scholarly journals Population-specific responses in physiological rates of <i>Emiliania huxleyi</i> to a broad CO<sub>2</sub> range

2018 ◽  
Vol 15 (12) ◽  
pp. 3691-3701 ◽  
Author(s):  
Yong Zhang ◽  
Lennart T. Bach ◽  
Kai T. Lohbeck ◽  
Kai G. Schulz ◽  
Luisa Listmann ◽  
...  
Keyword(s):  
Canary Islands ◽  
Environmental Variability ◽  
Incubation Temperature ◽  
North Atlantic Ocean ◽  
Physiological Responses ◽  
Maximum Growth ◽  
Emiliania Huxleyi ◽  
Production Rates ◽  
Co2 Partial Pressure ◽  
Norwegian Coast

Abstract. Although coccolithophore physiological responses to CO2-induced changes in seawater carbonate chemistry have been widely studied in the past, there is limited knowledge on the variability of physiological responses between populations from different areas. In the present study, we investigated the specific responses of growth, particulate organic (POC) and inorganic carbon (PIC) production rates of three populations of the coccolithophore Emiliania huxleyi from three regions in the North Atlantic Ocean (Azores: six strains, Canary Islands: five strains, and Norwegian coast near Bergen: six strains) to a CO2 partial pressure (pCO2) range from 120 to 2630 µatm. Physiological rates of each population and individual strain increased with rising pCO2 levels, reached a maximum and declined thereafter. Optimal pCO2 for growth, POC production rates, and tolerance to low pH (i.e., high proton concentration) was significantly higher in an E. huxleyi population isolated from the Norwegian coast than in those isolated near the Azores and Canary Islands. This may be due to the large environmental variability including large pCO2 and pH fluctuations in coastal waters off Bergen compared to the rather stable oceanic conditions at the other two sites. Maximum growth and POC production rates of the Azores and Bergen populations were similar and significantly higher than that of the Canary Islands population. This pattern could be driven by temperature–CO2 interactions where the chosen incubation temperature (16 ∘C) was slightly below what strains isolated near the Canary Islands normally experience. Our results indicate adaptation of E. huxleyi to their local environmental conditions and the existence of distinct E. huxleyi populations. Within each population, different growth, POC, and PIC production rates at different pCO2 levels indicated strain-specific phenotypic plasticity. Accounting for this variability is important to understand how or whether E. huxleyi might adapt to rising CO2 levels.

scholarly journals Population-specific responses in physiological rates of <i>Emiliania huxleyi</i> to a broad CO<sub>2</sub> range

2018 ◽  
Author(s):  
Yong Zhang ◽  
Lennart T. Bach ◽  
Kai T. Lohbeck ◽  
Kai G. Schulz ◽  
Luisa Listmann ◽  
...  
Keyword(s):  
Canary Islands ◽  
Incubation Temperature ◽  
North Atlantic Ocean ◽  
Physiological Responses ◽  
Maximum Growth ◽  
Emiliania Huxleyi ◽  
Carbonate Chemistry ◽  
Production Rates ◽  
Co2 Partial Pressure ◽  
The North

Abstract. Although coccolithophore physiological responses to CO2-induced changes in seawater carbonate chemistry have been widely studied in the past, there is limited knowledge on the variability of physiological responses between populations. In the present study, we investigated the population-specific responses of growth, particulate organic (POC) and inorganic carbon (PIC) production rates of 17 strains of the coccolithophore Emiliania huxleyi from three regions in the North Atlantic Ocean (Azores, Canary Islands, and Norwegian coast near Bergen) to a CO2 partial pressure (pCO2) range from 120 µatm to 2630 µatm. Physiological rates of each population and individual strain displayed the expected optimum curve responses to the pCO2 gradient. Optimal pCO2 for growth and POC production rates and tolerance to low pH (i.e. high proton concentration) was significantly higher in an E. huxleyi population isolated from a Norwegian fjord than in those isolated near the Azores and Canary Islands. This may be due to the large pCO2 and pH variability in coastal waters off Bergen compared to the rather stable oceanic conditions at the other two sites. Maximum growth and POC production rates of the Azores and Bergen populations were similar and significantly higher than of the Canary Islands population. One of the reasons may be that the chosen incubation temperature (16 °C) is slightly below what strains isolated near the Canary Islands normally experience. Our results indicate adaptation of E. huxleyi to their local environmental conditions. Within each population, different growth, POC and PIC production rates at different pCO2 levels indicated strain-specific phenotypic plasticity. The existence of distinct carbonate chemistry responses between and within populations will likely benefit E. huxleyi to acclimate to rising CO2 levels in the oceans.

scholarly journals Influence of changing carbonate chemistry on morphology and weight of coccoliths formed by <i>Emiliania huxleyi</i>

2012 ◽  
Vol 9 (8) ◽  
pp. 3449-3463 ◽  
Author(s):  
L. T. Bach ◽  
C. Bauke ◽  
K. J. S. Meier ◽  
U. Riebesell ◽  
K. G. Schulz
Keyword(s):  
Sediment Cores ◽  
Emiliania Huxleyi ◽  
Marine Phytoplankton ◽  
Carbonate Chemistry ◽  
Production Rates ◽  
Organic Part ◽  
Carbonate Ion ◽  
Seawater Carbonate Chemistry ◽  
Decreasing Ph ◽  
Carbon Dioxide Co2

Abstract. The coccolithophore Emiliania huxleyi is a marine phytoplankton species capable of forming small calcium carbonate scales (coccoliths) which cover the organic part of the cell. Calcification rates of E. huxleyi are known to be sensitive to changes in seawater carbonate chemistry. It has, however, not yet been clearly determined how these changes are reflected in size and weight of individual coccoliths and which specific parameter(s) of the carbonate system drive morphological modifications. Here, we compare data on coccolith size, weight, and malformation from a set of five experiments with a large diversity of carbonate chemistry conditions. This diversity allows distinguishing the influence of individual carbonate chemistry parameters such as carbon dioxide (CO2), bicarbonate (HCO3−), carbonate ion (CO32−), and protons (H+) on the measured parameters. Measurements of fine-scale morphological structures reveal an increase of coccolith malformation with decreasing pH suggesting that H+ is the major factor causing malformations. Coccolith distal shield area varies from about 5 to 11 μm2. Changes in size seem to be mainly induced by varying [HCO3−] and [H+] although influence of [CO32−] cannot be entirely ruled out. Changes in coccolith weight were proportional to changes in size. Increasing CaCO3 production rates are reflected in an increase in coccolith weight and an increase of the number of coccoliths formed per unit time. The combined investigation of morphological features and coccolith production rates presented in this study may help to interpret data derived from sediment cores, where coccolith morphology is used to reconstruct calcification rates in the water column.

scholarly journals Seasonal and Spatial Variability in the Biogenic Production and Consumption of Volatile Organic Compounds (VOCs) by Marine Plankton in the North Atlantic Ocean

2020 ◽  
Vol 7 ◽  
Author(s):  
Cleo L. Davie-Martin ◽  
Stephen J. Giovannoni ◽  
Michael J. Behrenfeld ◽  
William B. Penta ◽  
Kimberly H. Halsey
Keyword(s):  
Volatile Organic Compounds ◽  
Atlantic Ocean ◽  
Organic Compounds ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Production Rates ◽  
The North ◽  
Production And Consumption ◽  
Volatile Organic ◽  
The North Atlantic

Marine-derived volatile organic compounds (VOCs) influence global carbon cycling, atmospheric reactions, and climate. Yet, the biogenic production (sources) and consumption (sink) rates of marine VOCs are not well-constrained and are currently excluded from global chemical transport models. We directly measured the net biogenic production rates of seven VOCs (acetaldehyde, acetone, acetonitrile, dimethylsulfide, isoprene, methanethiol, and methanol) in surface seawater during four field campaigns in the North Atlantic Ocean that targeted different stages of the phytoplankton annual cycle. All of the VOCs exhibited strong seasonal trends, with generally positive rates during May (peak spring bloom) and lower, sometimes negative rates (net consumption), during November and/or March (the winter bloom minimum transition). Strong latitudinal gradients were identified for most VOCs during May and September, with greater production observed in the northern regions compared to the southern regions. These gradients reflect the interplay between high phytoplankton and bacterial productivity. During the bloom transition stages (March and September), acetaldehyde and acetone exhibited net production rates that bracketed zero, suggesting that biogenic production was either very low or indicative of a tightly coupled system with more complex underlying microbial VOC cycling. Our data provides the first direct evidence for widespread biogenic acetonitrile production and consumption in the surface ocean and the first net biogenic production rates for methanethiol in natural seawater.

Physiological responses of juvenile Chilean scallops (Argopecten purpuratus) to isolated and combined environmental drivers of coastal upwelling

2019 ◽  
Vol 76 (6) ◽  
pp. 1836-1849 ◽  
Author(s):  
Laura Ramajo ◽  
Carolina Fernández ◽  
Yolanda Núñez ◽  
Paz Caballero ◽  
Marco A Lardies ◽  
...  
Keyword(s):  
Coastal Upwelling ◽  
Environmental Variability ◽  
Physiological Responses ◽  
Environmental Drivers ◽  
Hypoxic Conditions ◽  
Argopecten Purpuratus ◽  
Physiological Adaptations ◽  
Metabolic Performance ◽  
Increasing Temperature ◽  
The Impact

Abstract Coastal biota is exposed to continuous environmental variability as a consequence of natural and anthropogenic processes. Responding to heterogeneous conditions requires the presence of physiological strategies to cope with the environment. Ecosystems influenced by upwelling endure naturally cold, acidic and hypoxic conditions, nevertheless they sustain major fisheries worldwide. This suggests that species inhabiting upwelling habitats possess physiological adaptations to handle high environmental variability. Here, we assessed the impact of the main upwelling drivers (temperature, pH and oxygen) in isolation and combined on eco-physiological responses of Chilean scallop Argopecten purpuratus. A. purpuratus responded to hypoxia by increasing their metabolic performance to maintain growth and calcification. Calcification was only affected by pH and increased under acidic conditions. Further, A. purpuratus juveniles prioritized calcification at the expense of growth under upwelling conditions. Increasing temperature had a significant impact by enhancing the physiological performance of A. purpuratus juveniles independently of oxygen and pH conditions, but this was associated with earlier and higher mortalities. Our results suggest that A. purpuratus is acclimated to short-term colder, acidic and hypoxic conditions, and provide important information of how this species responds to the heterogeneous environment of upwelling, which is significantly relevant in the climatic context of upwelling intensification.

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