Regulations pertaining to carbon dioxide capture with offshore storage (CCS) require an understan... more Regulations pertaining to carbon dioxide capture with offshore storage (CCS) require an understanding of the potential localised environmental impacts and demonstrably suitable monitoring practices. This study uses a marine ecosystem model to examine a comprehensive range of hypothetical CO2 leakage scenarios, quantifying both impact and recovery time within the benthic system. Whilst significant mortalities and long recovery times were projected for the larger and longer term scenarios, shorter-term or low level exposures lead to reduced projected impacts. This suggests that efficient monitoring and leak mitigation strategies, coupled with appropriate selection of storage sites can effectively limit concerns regarding localised environmental impacts from CCS. The feedbacks and interactions between physiological and ecological responses simulated reveal that benthic responses to CO2 leakage could be complex. This type of modelling investigation can aid the understanding of impact po...
Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is ... more Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is a leading subject of current research. The effects of acidification on non-calcifying macroalgae are, however, still unclear. The current study reports two 1-month studies using two different macroalgae, the red alga Palmaria palmata (Rhodophyta) and the kelp Saccharina latissima (Phaeophyta), exposed to control (pHNBS = ∼8.04) and increased (pHNBS = ∼7.82) levels of CO2-induced seawater acidification. The impacts of both increased acidification and time of exposure on net primary production (NPP), respiration (R), dimethylsulphoniopropionate (DMSP) concentrations, and algal growth have been assessed. In P. palmata, although NPP significantly increased during the testing period, it significantly decreased with acidification, whereas R showed a significant decrease with acidification only. S. latissima significantly increased NPP with acidification but not with time, and significantly inc...
Increased atmospheric CO2 concentration is leading to changes in the carbonate chemistry and the ... more Increased atmospheric CO2 concentration is leading to changes in the carbonate chemistry and the temperature of the ocean. The impact of these processes on marine organisms will depend on their ability to cope with those changes, particularly the maintenance of calcium carbonate structures. Both a laboratory experiment (long-term exposure to decreased pH and increased temperature) and collections of individuals from natural environments characterized by low pH levels (individuals from intertidal pools and around a CO2 seep) were here coupled to comprehensively study the impact of near-future conditions of pH and temperature on the mechanical properties of the skeleton of the euechinoid sea urchin Paracentrotus lividus. To assess skeletal mechanical properties, we characterized the fracture force, Young's modulus, second moment of area, material nanohardness, and specific Young's modulus of sea urchin test plates. None of these parameters were significantly affected by low pH...
Understanding long-term, ecosystem-level impacts of climate change is challenging because experim... more Understanding long-term, ecosystem-level impacts of climate change is challenging because experimental research frequently focuses on short-term, individual-level impacts in isolation. We address this shortcoming first through an interdisciplinary ensemble of novel experimental techniques to investigate the impacts of 14-month exposure to ocean acidification and warming (OAW) on the physiology, activity, predatory behaviour and susceptibility to predation of an important marine gastropod (Nucella lapillus). We simultaneously estimated the potential impacts of these global drivers on N. lapillus population dynamics and dispersal parameters. We then used these data to parameterize a dynamic bioclimatic envelope model, to investigate the consequences of OAW on the distribution of the species in the wider NE Atlantic region by 2100. The model accounts also for changes in the distribution of resources, suitable habitat and environment simulated by finely resolved biogeochemical models, u...
The distribution patterns of many species in the intertidal zone are partly determined by their a... more The distribution patterns of many species in the intertidal zone are partly determined by their ability to survive and recover from tidal emersion. During emersion most crustaceans experience gill-collapse impairing gas-exchange. Such collapse generates a state of hypoxemia and a hypercapnia-induced respiratory acidosis, leading to hyperlactaemia and metabolic acidosis. However, how such physiological responses to emersion are modified by prior exposure to elevated CO2 and temperature combinations, indicative of future climate change scenarios, is not known. We therefore investigated key physiological responses of velvet swimming crabs, Necora puber, kept for 14 days at one of four pCO2/temperature treatments (400 μatm/10 °C, 1000 μatm/10 °C, 400 μatm/15 °C, 1000 μatm/15 °C), to experimental emersion and recovery. Pre-exposure to elevated pCO2 and temperature increased pre-emersion bicarbonate ion concentrations [HCO3-], increasing resistance to short periods of emersion (90 min). H...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2013
Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric c... more Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric carbon dioxide (CO 2 ) in seawater, is projected to cause significant changes to marine ecology and biogeochemistry. Potential impacts on the microbially driven cycling of nitrogen are of particular concern. Specifically, under seawater pH levels approximating future OA scenarios, rates of ammonia oxidation (the rate-limiting first step of the nitrification pathway) have been shown to dramatically decrease in seawater, but not in underlying sediments. However, no prior study has considered the interactive effects of microbial ammonia oxidation and macrofaunal bioturbation activity, which can enhance nitrogen transformation rates. Using experimental mesocosms, we investigated the responses to OA of ammonia oxidizing microorganisms inhabiting surface sediments and sediments within burrow walls of the mud shrimp Upogebia deltaura . Seawater was acidified to one of four target pH values (pH T...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2013
Climate change may cause ecosystems to become trophically restructured as a result of primary pro... more Climate change may cause ecosystems to become trophically restructured as a result of primary producers and consumers responding differently to increasing CO 2 and temperature. This study used an integrative approach using a controlled microcosm experiment to investigate the combined effects of CO 2 and temperature on key components of the intertidal system in the UK, biofilms and their consumers ( Littorina littorea ). In addition, to identify whether pre-exposure to experimental conditions can alter experimental outcomes we explicitly tested for differential effects on L. littorea pre-exposed to experimental conditions for two weeks and five months. In contrast to predictions based on metabolic theory, the combination of elevated temperature and CO 2 over a five-week period caused a decrease in the amount of primary productivity consumed by grazers, while the abundance of biofilms increased. However, long-term pre-exposure to experimental conditions (five months) altered this effe...
... This community-based mesocosm study supports previ-ous suggestions, based on observations of ... more ... This community-based mesocosm study supports previ-ous suggestions, based on observations of direct physiological impacts, that ocean acidification induced changes in marine biodiversity will be driven by differential vulnerability within and between different taxonomical ...
The purple-tipped sea urchin, Psammechinus miliaris, was exposed to artificially acidified seawat... more The purple-tipped sea urchin, Psammechinus miliaris, was exposed to artificially acidified seawater treatments (pH(w) 6.16, 6.63 or 7.44) over a period of 8 days. Urchin mortality of 100% was observed at pH(w) 6.16 after 7 days and coincided with a pronounced hypercapnia in the coelomic fluid producing an irrecoverable acidosis. Coelomic fluid acid-base measures showed that an accumulation of CO(2) and a significant reduction in pH occurred in all treatments compared with controls. Bicarbonate buffering was employed in each case, reducing the resultant acidosis, but compensation was incomplete even under moderate environmental hypercapnia. Significant test dissolution was inferred from observable increases in the Mg(2+) concentration of the coelomic fluid under all pH treatments. We show that a chronic reduction of surface water pH to below 7.5 would be severely detrimental to the acid-base balance of this predominantly intertidal species; despite its ability to tolerate fluctuations in pCO(2) and pH in the rock pool environment. The absence of respiratory pigment (or any substantial protein in the coelomic fluid), a poor capacity for ionic regulation and dependency on a magnesium calcite test, make echinoids particularly vulnerable to anthropogenic acidification. Geological sequestration leaks may result in dramatic localised pH reductions, e.g. pH 5.8. P. miliaris is intolerant of pH 6.16 seawater and significant mortality is seen at pH 6.63.
Abstract The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on t... more Abstract The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on the global sulphur cycle and may influence local climate through the formation of dimethylsulphide (DMS). However, the effect of global change on DMSP/DMS (DMS (P)) production by algae is not well understood. This study examined the effect of low pH on DMS (P) production and epithelial cell morphology of the free-living red coralline alga Lithothamnion glaciale. Three pH treatments were used in the 80-day experiment:(1) ...
Regulations pertaining to carbon dioxide capture with offshore storage (CCS) require an understan... more Regulations pertaining to carbon dioxide capture with offshore storage (CCS) require an understanding of the potential localised environmental impacts and demonstrably suitable monitoring practices. This study uses a marine ecosystem model to examine a comprehensive range of hypothetical CO2 leakage scenarios, quantifying both impact and recovery time within the benthic system. Whilst significant mortalities and long recovery times were projected for the larger and longer term scenarios, shorter-term or low level exposures lead to reduced projected impacts. This suggests that efficient monitoring and leak mitigation strategies, coupled with appropriate selection of storage sites can effectively limit concerns regarding localised environmental impacts from CCS. The feedbacks and interactions between physiological and ecological responses simulated reveal that benthic responses to CO2 leakage could be complex. This type of modelling investigation can aid the understanding of impact po...
Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is ... more Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is a leading subject of current research. The effects of acidification on non-calcifying macroalgae are, however, still unclear. The current study reports two 1-month studies using two different macroalgae, the red alga Palmaria palmata (Rhodophyta) and the kelp Saccharina latissima (Phaeophyta), exposed to control (pHNBS = ∼8.04) and increased (pHNBS = ∼7.82) levels of CO2-induced seawater acidification. The impacts of both increased acidification and time of exposure on net primary production (NPP), respiration (R), dimethylsulphoniopropionate (DMSP) concentrations, and algal growth have been assessed. In P. palmata, although NPP significantly increased during the testing period, it significantly decreased with acidification, whereas R showed a significant decrease with acidification only. S. latissima significantly increased NPP with acidification but not with time, and significantly inc...
Increased atmospheric CO2 concentration is leading to changes in the carbonate chemistry and the ... more Increased atmospheric CO2 concentration is leading to changes in the carbonate chemistry and the temperature of the ocean. The impact of these processes on marine organisms will depend on their ability to cope with those changes, particularly the maintenance of calcium carbonate structures. Both a laboratory experiment (long-term exposure to decreased pH and increased temperature) and collections of individuals from natural environments characterized by low pH levels (individuals from intertidal pools and around a CO2 seep) were here coupled to comprehensively study the impact of near-future conditions of pH and temperature on the mechanical properties of the skeleton of the euechinoid sea urchin Paracentrotus lividus. To assess skeletal mechanical properties, we characterized the fracture force, Young's modulus, second moment of area, material nanohardness, and specific Young's modulus of sea urchin test plates. None of these parameters were significantly affected by low pH...
Understanding long-term, ecosystem-level impacts of climate change is challenging because experim... more Understanding long-term, ecosystem-level impacts of climate change is challenging because experimental research frequently focuses on short-term, individual-level impacts in isolation. We address this shortcoming first through an interdisciplinary ensemble of novel experimental techniques to investigate the impacts of 14-month exposure to ocean acidification and warming (OAW) on the physiology, activity, predatory behaviour and susceptibility to predation of an important marine gastropod (Nucella lapillus). We simultaneously estimated the potential impacts of these global drivers on N. lapillus population dynamics and dispersal parameters. We then used these data to parameterize a dynamic bioclimatic envelope model, to investigate the consequences of OAW on the distribution of the species in the wider NE Atlantic region by 2100. The model accounts also for changes in the distribution of resources, suitable habitat and environment simulated by finely resolved biogeochemical models, u...
The distribution patterns of many species in the intertidal zone are partly determined by their a... more The distribution patterns of many species in the intertidal zone are partly determined by their ability to survive and recover from tidal emersion. During emersion most crustaceans experience gill-collapse impairing gas-exchange. Such collapse generates a state of hypoxemia and a hypercapnia-induced respiratory acidosis, leading to hyperlactaemia and metabolic acidosis. However, how such physiological responses to emersion are modified by prior exposure to elevated CO2 and temperature combinations, indicative of future climate change scenarios, is not known. We therefore investigated key physiological responses of velvet swimming crabs, Necora puber, kept for 14 days at one of four pCO2/temperature treatments (400 μatm/10 °C, 1000 μatm/10 °C, 400 μatm/15 °C, 1000 μatm/15 °C), to experimental emersion and recovery. Pre-exposure to elevated pCO2 and temperature increased pre-emersion bicarbonate ion concentrations [HCO3-], increasing resistance to short periods of emersion (90 min). H...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2013
Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric c... more Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric carbon dioxide (CO 2 ) in seawater, is projected to cause significant changes to marine ecology and biogeochemistry. Potential impacts on the microbially driven cycling of nitrogen are of particular concern. Specifically, under seawater pH levels approximating future OA scenarios, rates of ammonia oxidation (the rate-limiting first step of the nitrification pathway) have been shown to dramatically decrease in seawater, but not in underlying sediments. However, no prior study has considered the interactive effects of microbial ammonia oxidation and macrofaunal bioturbation activity, which can enhance nitrogen transformation rates. Using experimental mesocosms, we investigated the responses to OA of ammonia oxidizing microorganisms inhabiting surface sediments and sediments within burrow walls of the mud shrimp Upogebia deltaura . Seawater was acidified to one of four target pH values (pH T...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2013
Climate change may cause ecosystems to become trophically restructured as a result of primary pro... more Climate change may cause ecosystems to become trophically restructured as a result of primary producers and consumers responding differently to increasing CO 2 and temperature. This study used an integrative approach using a controlled microcosm experiment to investigate the combined effects of CO 2 and temperature on key components of the intertidal system in the UK, biofilms and their consumers ( Littorina littorea ). In addition, to identify whether pre-exposure to experimental conditions can alter experimental outcomes we explicitly tested for differential effects on L. littorea pre-exposed to experimental conditions for two weeks and five months. In contrast to predictions based on metabolic theory, the combination of elevated temperature and CO 2 over a five-week period caused a decrease in the amount of primary productivity consumed by grazers, while the abundance of biofilms increased. However, long-term pre-exposure to experimental conditions (five months) altered this effe...
... This community-based mesocosm study supports previ-ous suggestions, based on observations of ... more ... This community-based mesocosm study supports previ-ous suggestions, based on observations of direct physiological impacts, that ocean acidification induced changes in marine biodiversity will be driven by differential vulnerability within and between different taxonomical ...
The purple-tipped sea urchin, Psammechinus miliaris, was exposed to artificially acidified seawat... more The purple-tipped sea urchin, Psammechinus miliaris, was exposed to artificially acidified seawater treatments (pH(w) 6.16, 6.63 or 7.44) over a period of 8 days. Urchin mortality of 100% was observed at pH(w) 6.16 after 7 days and coincided with a pronounced hypercapnia in the coelomic fluid producing an irrecoverable acidosis. Coelomic fluid acid-base measures showed that an accumulation of CO(2) and a significant reduction in pH occurred in all treatments compared with controls. Bicarbonate buffering was employed in each case, reducing the resultant acidosis, but compensation was incomplete even under moderate environmental hypercapnia. Significant test dissolution was inferred from observable increases in the Mg(2+) concentration of the coelomic fluid under all pH treatments. We show that a chronic reduction of surface water pH to below 7.5 would be severely detrimental to the acid-base balance of this predominantly intertidal species; despite its ability to tolerate fluctuations in pCO(2) and pH in the rock pool environment. The absence of respiratory pigment (or any substantial protein in the coelomic fluid), a poor capacity for ionic regulation and dependency on a magnesium calcite test, make echinoids particularly vulnerable to anthropogenic acidification. Geological sequestration leaks may result in dramatic localised pH reductions, e.g. pH 5.8. P. miliaris is intolerant of pH 6.16 seawater and significant mortality is seen at pH 6.63.
Abstract The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on t... more Abstract The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on the global sulphur cycle and may influence local climate through the formation of dimethylsulphide (DMS). However, the effect of global change on DMSP/DMS (DMS (P)) production by algae is not well understood. This study examined the effect of low pH on DMS (P) production and epithelial cell morphology of the free-living red coralline alga Lithothamnion glaciale. Three pH treatments were used in the 80-day experiment:(1) ...
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