Diurnally fluctuating pCO2 enhances growth of a coastal strain of Emiliania huxleyi under future-projected ocean acidification conditions

2021 ◽  
Author(s):  
Futian Li ◽  
Jiekai Xu ◽  
John Beardall ◽  
Kunshan Gao
Keyword(s):  
Ocean Acidification ◽  
Photosynthetic Electron Transport ◽  
Emiliania Huxleyi ◽  
Elevated Pco2 ◽  
Global Changes ◽  
Negative Effects ◽  
Carbon Cycles ◽  
Pco2 Treatment ◽  
Specific Growth Rates ◽  
Diel Fluctuations

Abstract The carbonate chemistry in coastal waters is more variable compared with that of open oceans, both in magnitude and time scale of its fluctuations. However, knowledge of the responses of coastal phytoplankton to dynamic changes in pH/pCO2 has been scarcely documented. Hence, we investigated the physiological performance of a coastal isolate of the coccolithophore Emiliania huxleyi (PML B92/11) under fluctuating and stable pCO2 regimes (steady ambient pCO2, 400 μatm; steady elevated pCO2, 1200 μatm; diurnally fluctuating elevated pCO2, 600–1800 μatm). Elevated pCO2 inhibited the calcification rate in both the steady and fluctuating regimes. However, higher specific growth rates and lower ratios of calcification to photosynthesis were detected in the cells grown under diurnally fluctuating elevated pCO2 conditions. The fluctuating pCO2 regime alleviated the negative effects of elevated pCO2 on effective photochemical quantum yield and relative photosynthetic electron transport rate compared with the steady elevated pCO2 treatment. Our results suggest that growth of E. huxleyi could benefit from diel fluctuations of pH/pCO2 under future-projected ocean acidification, but its calcification was reduced by the fluctuation and the increased concentration of CO2, reflecting a necessity to consider the influences of dynamic pH fluctuations on coastal carbon cycles associated with ocean global changes.

Non-lethal effects of ocean acidification on two symbiont-bearing benthic foraminiferal species

2011 ◽  
Vol 8 (5) ◽  
pp. 9165-9200 ◽  
Author(s):  
A. McIntyre-Wressnig ◽  
J. M. Bernhard ◽  
D. C. McCorkle ◽  
P. Hallock
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Dissolved Inorganic Carbon ◽  
Energy Levels ◽  
Elevated Pco2 ◽  
Total Alkalinity ◽  
Pore Waters ◽  
Lethal Effects ◽  
Enhanced Dissolution ◽  
Pco2 Treatment

Abstract. We conducted experiments to assess the effect of elevated atmospheric carbon dioxide concentrations on survival, fitness, shell microfabric and growth of two species of symbiont-bearing coral-reef benthic foraminifera, using pCO2 Ievels similar to those likely to occur in shallow marine pore waters in the decades ahead. Foraminifera were cultured at constant temperature and controlled pCO2 (385 ppmv, 1000 ppmv, and 2000 ppmv) for six weeks, and total alkalinity and dissolved inorganic carbon were measured to characterize the carbonate chemistry of the incubations. Foraminiferal survival and cellular energy levels were assessed using Adenosine Triphosphate (ATP) analyses, and test microstructure and growth were evaluated using high resolution SEM and image analysis. Fitness and survival of Amphistegina (A.) gibbosa and Archaias (A.) angulatus were not directly affected by elevated pCO2 and the concomitant decrease in pH and calcite saturation states (Ωc values) of the seawater (pH and Ωc values of 8.12, 7.86, and 7.50, and 5.4, 3.4, and 1.5, for control, 1000 ppmv, and 2000 ppmv, respectively). In A. gibbosa, a species precipitating low-Mg calcite, test growth was not affected by elevated pCO2, but areas of dissolved calcium carbonate were observed even though Ωc was >1 in all treatments; the fraction of test area dissolved increased with decreasing Ωc. Similar dissolution was observed in offspring produced in the 2000 ppmv pCO2 treatments. In A. angulatus, whose tests are more-solubile high-Mg calcite, growth was greatly diminished in the 2000 ppmv pCO2 treatment compared to the control. These non-lethal effects of ocean acidification – reduced growth in A. angulatus, and enhanced dissolution in A. gibbosa – may reflect differences in test mineralogy for the two species; the long-term ecological consequences of these effects are not yet known.

scholarly journals Physiological and biochemical responses of <i>Emiliania huxleyi</i> to ocean acidification and warming are modulated by UV radiation

2017 ◽  
Author(s):  
Shanying Tong ◽  
David A. Hutchins ◽  
Kunshan Gao
Keyword(s):  
Ocean Acidification ◽  
Uv Radiation ◽  
Carbon Fixation ◽  
Co2 Concentration ◽  
Emiliania Huxleyi ◽  
Marine Phytoplankton ◽  
Negative Effects ◽  
Photosynthetic Carbon Fixation ◽  
Photosynthetic Carbon ◽  
Increasing Temperature

Abstract. Marine phytoplankton such as bloom-forming, calcite-producing coccolithophores, are naturally exposed to solar UV radiation (UVR, 280–400 nm) in the ocean's upper mixed layers. Nevertheless, effects of increasing CO2-induced ocean acidification and warming have rarely been investigated in the presence of UVR. We examined calcification and photosynthetic carbon fixation performance in the most cosmopolitan coccolithophorid, Emiliania huxleyi, grown under high (1000 μatm, HC; pHT: 7.70) and low (400 μatm, LC; pHT: 8.02) CO2 levels, at 15 °C (LT), 20 °C (MT) and 24 °C (HT) with or without UVR. The HC treatment didn't affect photosynthetic carbon fixation at 15 °C, but significantly enhanced it with increasing temperature. Exposure to UVR inhibited photosynthesis, with higher inhibition by UVA (320–395 nm) than UVB (295–320 nm), except in the HC and 24 °C-grown cells, in which UVB caused more inhibition than UVA. Reduced thickness of the coccolith layer in the HC-grown cells appeared to be responsible for the UV-induced inhibition, and an increased repair rate of UVA-derived damage in the HCHT-grown cells could be responsible for lowered UVA-induced inhibition. While calcification was reduced with the elevated CO2 concentration, exposure to UVB or UVA affected it differentially, with the former inhibiting and the latter enhancing it. UVA-induced stimulation of calcification was higher in the HC-grown cells at 15 and 20 °C, whereas at 24 °C, observed enhancement was not significant. The calcification to photosynthesis ratio (Cal / Pho ratio) was lower in the HC treatment, and increasing temperature also lowered the value. However, at 20 and 24 °C, exposures to UVR significantly increased the Cal / Pho ratio, especially in HC-grown cells, by up to 100 %. This implies that UVR can counteract the negative effects of the greenhouse treatment on the Cal / Pho ratio, and so may be a key stressor when considering the impacts of future greenhouse conditions on E. huxleyi.

scholarly journals Sensitivity towards elevated <i>p</i>CO<sub>2</sub> in great scallop (<i>Pecten maximus</i> Lamarck) embryos and fed larvae

2016 ◽  
Author(s):  
Sissel Andersen ◽  
Ellen S. Grefsrud ◽  
Torstein Harboe
Keyword(s):  
Ocean Acidification ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Negative Effects ◽  
Great Scallop ◽  
Scallop Larvae ◽  
Negative Effect ◽  
Seawater Carbonate Chemistry

Abstract. The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH-values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 μatm, corresponding to pHNBS of 7.94, 7.74 and 7.54, respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only two days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 μatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. Food availability may not decrease the sensitivity to elevated pCO2 in scallop larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, populations of scallops may be negatively affected by ocean acidification in the future.

scholarly journals Physiological and biochemical responses of <i>Emiliania huxleyi</i> to ocean acidification and warming are modulated by UV radiation

2019 ◽  
Vol 16 (2) ◽  
pp. 561-572 ◽  
Author(s):  
Shanying Tong ◽  
David A. Hutchins ◽  
Kunshan Gao
Keyword(s):  
Ocean Acidification ◽  
Carbon Fixation ◽  
Co2 Concentration ◽  
Emiliania Huxleyi ◽  
Marine Phytoplankton ◽  
Negative Effects ◽  
Solar Ultraviolet Radiation ◽  
Photosynthetic Carbon Fixation ◽  
Photosynthetic Carbon ◽  
Increasing Temperature

Abstract. Marine phytoplankton such as bloom-forming, calcite-producing coccolithophores, are naturally exposed to solar ultraviolet radiation (UVR, 280–400 nm) in the ocean's upper mixed layers. Nevertheless, the effects of increasing carbon dioxide (CO2)-induced ocean acidification and warming have rarely been investigated in the presence of UVR. We examined calcification and photosynthetic carbon fixation performance in the most cosmopolitan coccolithophorid, Emiliania huxleyi, grown under high (1000 µatm, HC; pHT: 7.70) and low (400 µatm, LC; pHT: 8.02) CO2 levels, at 15 ∘C, 20 ∘C and 24 ∘C with or without UVR. The HC treatment did not affect photosynthetic carbon fixation at 15 ∘C, but significantly enhanced it with increasing temperature. Exposure to UVR inhibited photosynthesis, with higher inhibition by UVA (320–395 nm) than UVB (295–320 nm), except in the HC and 24 ∘C-grown cells, in which UVB caused more inhibition than UVA. A reduced thickness of the coccolith layer in the HC-grown cells appeared to be responsible for the UV-induced inhibition, and an increased repair rate of UVA-derived damage in the HC–high-temperature grown cells could be responsible for lowered UVA-induced inhibition. While calcification was reduced with elevated CO2 concentration, exposure to UVB or UVA affected the process differentially, with the former inhibiting it and the latter enhancing it. UVA-induced stimulation of calcification was higher in the HC-grown cells at 15 and 20 ∘C, whereas at 24 ∘C observed enhancement was not significant. The calcification to photosynthesis ratio (Cal ∕ Pho ratio) was lower in the HC treatment, and increasing temperature also lowered the value. However, at 20 and 24 ∘C, exposure to UVR significantly increased the Cal ∕ Pho ratio, especially in HC-grown cells, by up to 100 %. This implies that UVR can counteract the negative effects of the “greenhouse” treatment on the Cal ∕ Pho ratio; hence, UVR may be a key stressor when considering the impacts of future greenhouse conditions on E. huxleyi.

Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples

2014 ◽  
Vol 94 ◽  
pp. 1-6 ◽  
Author(s):  
Aki Kato ◽  
Mana Hikami ◽  
Naoki H. Kumagai ◽  
Atsushi Suzuki ◽  
Yukihiro Nojiri ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Negative Effects

scholarly journals Supplementary material to "Overcalcified forms of the coccolithophore <i>Emiliania huxleyi</i> in high CO<sub>2</sub> waters are not pre-adapted to ocean acidification"

2017 ◽  
Author(s):  
Peter von Dassow ◽  
Francisco Díaz-Rosas ◽  
El Mahdi Bendif ◽  
Juan-Diego Gaitán-Espitia ◽  
Daniella Mella-Flores ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Emiliania Huxleyi ◽  
Supplementary Material

scholarly journals Variability in the organic ligands released by Emiliania huxleyi under simulated ocean acidification conditions

2017 ◽  
Vol 4 (6) ◽  
pp. 788-808 ◽  
Author(s):  
Guillermo Samperio-Ramos ◽  
◽  
J. Magdalena Santana-Casiano ◽  
Melchor González-Dávila ◽  
Sonia Ferreira ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Emiliania Huxleyi ◽  
Organic Ligands

scholarly journals Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

2021 ◽  
Vol 118 (3) ◽  
pp. e2004769118
Author(s):  
Elizabeth M. Bullard ◽  
Ivan Torres ◽  
Tianqi Ren ◽  
Olivia A. Graeve ◽  
Kaustuv Roy
Keyword(s):  
Ocean Acidification ◽  
Historical Data ◽  
Mineralogical Composition ◽  
Marine Species ◽  
Mytilus Californianus ◽  
Negative Effects ◽  
Saturation State ◽  
Long Term Changes ◽  
Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

scholarly journals A gender bias in the calcification response to ocean acidification

2011 ◽  
Vol 8 (4) ◽  
pp. 8485-8513 ◽  
Author(s):  
M. Holcomb ◽  
A. L. Cohen ◽  
D. C. McCorkle
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Egg Production ◽  
Elevated Pco2 ◽  
Future Research ◽  
Astrangia Poculata ◽  
Population Structures ◽  
Different Temperatures ◽  
Increased Sensitivity ◽  
Ambient Co2

Abstract. The effects of nutrients and pCO2 on zooxanthellate and azooxanthellate colonies of the temperate scleractinian coral Astrangia poculata (Ellis and Solander, 1786) were investigated at two different temperatures (16 °C and 24 °C). Corals exposed to elevated pCO2 tended to have lower relative calcification rates, as estimated from changes in buoyant weights. No nutrient effect was observed. At 16 °C, gamete release was not observed, and no gender differences in calcification rate were observed. However, corals grown at 24 °C spawned repeatedly and male and female corals exhibited two different growth rate patterns. Female corals grown at 24 °C and exposed to CO2 had calcification rates 39 % lower than females grown at ambient CO2, while males showed only a 5 % decline in calcification under elevated CO2. At 16 °C, female and male corals showed similar reductions in calcification rates in response to elevated CO2 (15 % and 19 % respectively). At 24 °C, corals spawned repeatedly, while no spawning was observed at 16 °C. The increased sensitivity of females to elevated pCO2 may reflect a greater investment of energy in reproduction (egg production) relative to males (sperm production). These results suggest that both gender and spawning are important factors in determining the sensitivity of corals to ocean acidification and their inclusion in future research may be critical to predicting how the population structures of marine calcifiers will change in response to ocean acidification.

scholarly journals Nitrogen enrichment offsets direct negative effects of ocean acidification on a reef-building crustose coralline alga

2018 ◽  
Vol 14 (7) ◽  
pp. 20180371 ◽  
Author(s):  
Maggie D. Johnson ◽  
Robert C. Carpenter
Keyword(s):  
Ocean Acidification ◽  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Crustose Coralline Alga ◽  
Nitrogen Enrichment ◽  
Coralline Alga ◽  
Ambient Conditions ◽  
Negative Effects ◽  
Near Shore ◽  
Near Future

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes . Projected near-future pCO 2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO 2 treatments, respectively. pCO 2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO 2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a , phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO 2 . These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems.

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