its acidification. This acidification may alter several oceanic processes, including the export of biogenic carbon from the upper layer of the ocean, hence providing a feedback on rising atmospheric carbon concentrations. The effect of seawater acidification on transparent exopolymeric particles (TEP) driven aggregation and sedimentation processes were investigated by studying the interactions between latex beads and TEP precursors collected in the lagoon of New Caledonia. A suspension of TEP and beads was prepared and the formation of mixed aggregates was monitored as a function of pH under increasing turbulence intensities. The pH was controlled by addition of sulfuric acid. Aggregation and sedimentation processes driven by TEP were drastically reduced when the pH of seawater decreases within the expected limits imposed by increased anthropogenic CO2 emissions. In addition to the diminution of TEP sticking properties, the diminution of seawater pH led to a significant increase of the TEP pool, most likely due to swollen structures. A diminution of seawater pH by 0.2 units or more led to a stop or a reversal of the downward flux of particles. If applicable to oceanic conditions, the sedimentation of marine aggregates may slow down or even stop as the pH decreases, and the vertical flux of organic carbon may reverse. This would enhance both rising atmospheric carbon and ocean acidification.

scholarly journals Particulate trace metal dynamics in response to increased CO<sub>2</sub> and iron availability in a coastal mesocosm experiment

2020 ◽  
Vol 17 (3) ◽  
pp. 757-770 ◽  
Author(s):  
M. Rosario Lorenzo ◽  
María Segovia ◽  
Jay T. Cullen ◽  
María T. Maldonado
Keyword(s):  
Trace Metal ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Mesocosm Experiment ◽  
Dissolved Metals ◽  
High Co2 ◽  
Molar Ratios ◽  
Desferrioxamine B ◽  
Theoretical Predictions ◽  
Biogenic Metals

Abstract. Rising concentrations of atmospheric carbon dioxide are causing ocean acidification and will influence marine processes and trace metal biogeochemistry. In June 2012, in the Raunefjord (Bergen, Norway), we performed a mesocosm experiment, comprised of a fully factorial design of ambient and elevated pCO2 and/or an addition of the siderophore desferrioxamine B (DFB). In addition, the macronutrient concentrations were manipulated to enhance a bloom of the coccolithophore Emiliania huxleyi. We report the changes in particulate trace metal concentrations during this experiment. Our results show that particulate Ti and Fe were dominated by lithogenic material, while particulate Cu, Co, Mn, Zn, Mo and Cd had a strong biogenic component. Furthermore, significant correlations were found between particulate concentrations of Cu, Co, Zn, Cd, Mn, Mo and P in seawater and phytoplankton biomass (µgC L−1), supporting a significant influence of the bloom in the distribution of these particulate elements. The concentrations of these biogenic metals in the E. huxleyi bloom were ranked as follows: Zn < Cu ≈ Mn < Mo < Co < Cd. Changes in CO2 affected total particulate concentrations and biogenic metal ratios (Me : P) for some metals, while the addition of DFB only significantly affected the concentrations of some particulate metals (mol L−1). Variations in CO2 had the most clear and significant effect on particulate Fe concentrations, decreasing its concentration under high CO2. Indeed, high CO2 and/or DFB promoted the dissolution of particulate Fe, and the presence of this siderophore helped in maintaining high dissolved Fe. This shift between particulate and dissolved Fe concentrations in the presence of DFB, promoted a massive bloom of E. huxleyi in the treatments with ambient CO2. Furthermore, high CO2 decreased the Me : P ratios of Co, Zn and Mn while increasing the Cu : P ratios. These findings support theoretical predictions that the molar ratios of metal to phosphorous (Me : P ratios) of metals whose seawater dissolved speciation is dominated by free ions (e.g., Co, Zn and Mn) will likely decrease or stay constant under ocean acidification. In contrast, high CO2 is predicted to shift the speciation of dissolved metals associated with carbonates such as Cu, increasing their bioavailability and resulting in higher Me : P ratios.

scholarly journals Assessing carbon dioxide removal through global and regional ocean alkalinization under high and low emission pathways

2018 ◽  
Vol 9 (2) ◽  
pp. 339-357 ◽  
Author(s):  
Andrew Lenton ◽  
Richard J. Matear ◽  
David P. Keller ◽  
Vivian Scott ◽  
Naomi E. Vaughan
Keyword(s):  
Carbon Dioxide ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Global Scale ◽  
Earth System ◽  
Saturation State ◽  
Surface Warming ◽  
Regional Responses ◽  
Carbon Dioxide Co2 ◽  
Atmospheric Co2 Concentrations

Abstract. Atmospheric carbon dioxide (CO2) levels continue to rise, increasing the risk of severe impacts on the Earth system, and on the ecosystem services that it provides. Artificial ocean alkalinization (AOA) is capable of reducing atmospheric CO2 concentrations and surface warming and addressing ocean acidification. Here, we simulate global and regional responses to alkalinity (ALK) addition (0.25 PmolALK yr−1) over the period 2020–2100 using the CSIRO-Mk3L-COAL Earth System Model, under high (Representative Concentration Pathway 8.5; RCP8.5) and low (RCP2.6) emissions. While regionally there are large changes in alkalinity associated with locations of AOA, globally we see only a very weak dependence on where and when AOA is applied. On a global scale, while we see that under RCP2.6 the carbon uptake associated with AOA is only ∼ 60 % of the total, under RCP8.5 the relative changes in temperature are larger, as are the changes in pH (140 %) and aragonite saturation state (170 %). The simulations reveal AOA is more effective under lower emissions, therefore the higher the emissions the more AOA is required to achieve the same reduction in global warming and ocean acidification. Finally, our simulated AOA for 2020–2100 in the RCP2.6 scenario is capable of offsetting warming and ameliorating ocean acidification increases at the global scale, but with highly variable regional responses.

scholarly journals Does ocean acidification induce an upward flux of marine aggregates?

2008 ◽  
Vol 5 (2) ◽  
pp. 1631-1654 ◽  
Author(s):  
X. Mari
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
New Caledonia ◽  
Seawater Acidification ◽  
Seawater Ph ◽  
Biogenic Carbon ◽  
Marine Aggregates ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Sedimentation Processes

Abstract. The adsorption of anthropogenic atmospheric carbon dioxide (CO2) by the ocean provokes its acidification. This acidification may alter several oceanic processes, including the export of biogenic carbon from the upper layer of the ocean, hence providing a feedback on rising atmospheric carbon concentrations. The effect of seawater acidification on transparent exopolymeric particles (TEP) driven aggregation and sedimentation processes were investigated by studying the interactions between latex beads and TEP precursors collected in the lagoon of New Caledonia. A suspension of TEP and beads was prepared and the formation of mixed aggregates was monitored as a function of pH under increasing turbulence intensities. The pH was controlled by addition of sulfuric acid. Aggregation and sedimentation processes driven by TEP were drastically reduced when the pH of seawater decreases within the expected limits imposed by increased anthropogenic CO2 emissions. In addition to the diminution of TEP sticking properties, the diminution of seawater pH led to a significant increase of the TEP pool, most likely due to swollen structures. A diminution of seawater pH by 0.2 units or more led to a stop or a reversal of the downward flux of particles. If applicable to oceanic conditions, the sedimentation of marine aggregates may slow down or even stop as the pH decreases, and the vertical flux of organic carbon may reverse. This would enhance both rising atmospheric carbon and ocean acidification.

scholarly journals Accurate measurements of atmospheric carbon dioxide and methane mole fractions at the Siberian coastal site Ambarchik

2019 ◽  
Vol 12 (11) ◽  
pp. 5717-5740
Author(s):  
Friedemann Reum ◽  
Mathias Göckede ◽  
Jost V. Lavric ◽  
Olaf Kolle ◽  
Sergey Zimov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Arctic Ocean ◽  
Atmospheric Carbon Dioxide ◽  
Monitoring Network ◽  
The Arctic ◽  
Data Quality Control ◽  
In Situ Data ◽  
The Arctic Ocean ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2

Abstract. Sparse data coverage in the Arctic hampers our understanding of its carbon cycle dynamics and our predictions of the fate of its vast carbon reservoirs in a changing climate. In this paper, we present accurate measurements of atmospheric carbon dioxide (CO2) and methane (CH4) dry air mole fractions at the new atmospheric carbon observation station Ambarchik, which closes a large gap in the atmospheric trace gas monitoring network in northeastern Siberia. The site, which has been operational since August 2014, is located near the delta of the Kolyma River at the coast of the Arctic Ocean. Data quality control of CO2 and CH4 measurements includes frequent calibrations traced to World Meteorological Organization (WMO) scales, employment of a novel water vapor correction, an algorithm to detect the influence of local polluters, and meteorological measurements that enable data selection. The available CO2 and CH4 record was characterized in comparison with in situ data from Barrow, Alaska. A footprint analysis reveals that the station is sensitive to signals from the East Siberian Sea, as well as the northeast Siberian tundra and taiga regions. This makes data from Ambarchik highly valuable for inverse modeling studies aimed at constraining carbon budgets within the pan-Arctic domain, as well as for regional studies focusing on Siberia and the adjacent shelf areas of the Arctic Ocean.

Productivity of mungbean (Vigna radiata) with elevated carbon dioxideat various phosphorus levels and cyanobacteria inoculation

2016 ◽  
Author(s):  
Sumit Kumar Dey ◽  
B. Chakrabarti ◽  
R Prasanna ◽  
S. D. Singh ◽  
T J Purakayastha ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Elevated Co2 ◽  
Atmospheric Carbon Dioxide ◽  
Growth And Yield ◽  
Yield Attributes ◽  
High Co2 ◽  
Leaf Chlorophyll ◽  
Free Air ◽  
Co2 Level ◽  
Carbon Dioxide Co2

Increase in the concentration of atmospheric carbon dioxide (CO2) has significant impact on crop growth and productivity. A study was undertaken during the kharif season to study the impacts of elevated CO2 and cyanobacterial inoculation on growth and yield of mungbean crop under different doses of P using Free Air Carbon dioxide Enrichment (FACE) facility. The crop was grown under two CO2 levels i.e., ambient (400 µmol mol-1) and elevated (550 ± 20 µmol mol-1), with five levels of P (0, 8, 12, 16 and 20 mg P kg-1 soil) and 2 levels of calothrix sp. (with and without cyanobacteria) inoculation. Elevated CO2 level increased seed yield by 35.0% and biomass yield by 31.3%. Leaf area, photosynthesis rate and leaf chlorophyll content significantly increased at high CO2 level. Yield attributes such as number of pods plant-1, number of seeds pod-1 and test weight also increased at high CO2 level. Application of P and cyanobacterial inoculation further increased growth and yield of the crop. The study showed that application of P as well as cyanobacteria could help in improving productivity of legumes under elevated CO2 condition.

scholarly journals The Exploitation of Local Vitis vinifera L. Biodiversity as a Valuable Tool to Cope with Climate Change Maintaining Berry Quality

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 71
Author(s):  
María Carmen Antolín ◽  
María Toledo ◽  
Inmaculada Pascual ◽  
Juan José Irigoyen ◽  
Nieves Goicoechea
Keyword(s):  
Climate Change ◽  
Fruit Quality ◽  
Atmospheric Carbon Dioxide ◽  
Antioxidant Properties ◽  
Co2 Concentration ◽  
Soluble Solids ◽  
Vitis Vinifera L ◽  
Grape Quality ◽  
Berry Quality ◽  
Carbon Dioxide Co2

(1) Background: The associated increase in global mean surface temperature together with raised atmospheric carbon dioxide (CO2) concentration is exerting a profound influence on grapevine development (phenology) and grape quality. The exploitation of the local genetic diversity based on the recovery of ancient varieties has been proposed as an interesting option to cope with climate change and maintaining grape quality. Therefore, this research aimed to characterize the potential fruit quality of genotypes from seven local old grapevine varieties grown under climate change conditions. (2) Methods: The study was carried out on fruit-bearing cuttings (one cluster per plant) that were grown in pots in temperature gradient greenhouses (TGG). Two treatments were applied from fruit set to maturity: (1) ambient CO2 (400 ppm) and temperature (T) (ACAT) and (2) elevated CO2 (700 ppm) and temperature (T + 4 °C) (ECET). (3) Results: Results showed that some of the old genotypes tested remained quite stable during the climate change conditions in terms of fruit quality (mainly, total soluble solids and phenolic content) and of must antioxidant properties. (4) Conclusion: This research underlines the usefulness of exploiting local grapevine diversity to cope with climate change successfully, although further studies under field conditions and with whole plants are needed before extrapolating the results to the vineyard.

scholarly journals Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO<sub>2</sub> tolerance in phytoplankton productivity

2018 ◽  
Vol 15 (1) ◽  
pp. 209-231 ◽  
Author(s):  
Stacy Deppeler ◽  
Katherina Petrou ◽  
Kai G. Schulz ◽  
Karen Westwood ◽  
Imojen Pearce ◽  
...  
Keyword(s):  
Organic Matter ◽  
Ocean Acidification ◽  
Primary Productivity ◽  
Phytoplankton Community ◽  
Bacterial Abundance ◽  
Critical Threshold ◽  
Bacterial Productivity ◽  
High Co2 ◽  
Chl A ◽  
Antarctic Marine

Abstract. High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO2 levels  ≥ 1140 µatm negatively affected photosynthetic performance and Chl a-normalised primary productivity (csGPP14C), causing significant reductions in gross primary production (GPP14C), Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO2 treatments  ≥ 953 µatm (days 3–5), yet gross bacterial production (GBP14C) remained unchanged and cell-specific bacterial productivity (csBP14C) was reduced. Towards the end of the experiment, GBP14C and csBP14C markedly increased across all treatments regardless of CO2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative effects on the Antarctic food web and the biological pump, resulting in negative feedbacks on anthropogenic CO2 uptake. Increases in bacterial abundance under high CO2 conditions may also increase the efficiency of the microbial loop, resulting in increased organic matter remineralisation and further declines in carbon sequestration.

scholarly journals Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities

2014 ◽  
Vol 281 (1775) ◽  
pp. 20132479 ◽  
Author(s):  
K. E. Fabricius ◽  
G. De'ath ◽  
S. Noonan ◽  
S. Uthicke
Keyword(s):  
Ocean Acidification ◽  
Habitat Complexity ◽  
Atmospheric Carbon Dioxide ◽  
Coral Cover ◽  
Ecological Effects ◽  
Macroinvertebrate Communities ◽  
Dead Coral ◽  
Marine Communities

The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO 2 ) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO 2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO 2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO 2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO 2 tolerances derived from laboratory experiments. High CO 2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs.

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