scholarly journals Predicting potential impacts of ocean acidification on marine calcifiers from the Southern Ocean

2020 ◽  
Author(s):  
Blanca Figuerola ◽  
Alyce M. Hancock ◽  
Narissa Bax ◽  
Vonda Cummings ◽  
Rachel Downey ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Ocean Acidification ◽  
Industrial Revolution ◽  
Negative Impact ◽  
Meta Analysis ◽  
Mineralogical Composition ◽  
Critical Issue ◽  
Biological Traits ◽  
Negative Effects ◽  
Species Specific

AbstractUnderstanding the vulnerability of marine calcifiers to ocean acidification is a critical issue, especially in the Southern Ocean (SO), which is likely to be the one of the first, and most severely affected regions. Since the industrial revolution, ~30% of anthropogenic CO2 has been absorbed by the oceans. Seawater pH levels have already decreased by 0.1 and are predicted to decline by ~ 0.3 by the year 2100. This process, known as ocean acidification (OA), is shallowing the saturation horizon, which is the depth below which calcium carbonate (CaCO3) dissolves, likely increasing the vulnerability of many marine calcifiers to dissolution. The negative impact of OA may be seen first in species depositing more soluble CaCO3 mineral phases such as aragonite and high-Mg calcite (HMC). These negative effects may become even exacerbated by increasing sea temperatures. Here we combine a review and a quantitative meta-analysis to provide an overview of the current state of knowledge about skeletal mineralogy of major taxonomic groups of SO marine calcifiers and to make predictions about how OA might affect different taxa. We consider their geographic range, skeletal mineralogy, biological traits and potential strategies to overcome OA. The meta-analysis of studies investigating the effects of the OA on a range of biological responses such as shell state, development and growth rate shows response variation depending on mineralogical composition. Species-specific responses due to mineralogical composition suggest taxa with calcitic, aragonitic and HMC skeletons may be more vulnerable to the expected carbonate chemistry alterations, and low magnesium calcite (LMC) species may be mostly resilient. Environmental and biological control on the calcification process and/or Mg content in calcite, biological traits and physiological processes are also expected to influence species specific responses.

scholarly journals A Review and Meta-Analysis of Potential Impacts of Ocean Acidification on Marine Calcifiers From the Southern Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Blanca Figuerola ◽  
Alyce M. Hancock ◽  
Narissa Bax ◽  
Vonda J. Cummings ◽  
Rachel Downey ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Ocean Acidification ◽  
Industrial Revolution ◽  
Negative Impact ◽  
Meta Analysis ◽  
Mineralogical Composition ◽  
Critical Issue ◽  
Biological Traits ◽  
Response Variation ◽  
Species Specific

Understanding the vulnerability of marine calcifiers to ocean acidification is a critical issue, especially in the Southern Ocean (SO), which is likely to be the one of the first, and most severely affected regions. Since the industrial revolution, ~30% of anthropogenic CO2 has been absorbed by the global oceans. Average surface seawater pH levels have already decreased by 0.1 and are projected to decline by ~0.3 by the year 2100. This process, known as ocean acidification (OA), is shallowing the saturation horizon, which is the depth below which calcium carbonate (CaCO3) dissolves, likely increasing the vulnerability of many resident marine calcifiers to dissolution. The negative impact of OA may be seen first in species depositing more soluble CaCO3 mineral phases such as aragonite and high-Mg calcite (HMC). Ocean warming could further exacerbate the effects of OA in these particular species. Here we combine a review and a quantitative meta-analysis to provide an overview of the current state of knowledge about skeletal mineralogy of major taxonomic groups of SO marine calcifiers and to make projections about how OA might affect a broad range of SO taxa. We consider a species' geographic range, skeletal mineralogy, biological traits, and potential strategies to overcome OA. The meta-analysis of studies investigating the effects of the OA on a range of biological responses such as shell state, development and growth rate illustrates that the response variation is largely dependent on mineralogical composition. Species-specific responses due to mineralogical composition indicate that taxa with calcitic, aragonitic, and HMC skeletons, could be at greater risk to expected future carbonate chemistry alterations, and low-Mg calcite (LMC) species could be mostly resilient to these changes. Environmental and biological control on the calcification process and/or Mg content in calcite, biological traits, and physiological processes are also expected to influence species-specific responses.

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 Reviews and Syntheses: Responses of coccolithophores to ocean acidification: a meta-analysis

2015 ◽  
Vol 12 (6) ◽  
pp. 1671-1682 ◽  
Author(s):  
J. Meyer ◽  
U. Riebesell
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Meta Analysis ◽  
Physiological Responses ◽  
Total Alkalinity ◽  
Adaptive Responses ◽  
Negative Effects ◽  
Ecological Fitness ◽  
Negative Effect ◽  
Gephyrocapsa Oceanica

Abstract. Concerning their sensitivity to ocean acidification, coccolithophores, a group of calcifying single-celled phytoplankton, are one of the best-studied groups of marine organisms. However, in spite of the large number of studies investigating coccolithophore physiological responses to ocean acidification, uncertainties still remain due to variable and partly contradictory results. In the present study we have used all existing data in a meta-analysis to estimate the effect size of future pCO2 changes on the rates of calcification and photosynthesis and the ratio of particulate inorganic to organic carbon (PIC / POC) in different coccolithophore species. Our results indicate that ocean acidification has a negative effect on calcification and the cellular PIC / POC ratio in the two most abundant coccolithophore species: Emiliania huxleyi and Gephyrocapsa oceanica. In contrast, the more heavily calcified species Coccolithus braarudii did not show a distinct response when exposed to elevated pCO2/reduced pH. Photosynthesis in Gephyrocapsa oceanica was positively affected by high CO2, while no effect was observed for the other coccolithophore species. There was no indication that the method of carbonate chemistry manipulation was responsible for the inconsistent results regarding observed responses in calcification and the PIC / POC ratio. The perturbation method, however, appears to affect photosynthesis, as responses varied significantly between total alkalinity (TA) and dissolved inorganic carbon (DIC) manipulations. These results emphasize that coccolithophore species respond differently to ocean acidification, both in terms of calcification and photosynthesis. Where negative effects occur, they become evident at CO2 levels in the range projected for this century in the case of unabated CO2 emissions. As the data sets used in this meta-analysis do not account for adaptive responses, ecological fitness and ecosystem interactions, the question remains as to how these physiological responses play out in the natural environment.

scholarly journals Quality of Research Design Moderates Effects of Grade Retention on Achievement: A Meta-Analytic, Multilevel Analysis

2009 ◽  
Vol 31 (4) ◽  
pp. 480-499 ◽  
Author(s):  
Chiharu S. Allen ◽  
Qi Chen ◽  
Victor L. Willson ◽  
Jan N. Hughes
Keyword(s):  
Grade Retention ◽  
Negative Impact ◽  
Meta Analysis ◽  
Median Number ◽  
Effect Sizes ◽  
Future Research ◽  
Negative Effects ◽  
Design Quality ◽  
Individual Level

The present meta-analysis examines the effect of grade retention on academic outcomes and investigates systemic sources of variability in effect sizes. Using multilevel modeling (MLM), the authors investigate characteristics of 207 effect sizes across 22 studies published between 1990 and 2007 at two levels: the study (between) and individual (within) levels. Design quality is a study-level variable. Individual-level variables are median grade retained and median number of years postretention. Quality of design is associated with less negative effects. Years postretention is negatively associated with retention effects, and this effect is stronger for studies using grade comparisons versus age comparisons. The results challenge the widely held view that retention has a negative impact on achievement. Suggestions for future research are discussed.

scholarly journals Seven years of experimental warming and nutrient addition causes decline of bryophytes and lichens in alpine meadow and heath communities

2014 ◽  
Author(s):  
Juha M Alatalo ◽  
Annika K Jägerbrand ◽  
Ulf Molau
Keyword(s):  
Global Change ◽  
Alpine Meadow ◽  
Negative Impact ◽  
Nutrient Addition ◽  
Negative Effects ◽  
Change Models ◽  
Alpine Regions ◽  
Negative Effect ◽  
Heath Community ◽  
Species Specific

Global change is predicted to have large and rapid impact on polar and alpine regions. Bryophytes and lichens increase their importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning at higher latitudes/altitudes. Here we report from a seven year factorial experiment with nutrient addition and warming on the abundance of bryophytes and lichens in an alpine meadow and heath community. Treatments had significant negative effect on relative change of total abundance bryophytes and lichens, the largest decline to the nutrient addition and the combined nutrient addition and warming treatments, bryophytes decreasing most in the meadow, lichens most in the heath. Nutrient addition, and the combined nutrient addition and warming brought rapid decrease in both bryophytes and lichens, while warming had a delayed negative impact. Of sixteen species that were included the statistical analyses, we found significant negative effects on seven species. We show that impact of simulated global change on bryophytes and lichens differ in in time and magnitude among treatments and plant communities. Our results underscore the importance of longer-term studies to improve the quality of climate change models, as short-term studies are poor predictors of longer-term responses of bryophytes and lichens, similar to what have been shown for vascular plants. Species-specific responses may differ in time, and this will likely cause changes in the dominance structures of bryophytes and lichens over time.

scholarly journals Management and Prevention of Complications of Guided Bone Regeneration

2019 ◽  
Vol 24 (4) ◽  
pp. 65-67
Author(s):  
Cristian Alexandru Țânțar
Keyword(s):  
Postoperative Complications ◽  
Bone Regeneration ◽  
Bone Growth ◽  
Negative Impact ◽  
Meta Analysis ◽  
Guided Bone Regeneration ◽  
Point Of View ◽  
Negative Effects ◽  
Late Exposure ◽  
The Right

Abstract Guided bone regeneration using titanium-reinforced expanded teflon non-absorbable membranes (e-PTFE) has proven, through rigorous studies on many occasions, that it is a safe and predictable method to achieve bone growth at mandible and maxilla level, both vertically and horizontally. However, the technique itself is one that requires special operative skills and is not without postoperative complications. The purpose of this paper is to review most of these postoperative complications, their management and the key operative elements that help preventing them. Complications are presented both from the perspective of the meta-analysis performed from the present literature and from the point of view of the author’s personal experience, personal casuistry being presented. This paper will discuss all this starting with the complications without negative impact on the bone regeneration such as, late exposure of the membrane and ending with the most serious ones, such as the suppuration of the augmented anatomical regions. All of these can be avoided or minimized by using a correct operating technique. In addition, once installed, we can minimize the negative effects on bone regeneration by a proper management applied at the right time.

Using Collective Creativity and Industry 4.0 Technology to Reduce the Negative Impact of a Pandemic on Entrepreneurs

2021 ◽  
pp. 133-155
Author(s):  
Ziska Fields ◽  
Zainab Mahammad Abdullah ◽  
Aidah Nakayiwa Musisi ◽  
Nadine Kirsten Mitchley
Keyword(s):  
Industry 4.0 ◽  
Conceptual Knowledge ◽  
Industrial Revolution ◽  
Negative Impact ◽  
Primary Objective ◽  
Primary Study ◽  
Negative Effects ◽  
Collective Creativity ◽  
External Forces ◽  
The Relationship

Across many domains, research has shown that a gap in knowledge exists on exploring the relationship between concepts such as collective creativity combined with the fourth industrial revolution. Furthermore, limited conceptual knowledge of how they may aid entrepreneurs when faced with a crisis of disruption trade due to external forces such as a pandemic. The primary objective of this study is to explain how collective creativity and Industry 4.0 technology can be used to reduce the negative effects of COVID-19 on local entrepreneurial enterprises by developing a framework of preparedness. A qualitative study, based on one-on-one interviews pertaining to local entrepreneurs located in Gauteng, South Africa. The results of the primary study and conclusion are yet to be established.

scholarly journals Seven years of experimental warming and nutrient addition causes decline of bryophytes and lichens in alpine meadow and heath communities

2014 ◽  
Author(s):  
Juha M Alatalo ◽  
Annika K Jägerbrand ◽  
Ulf Molau
Keyword(s):  
Global Change ◽  
Alpine Meadow ◽  
Negative Impact ◽  
Nutrient Addition ◽  
Negative Effects ◽  
Change Models ◽  
Alpine Regions ◽  
Negative Effect ◽  
Heath Community ◽  
Species Specific

Global change is predicted to have large and rapid impact on polar and alpine regions. Bryophytes and lichens increase their importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning at higher latitudes/altitudes. Here we report from a seven year factorial experiment with nutrient addition and warming on the abundance of bryophytes and lichens in an alpine meadow and heath community. Treatments had significant negative effect on relative change of total abundance bryophytes and lichens, the largest decline to the nutrient addition and the combined nutrient addition and warming treatments, bryophytes decreasing most in the meadow, lichens most in the heath. Nutrient addition, and the combined nutrient addition and warming brought rapid decrease in both bryophytes and lichens, while warming had a delayed negative impact. Of sixteen species that were included the statistical analyses, we found significant negative effects on seven species. We show that impact of simulated global change on bryophytes and lichens differ in in time and magnitude among treatments and plant communities. Our results underscore the importance of longer-term studies to improve the quality of climate change models, as short-term studies are poor predictors of longer-term responses of bryophytes and lichens, similar to what have been shown for vascular plants. Species-specific responses may differ in time, and this will likely cause changes in the dominance structures of bryophytes and lichens over time.

scholarly journals Seven years of experimental warming and nutrient addition causes decline of bryophytes and lichens in alpine meadow and heath communities

2014 ◽  
Author(s):  
Juha M Alatalo ◽  
Annika K Jägerbrand ◽  
Ulf Molau
Keyword(s):  
Global Change ◽  
Alpine Meadow ◽  
Negative Impact ◽  
Nutrient Addition ◽  
Negative Effects ◽  
Change Models ◽  
Alpine Regions ◽  
Negative Effect ◽  
Heath Community ◽  
Species Specific

Global change is predicted to have large and rapid impact on polar and alpine regions. Bryophytes and lichens increase their importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning at higher latitudes/altitudes. Here we report from a seven year factorial experiment with nutrient addition and warming on the abundance of bryophytes and lichens in an alpine meadow and heath community. Treatments had significant negative effect on relative change of total abundance bryophytes and lichens, the largest decline to the nutrient addition and the combined nutrient addition and warming treatments, bryophytes decreasing most in the meadow, lichens most in the heath. Nutrient addition, and the combined nutrient addition and warming brought rapid decrease in both bryophytes and lichens, while warming had a delayed negative impact. Of sixteen species that were included the statistical analyses, we found significant negative effects on seven species. We show that impact of simulated global change on bryophytes and lichens differ in time and magnitude among treatments and plant communities. Our results point out the importance of longer-term studies to improve the quality of climate change models, as short-term studies are poor predictors of longer-term responses of bryophytes and lichens, similar to what have been shown for vascular plants. Species-specific responses may differ in time, and this will likely cause changes in the dominance structures of bryophytes and lichens over time.

scholarly journals Responses of coccolithophores to ocean acidification: a meta-analysis

2014 ◽  
Vol 11 (10) ◽  
pp. 14857-14887
Author(s):  
J. Meyer ◽  
U. Riebesell
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Meta Analysis ◽  
Physiological Responses ◽  
Total Alkalinity ◽  
Adaptive Responses ◽  
Negative Effects ◽  
Ecological Fitness ◽  
Negative Effect ◽  
Gephyrocapsa Oceanica

Abstract. Concerning their sensitivity to ocean acidification, coccolithophores, a group of calcifying single-celled phytoplankton, are one of the best-studied groups of marine organisms. However, in spite of the large number of studies investigating coccolithophore physiological responses to ocean acidification, uncertainties still remain due to variable and partly contradictory results. In the present study we have used all existing data in a meta-analysis to estimate the effect size of future pCO2 changes on the rates of calcification and photosynthesis and the ratio of particulate inorganic to organic carbon (PIC/POC) in different coccolithophore species. Our results indicate that ocean acidification has a negative effect on calcification and the cellular PIC/POC ratio in the most abundant coccolithophore species Emiliania huxleyi and Gephyrocapsa oceanica. In contrast the more heavily calcified species Coccolithus braarudii did not show a distinct response when exposed to elevated pCO2/reduced pH. Photosynthesis in Gephyrocapsa oceanica was positively affected by high CO2, while no effect was observed for the other coccolithophore species. There was no indication that the method of carbonate chemistry manipulation was responsible for the inconsistent results regarding observed responses in calcification and the PIC/POC ratio. The perturbation method, however, appears to affect photosynthesis, as responses varied significantly between total alkalinity (TA) and dissolved inorganic carbon (DIC) manipulations. These results emphasize that coccolithophore species respond differently to ocean acidification, both in terms of calcification and photosynthesis. Where negative effects occur, they become evident at CO2 levels in the range projected for this century in case of unabated CO2 emissions. As the data sets used in this meta-analysis do not account for adaptive responses and ecological fitness, the questions remains how these physiological responses play out in the natural environment.

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