scholarly journals Lipid Remodeling Reveals the Adaptations of a Marine Diatom to Ocean Acidification

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Jin ◽  
Zhe Liang ◽  
Hua Lu ◽  
Jinmei Pan ◽  
Peiyuan Li ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Phaeodactylum Tricornutum ◽  
Adaptation Strategy ◽  
Trophic Levels ◽  
Marine Diatom ◽  
Short Term ◽  
Tightly Coupled ◽  
Marine Food ◽  
Lipid Metabolites

Ocean acidification is recognized as a major anthropogenic perturbation of the modern ocean. While extensive studies have been carried out to explore the short-term physiological responses of phytoplankton to ocean acidification, little is known about their lipidomic responses after a long-term ocean acidification adaptation. Here we perform the lipidomic analysis of a marine diatom Phaeodactylum tricornutum following long-term (∼400 days) selection to ocean acidification conditions. We identified a total of 476 lipid metabolites in long-term high CO2 (i.e., ocean acidification condition) and low CO2 (i.e., ambient condition) selected P. tricornutum cells. Our results further show that long-term high CO2 selection triggered substantial changes in lipid metabolites by down- and up-regulating 33 and 42 lipid metabolites. While monogalactosyldiacylglycerol (MGDG) was significantly down-regulated in the long-term high CO2 selected conditions, the majority (∼80%) of phosphatidylglycerol (PG) was up-regulated. The tightly coupled regulations (positively or negatively correlated) of significantly regulated lipid metabolites suggest that the lipid remodeling is an organismal adaptation strategy of marine diatoms to ongoing ocean acidification. Since the composition and content of lipids are crucial for marine food quality, and these changes can be transferred to high trophic levels, our results highlight the importance of determining the long-term adaptation of lipids in marine producers in predicting the ecological consequences of climate change.

scholarly journals Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions

2013 ◽  
Vol 368 (1627) ◽  
pp. 20130186 ◽  
Author(s):  
Jasmin A. Godbold ◽  
Martin Solan
Keyword(s):  
Seasonal Variation ◽  
Ocean Acidification ◽  
Environmental Conditions ◽  
Nutrient Release ◽  
Interactive Effects ◽  
Long Term Effects ◽  
Short Term ◽  
Climatic Forcing ◽  
Species Responses

Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete ( Alitta virens ) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing.

Coupling of Function, Metabolism, and Blood Flow in the Brain

Physiology ◽  
1987 ◽  
Vol 2 (6) ◽  
pp. 217-220
Author(s):  
W Kuschinsky
Keyword(s):  
Blood Flow ◽  
Functional Activity ◽  
Capillary Density ◽  
Dynamic Coupling ◽  
Short Term ◽  
Local Activity ◽  
Vasoactive Factors ◽  
Tightly Coupled ◽  
The Brain

Functional activity, metabolism, and blood flow in the brain, although locally heterogeneous, are tightly coupled. Blood flow is adjusted to local activity in two ways: 1) short-term, dynamic coupling mediated by local vasoactive factors that ensure second-to-second regulation;and 2) long-term, static coupling apparently mediated by changes in capillary density. Recognizing these two mechanisms permits one to distinguish apparent from real uncoupling.

scholarly journals Impact of high pCO2 and warmer temperatures on the process of silica biomineralization in the sponge Mycale grandis

2015 ◽  
Vol 73 (3) ◽  
pp. 704-714 ◽  
Author(s):  
Jan Vicente ◽  
Nyssa J. Silbiger ◽  
Billie A. Beckley ◽  
Charles W. Raczkowski ◽  
Russell T. Hill
Keyword(s):  
Surface Temperature ◽  
Ocean Acidification ◽  
Sea Surface Temperature ◽  
Dry Weight ◽  
Sea Surface ◽  
High Pco2 ◽  
Short Term ◽  
Uptake Rates ◽  
Siliceous Sponges

Abstract Siliceous sponges have survived pre-historical mass extinction events caused by ocean acidification and recent studies suggest that siliceous sponges will continue to resist predicted increases in ocean acidity. In this study, we monitored silica biomineralization in the Hawaiian sponge Mycale grandis under predicted pCO2 and sea surface temperature scenarios for 2100. Our goal was to determine if spicule biomineralization was enhanced or repressed by ocean acidification and thermal stress by monitoring silica uptake rates during short-term (48 h) experiments and comparing biomineralized tissue ratios before and after a long-term (26 d) experiment. In the short-term experiment, we found that silica uptake rates were not impacted by high pCO2 (1050 µatm), warmer temperatures (27°C), or combined high pCO2 with warmer temperature (1119 µatm; 27°C) treatments. The long-term exposure experiments revealed no effect on survival or growth rates of M. grandis to high pCO2 (1198 µatm), warmer temperatures (25.6°C), or combined high pCO2 with warmer temperature (1225 µatm, 25.7°C) treatments, indicating that M. grandis will continue to prosper under predicted increases in pCO2 and sea surface temperature. However, ash-free dry weight to dry weight ratios, subtylostyle lengths, and silicified weight to dry weight ratios decreased under conditions of high pCO2 and combined pCO2 warmer temperature treatments. Our results show that rising ocean acidity and temperature have marginal negative effects on spicule biomineralization and will not affect sponge survival rates of M. grandis.

scholarly journals Alaskan carbon-climate feedbacks will be weaker than inferred from short-term experiments

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas J. Bouskill ◽  
William J. Riley ◽  
Qing Zhu ◽  
Zelalem A. Mekonnen ◽  
Robert F. Grant
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Cycle ◽  
Field Experiments ◽  
Ecosystem Model ◽  
Climate Feedbacks ◽  
Short Term ◽  
Ecosystem Carbon ◽  
Tightly Coupled

AbstractClimate warming is occurring fastest at high latitudes. Based on short-term field experiments, this warming is projected to stimulate soil organic matter decomposition, and promote a positive feedback to climate change. We show here that the tightly coupled, nonlinear nature of high-latitude ecosystems implies that short-term (<10 year) warming experiments produce emergent ecosystem carbon stock temperature sensitivities inconsistent with emergent multi-decadal responses. We first demonstrate that a well-tested mechanistic ecosystem model accurately represents observed carbon cycle and active layer depth responses to short-term summer warming in four diverse Alaskan sites. We then show that short-term warming manipulations do not capture the non-linear, long-term dynamics of vegetation, and thereby soil organic matter, that occur in response to thermal, hydrological, and nutrient transformations belowground. Our results demonstrate significant spatial heterogeneity in multi-decadal Arctic carbon cycle trajectories and argue for more mechanistic models to improve predictive capabilities.

scholarly journals Increase in ocean acidity variability and extremes under increasing atmospheric CO<sub>2</sub>

2020 ◽  
Author(s):  
Friedrich A. Burger ◽  
Thomas L. Frölicher ◽  
Jasmin G. John
Keyword(s):  
Ocean Acidification ◽  
Extreme Events ◽  
Co2 Emission ◽  
Emission Scenario ◽  
Short Term ◽  
Saturation State ◽  
High Co2 ◽  
Ensemble Simulations ◽  
The Impact

Abstract. Ocean acidity extreme events are short-term periods of extremely high [H+] concentrations. The uptake of anthropogenic CO2 emissions by the ocean is expected to lead to more frequent and intense ocean acidity extreme events, not only due to mean ocean acidification, but also due to increases in ocean acidity variability. Here, we use daily output from ensemble simulations of a comprehensive Earth system model under a low and high CO2 emission scenario to isolate and quantify the impact of changes in variability on changes in ocean acidity extremes. We show that the number of days with extreme [H+] conditions for surface waters is projected to increase by a factor of 14 by the end of the 21st century under a high CO2 emission scenario relative to preindustrial levels. The duration of individual events is projected to triple, and the maximal intensity and the volume extent in the upper 200 m to quintuple. Similar changes are projected in the thermocline. At surface, the changes are mainly driven by increases in [H+] seasonality, whereas changes in interannual variability are also important in the thermocline. Increases in [H+] variability and extremes arise predominantly from increases in the sensitivity of [H+] to variations in its drivers. In contrast to [H+] extremes, the occurrence of short-term extremes in low aragonite saturation state due to changes in variability is projected to decrease. An increase in [H+] variability and an associated increase in extreme events superimposed onto the long-term ocean acidification trend will enhance the risk of severe and detrimental impacts on marine organisms, especially for those that are adapted to a more stable environment.

scholarly journals Long-term acclimation to elevated p CO 2 alters carbon metabolism and reduces growth in the Antarctic diatom Nitzschia lecointei

2015 ◽  
Vol 282 (1815) ◽  
pp. 20151513 ◽  
Author(s):  
Anders Torstensson ◽  
Mikael Hedblom ◽  
My Mattsdotter Björk ◽  
Melissa Chierici ◽  
Angela Wulff
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Ocean Acidification ◽  
Carbon Metabolism ◽  
Physiological Responses ◽  
Bacterial Productivity ◽  
Short Term ◽  
The Antarctic ◽  
Slow Growing

Increasing atmospheric CO 2 levels are driving changes in the seawater carbonate system, resulting in higher p CO 2 and reduced pH (ocean acidification). Many studies on marine organisms have focused on short-term physiological responses to increased p CO 2 , and few on slow-growing polar organisms with a relative low adaptation potential. In order to recognize the consequences of climate change in biological systems, acclimation and adaptation to new environments are crucial to address. In this study, physiological responses to long-term acclimation (194 days, approx. 60 asexual generations) of three p CO 2 levels (280, 390 and 960 µatm) were investigated in the psychrophilic sea ice diatom Nitzschia lecointei . After 147 days, a small reduction in growth was detected at 960 µatm p CO 2 . Previous short-term experiments have failed to detect altered growth in N. lecointei at high p CO 2 , which illustrates the importance of experimental duration in studies of climate change. In addition, carbon metabolism was significantly affected by the long-term treatments, resulting in higher cellular release of dissolved organic carbon (DOC). In turn, the release of labile organic carbon stimulated bacterial productivity in this system. We conclude that long-term acclimation to ocean acidification is important for N. lecointei and that carbon overconsumption and DOC exudation may increase in a high-CO 2 world.

scholarly journals Short- and long-term conditioning of a temperate marine diatom community to acidification and warming

2013 ◽  
Vol 368 (1627) ◽  
pp. 20120437 ◽  
Author(s):  
Avery O. Tatters ◽  
Michael Y. Roleda ◽  
Astrid Schnetzer ◽  
Feixue Fu ◽  
Catriona L. Hurd ◽  
...  
Keyword(s):  
Community Structure ◽  
Global Change ◽  
Interspecific Interactions ◽  
Interactive Effects ◽  
Marine Diatom ◽  
Diatom Community ◽  
Natural Community ◽  
Short Term ◽  
Natural Assemblage

Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated p CO 2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and p CO 2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into ‘artificial’ communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned ‘artificial’ community experiments was similar, despite differences such as the loss of two species in the latter. p CO 2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes.

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