Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were ev...Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were evaluated at different levels of pCO2(400 and 800μL L−1)and nutrients(nutrient-enriched and non-enriched seawater).Elevated pCO2 decreased the relative growth rate(RGR),net photosynthetic rate and contents of tissue carbon and tissue nitrogen under non-enriched nutrient conditions,but it had no significant effect on these parameters under nutrient-enriched conditions.The dark respiration rate was positively affected by elevated pCO2 regardless of the nutrient conditions.However,the C:N was unaffected by elevated pCO2 at both nutrient levels.These results implied that ocean acidification could reduce the production and nutrient contents in the tissues of S.japonica,which was associated with nutrient conditions.展开更多
Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in Chi...Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in China,is suffering the harmful golden tide caused by Sargassum horneri.However,it remains unclear whether the detrimental effects of S.horneri on S.japonica cultivation become more severe in future acidified and eutrophic scenario.In this study,we respectively investigated the effects of pCO_(2)(400μatm and 1000μatm)and nutrients(non-enriched and enriched seawater)on the growth,photosynthesis,respiration,chlorophyll contents,and tissue nitrogen of S.japonica and S.horneri.Results indicated that enrichment of nutrients contributed S.horneri to utilize HCO_(3)^(−).The carbon acquisition pathway shifted from HCO_(3)^(−)to CO_(2) in S.japonica,while S.horneri re-mained using HCO_(3)^(−)regulated by nutrient enrichment.S.horneri exhibited better photosynthetic traits than S.japonica,with a higher level of net photosynthetic rate and chlorophyll contents at elevated pCO_(2) and enriched nutrients.Tissue nitrogen also accumulated richly in the thalli of S.horneri under higher pCO_(2) and nutrients.Significant enhancement in growth was only detected in S.horneri under synergistic stress.Together,S.horneri showed competitive dominance in current study.These findings suggest that increasing risk of golden tide in acidified and eutrophic ocean can most likely result in great damage to S.japonica cultivation.展开更多
Due to the elevated atmospheric carbon dioxide, ocean acidification(OA) has recently emerged as a research theme in marine biology due to an expected deleterious effect of altered seawater chemistry on calcification. ...Due to the elevated atmospheric carbon dioxide, ocean acidification(OA) has recently emerged as a research theme in marine biology due to an expected deleterious effect of altered seawater chemistry on calcification. A system simulating future OA scenario is crucial for OA-related studies. Here, we designed an OA-simulated system(OASys) with three solenoid-controlled CO_2 gas channels. The OASys can adjust the pH of the seawater by bubbling CO_2 gas into seawaters via feedback systems. The OASys is very simple in structure with an integrated design and is new-user friendly with the instruction. Moreover, the OASys can monitor and record real-time pH values and can maintain pH levels within 0.02 pH unit. In a 15-d experiment, the OASys was applied to simulate OA in which the expected target pH values were 8.00, 7.80 and 7.60 to study the calcifying response of Galaxea fascicularis. The results showed daily mean seawater pH values held at pH 8.00±0.01, 7.80±0.01 and 7.61±0.01 over15 d. Correspondingly, the coral calcification of G. fascicularis gradually decreased with reduced pH.展开更多
Although the adverse impacts of ocean acidification(OA)on marine calcifiers have been investigated extensively,the anti-stress capabilities regulated by increased light availability are unclear.Herein,the interactive ...Although the adverse impacts of ocean acidification(OA)on marine calcifiers have been investigated extensively,the anti-stress capabilities regulated by increased light availability are unclear.Herein,the interactive effects of three light levels(30μmol photons/(m^(2)·s),150μmol photons/(m^(2)·s),and 240μmol photons/(m^(2)·s)combined with two pCO_(2)concentrations(400 ppmv and 1400 ppmv)on the physiological acclimation of the calcifying macroalga Halimeda opuntia were investigated using a pCO_(2)-light coupling experiment.The OA negatively influenced algal growth,calcification,photosynthesis,and other physiological performances in H.opuntia.The relative growth rate under elevated pCO_(2)conditions significantly declined by 13.14%−41.29%,whereas net calcification rates decreased by nearly three-fold under OA conditions.Notably,increased light availability enhanced stress resistance through the accumulation of soluble organic molecules,especially soluble carbohydrate,soluble protein,and free amino acids,and in combination with metabolic enzyme-driven activities,OA stress was alleviated.The carotenoid content under low light conditions increased markedly,and the rapid light curve of the relative electron transport rate was enhanced significantly by increasing light intensities,indicating that this new organization of the photosynthetic machinery in H.opuntia accommodated light variations and elevated pCO_(2)conditions.Thus,the enhanced metabolic performance of the calcifying macroalga H.opuntia mitigated OA-related stress.展开更多
Ocean acidifi cation(OA)and global warming-induced water column stratification can signifi cantly alter phytoplankton-related biological activity in the marine ecosystem.Yet how these changes may play out in the tropi...Ocean acidifi cation(OA)and global warming-induced water column stratification can signifi cantly alter phytoplankton-related biological activity in the marine ecosystem.Yet how these changes may play out in the tropical Indian Ocean remains unclear.This study investigated the ecological and metabolic responses of the different phytoplankton functional groups to elevated CO_(2) partial pressure and nitrate deficiency in two different environments of the eastern Indian Ocean(EIO).It is revealed that phytoplankton growth and metabolic rates are more sensitive to inorganic nutrients rather than CO_(2).The combined interactive effects of OA and N-limitation on phytoplankton populations are functional groupspecific.In particular,the abundance and calcification rate of calcifying coccolithophores are expected to be enhanced in the future EIO.The underlying mechanisms for this enhancement may be ascribed to coccolithophore’s lower carbon concentrating mechanisms(CCMs)efficiency and OA-induced[HCO^(-)_(3)]increase.In comparison,the abundance of non-calcifying microphytoplankton(e.g.,diatoms and dinoflagellates)and primary productivity would be inhibited under those conditions.Diff erent from previous laboratory experiments,interspecifi c competition for resources would be an important consideration in the natural phytoplankton populations.These combined factors would roughly determine calcifying coccolithophores as“winners”and non-calcifying microphytoplankton as“losers”in the future ocean scenario.Due to the large species-specific differences in phytoplankton sensitivity to OA,comprehensive investigations on oceanic phytoplankton communities are essential to precisely predict phytoplankton ecophysiological response to ocean acidification.展开更多
Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the e...Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the emergence of warm climate and the world-wide disappearance of carbonate platform.展开更多
Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate change.Here we use an Earth system model to examine ...Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate change.Here we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal scenarios.In our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,respectively.Our results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially larger.Simulation results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)change.When CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)decrease.Our study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems.展开更多
With the rapid development of oil,energy,power and other industries,CO_(2) emissions rise sharply,which will cause a large amount of CO_(2) in the air be absorbed by the ocean and lead to ocean acidification.The growt...With the rapid development of oil,energy,power and other industries,CO_(2) emissions rise sharply,which will cause a large amount of CO_(2) in the air be absorbed by the ocean and lead to ocean acidification.The growth and development of organisms can be seriously affected by acidified seawater.Sepia esculenta is a mollusk with high nutritional and economic value and is widely cultured in offshore waters of China.Larvae are the early life forms of the organism and are more vulnerable to changes in the external environment.Too low pH will lead to some adverse reactions in larvae,which will affect metabolism,immune response and other life activities.In this study,we sequenced the transcriptome of S.esculenta subjected to acidified seawater stress and identified 1072differentially expressed genes(DEGs).The detected atypical expression of DEGs substantiates cellular malformation and translocation in S.esculenta under low pH stimulation.Simultaneously,this also substantiates the notable impact of ocean acidification on mollusks.These DEGs were used for functional enrichment analysis of GO and KEGG,and the top twenty items of the biological process classification in GO terms and 11 KEGG signaling pathways were significantly enriched.Finally,the constructed proteinprotein interaction network(PPI)was used to analyze protein-protein interactions,and 12 key DEGs and 3 hub genes were identified.The reliability of 12 genes was verified by quantitative RT-PCR.A comprehensive analysis of the KEGG signaling pathway and PPI revealed that ocean acidification leads to abnormalities in lipid metabolism in S.esculenta larvae,which can lead to cancer development and metastasis,accompanied by some degree of inflammation.The results of the study will help to further investigate the physiological processes of S.esculenta when stimulated by ocean acidification,and provide a reference to cope with the captive breeding of S.esculenta affected by acidification.展开更多
Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an impor...Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an important component of sediment in the continental shelf,while little is known about the impact of ocean acidification on benthic foraminifera both at the community and individual level and associated calcium carbonate deposition.We conducted eight months continued culture experiment under the scenario of 400,800,1200 and 1600 ppm pCO_(2)gradients on living benthic foraminifera from four stations in the continental shelf of the West Pacific Ocean.Statistic results showed OA had a negative effect on the abundance of benthic foraminifera.In contrast,the diversity increased roughly under OA conditions implying OA might stimulate the emergence of rare species and promote community diversity to some extent.In addition,we confirmed that the offshore area wasn’t the refuge for benthic foraminifera while the nearshore one had more resistance to moderate acidification.Calcareous species Protelphidium tuberculatum was the dominant species occupying on average 75%in all treatments and its shell diameter,weight and thickness showed a decrease,indicating the decrease of calcification of benthic foraminifera.A relationship between the weight of P.tuberculatum and pCO_(2)(R^(2)=0.96)was established.Based on the present work,calcareous benthic foraminifera deposited 8.57104 t calcium carbonate per year and this might reduce by nearly half and 90%under 800 and 1200 ppm scenarios,which indicates a biocalcification crisis under ongoing OA.This work shows an analogy for palaeoceanic OA and also provides new insights into the sediment of calcium carbonate in the future.展开更多
To examine the synergetic effects of ocean acidification(OA)and light intensity on the photosynthetic performance of marine diatoms,the marine centric diatom Thalassiosira weissflogii was cultured under ambient low CO...To examine the synergetic effects of ocean acidification(OA)and light intensity on the photosynthetic performance of marine diatoms,the marine centric diatom Thalassiosira weissflogii was cultured under ambient low CO_(2)(LC,390μatm)and elevated high CO_(2)(HC,1000μatm)levels under low-light(LL,60μmol m^(-2)s^(-1))or high-light(HL,220μmol m^(-2)s^(-1))conditions for over 20 generations.HL stimulated the growth rate by 128 and 99%but decreased cell size by 9 and 7%under LC and HC conditions,respectively.However,HC did not change the growth rate under LL but decreased it by 9%under HL.LL combined with HC decreased both maximum quantum yield(FV/FM)and effective quantum yield(ΦPSII),measured under either low or high actinic light.When exposed to UV radiation(UVR),LL-grown cells were more prone to UVA exposure,with higher UVA and UVR inducing inhibition ofΦPSII compared with HL-grown cells.Light use efficiency(α)and maximum relative electron transport rate(rETRmax)were inhibited more in the HC-grown cells when UVR(UVA and UVB)was present,particularly under LL.Our results indicate that the growth light history influences the cell growth and photosynthetic responses to OA and UVR.展开更多
The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse...The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse gases is causing ocean warming,which enhances stratification with thinned upper mixed layers,exposing planktonic organisms to increasing levels of daytime integrated UV radiation.Ocean warming also reduces dissolved oxygen in seawater,resulting in ocean deoxygenation.All these ocean global changes are impacting marine ecosystems and effects are well documented for each individual driver(pH,oxygen,temperature,UV).However,combined effects are still poorly understood,strongly limiting our ability to project impacts at regional or local levels.Different regions are often exposed(and often adapted)to contrastingly different physical and chemical environmental conditions and organisms,and ecosystems from different parts of the world will be exposed to unique combinations of stressors in the future.Understanding the modulating role of adaptation,species niche and stressors’interaction is key.This review,being a non-exhaustively explored one.aims to provide an overview on understandings of ecophysiological effects of OA and its combination with covarying drivers,mainly warming,deoxygenation and solar UV radiation.We propose a testable hypothetical model as well as future research perspectives.展开更多
Over the past decades, the Arctic Ocean has experienced rapid warming under climate change, which has dramatically altered its physical and biogeochemical properties. Reduction in the sea-ice cover is one of the most ...Over the past decades, the Arctic Ocean has experienced rapid warming under climate change, which has dramatically altered its physical and biogeochemical properties. Reduction in the sea-ice cover is one of the most important driving forces of biogeochemical changes in the Arctic Ocean. Between 1999 and 2016, seven Chinese National Arctic Research Expeditions have taken place in the Bering and Chukchi seas, allowing assessment of the biogeochemical response of the western Arctic Ocean to global warming. Herein, we summarize advances in Chinese and international marine biogeochemistry research in the western Arctic Ocean, reviewing results from the Chinese expeditions and highlighting future trends of biogeochemistry in the Pacific Arctic region. The findings reported in this paper contribute towards a better understanding of water masses, greenhouse gases, nutrients, ocean acidification, and organic carbon export and burial processes in this region.展开更多
The problem of ocean acidification caused by the increase of atmospheric carbon dioxide concentration is becoming increasingly prominent.Field observation in the northwest Pacific Ocean was carried out along the 150...The problem of ocean acidification caused by the increase of atmospheric carbon dioxide concentration is becoming increasingly prominent.Field observation in the northwest Pacific Ocean was carried out along the 150°E transect in November 2019.The distribution characteristics and influencing factors of the surface seawater carbonate chemistry,including dissolved inorganic carbon(DIC),total alkalinity(TA),pH,partial pressure of carbon dioxide(pCO_(2))and aragonite saturation state(Ω_(arag))were investigated.DIC and TA ranged from 1915 to 2014μmol kg^(−1)and 2243 to 2291μmol kg^(−1),respectively;DIC in general decreased with decreasing latitude,but TA had no clear latitudinal gradient.pCO_(2)values increased with the decrease of latitude and were all below the atmospheric pCO_(2)level,ranging from 332 to 387μatm.pH on the total hydrogen ion concentration scale(pH_(T))decreased with the decrease of latitude in the range of 8.044–8.110,whileΩ_(arag) increased with the decrease of latitude in the range of 2.61–3.88,suggesting that the spatial distributions of pH_(T) andΩ_(arag) were out of phase.Compared with the present,the predicted values of pH_(T) and Ω_(arag) by the end of this century would decrease remarkedly;larger declines were found in the higher pH_(T) and Ω_(arag) regions,resulting in the differences along the meridional gradient becoming smaller for bothpH_(T) and Ω_(arag).展开更多
Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowin...Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowing species differs between those within or without sediment.In order to fill this gap in our knowledge,we compared shell properties of the infaunal Manila clam(Ruditapes philippinarum)exposed to three pH concentrations(7.4,7.7,and 8.0),within and without sediments.In the first experiment(140 d),clams were exposed to seawater in an acidification system without sediment.A decrease in shell weight corresponding to the increase in dissolution rate was observed in the group ofpH 7.4,at which shell color disappeared or whitened.SEM observations confirmed the changes of the external shell surface.In the second experiment(170 d),sediment was placed at the bottom of each exposure chamber.The effects were found obvious in shell dissolution rate and shell color in the shell specimens exposed to overlying seawater but not found in the shell specimens exposed to sediment.Although the experimental period was longer in the second experiment,shell specimens in the first experiment were more seriously damaged than those in the second experiment under acidic seawater conditions.Our results,in relation to the defense function of the shell,show that marine bivalves in burrowing behavior are more adaptable to seawater acidification than those who do not burrow into sediment.展开更多
As humanity has been polluting the atmosphere with greenhouse gases,the planet is getting warmed up which is triggering the frequency and the intensity of extreme events like heat waves,dry conditions,wildfires,cyclon...As humanity has been polluting the atmosphere with greenhouse gases,the planet is getting warmed up which is triggering the frequency and the intensity of extreme events like heat waves,dry conditions,wildfires,cyclones,tornadoes,lightning,and massive flooding all over the planet Earth.There is considerable evidence that the concentration of greenhouse gases,especially that of CO_(2) has steadily increased in the atmosphere as a result of the indiscriminate use of fossil fuels around the world particularly during the last 70 years.The glaciers in the high mountain and polar regions are diminishing fast,sea levels are rising,and food production is being affected severely in certain parts of the world.In fact,the changing climate has currently become one of the major threats to the survival of civilization.The world scientific communities are warning of a climate emergency and requesting the decision makers to promptly respond and act to sustain life on planet Earth.To deliver net zero emissions by the year 2050,the whole world must phase out the technologies such as coal-powered thermal plants and diesel/petrol/gasoline-powered vehicles which release abundant amounts of CO_(2) and other greenhouse gases into the atmosphere and invest in the development of clean energies such as hydel,wind,solar,space-solar,and nuclear energies.This transition to a low-carbon economy with the help of these technologies together with other technologies such as hydrogen fuel,fuel cells,electric vehicles,and massive plantations is expected to take our planet Earth to a safe zone in the coming 20-30 years.展开更多
The present study was conducted to determine the ef fects of elevated pCO_2 on growth, photosynthesis, dark respiration and inorganic carbon acquisition in the marine microalga D unaliella salina. To accomplish this, ...The present study was conducted to determine the ef fects of elevated pCO_2 on growth, photosynthesis, dark respiration and inorganic carbon acquisition in the marine microalga D unaliella salina. To accomplish this, D. salina was incubated in semi-continuous cultures under present-day CO_2 levels(390 μatm, p HN BS : 8.10), predicted year 2100 CO_2 levels(1 000 μatm, p HN BS : 7.78) and predicted year 2300 CO_2 levels(2 000 μatm, p H NBS : 7.49). Elevated pCO_2 significantly enhanced photosynthesis(in terms of gross photosynthetic O_2 evolution, ef fective quantum yield(ΔF/F' m), photosynthetic efficiency( α), maximum relative electron transport rate(r ETRm ax) and ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco) activity) and dark respiration of D. salina, but had insignificant effects on growth. The photosynthetic O_2 evolution of D. salina was significantly inhibited by the inhibitors acetazolamide(AZ), ethoxyzolamide(EZ) and 4,4'-diisothiocyanostilbene-2,2′-disulfonate(DIDS), indicating that D. salina is capable of acquiring HCO ˉ 3 via extracellular carbonic anhydrase and anion-exchange proteins. Furthermore, the lower inhibition of the photosynthetic O2 evolution at high pCO_2 levels by AZ, EZ and DIDS and the decreased carbonic anhydrase showed that carbon concentrating mechanisms were down-regulated at high pCO_2. In conclusion, our results show that photosynthesis, dark respiration and CCMs will be af fected by the increased pCO_2/low p H conditions predicted for the future, but that the responses of D. salina to high pCO_2/low p H might be modulated by other environmental factors such as light, nutrients and temperature. Therefore, further studies are needed to determine the interactive eff ects of pCO_2, temperature, light and nutrients on marine microalgae.展开更多
To understand the ecological status and macrobenthic assemblages of the Xin'an River Estuary and its adjacent waters, a survey was conducted for environmental variables and macrobenthic assemblage structure in Septem...To understand the ecological status and macrobenthic assemblages of the Xin'an River Estuary and its adjacent waters, a survey was conducted for environmental variables and macrobenthic assemblage structure in September 2012(Yantai, China). Several methods are adopted in the data analysis process: dominance index,diversity indices, cluster analysis, non-metric multi-dimentional scaling ordination, AMBI and M-AMBI. The dissolved inorganic nitrogen and soluble reactive phosphorus of six out of eight sampling stations were in a good condition with low concentration. The average value of DO((2.89±0.60) mg/L) and p H(4.28±0.43) indicated that the research area faced with the risk of ocean acidification and underlying hypoxia. A total of 62 species were identified, of which the dominant species group was polychaetes. The average abundance and biomass was577.50 ind./m^2 and 6.01 g/m^2, respectively. Compared with historical data, the macrobenthic assemblage structure at waters around the Xin'an River Estuary was in a relatively stable status from 2009 to 2012.Contaminant indicator species Capitella capitata appeared at Sta. Y1, indicating the animals here suffered from hypoxia and acidification. AMBI and M-AMBI results showed that most sampling stations were slightly disturbed,which were coincided with the abiotic measurement on evaluating the health conditions. Macrobenthic communities suffered pressures from ocean acidification and hypoxia at the research waters, particularly those at Stas Y1, Y2 and Y5, which displays negative results in benthic health evaluation.展开更多
Several studies have demonstrated that shellfish calcification rate has been impacted by ocean acidification. However, the carbonate system variables responsible for regulating calcification rate are controversial. To...Several studies have demonstrated that shellfish calcification rate has been impacted by ocean acidification. However, the carbonate system variables responsible for regulating calcification rate are controversial. To distinguish the key variables, we manipulated a seawater carbonate system by regulating seawater pH and dissolved inorganic carbon(DIC). Calcification rates of juvenile blue mussel(M ytilus edulis) and Zhikong scallop(C hlamys farreri) were measured in different carbonate systems. Our results demonstrated that neither [HCO ˉ^+ 3 ], DIC, or p H([H ^+ ]) were determining factors for the shellfish calcification rate of blue mussel or Zhikong scallop. However, a significant correlation was detected between calcification rate and DIC/[H ^+ ] and [CO_3^(2ˉ)] in both species.展开更多
An increase in the level of atmospheric carbon dioxide (CO2) and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower p...An increase in the level of atmospheric carbon dioxide (CO2) and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower pH in seawater and may affect the physiology of seaweed species. Accordingly, the main goal of the current study was to determine the physiological responses of Bryopsis plumosa to elevated-CO2. The results indicated that photosynthesis of B. plumosa was insignificantly affected to elevated-CO2, but photosynthetic pigment contents and phenolics were significantly decreased. The results obtained from the research reveal that B. plumosa may become physiologically advanced when exposed to CO2-induced ocean acidification. In particular, B. plumosa may be more able to compete with calcifying algae when it will become future predicted CO2 scenario.展开更多
pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,s...pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,sea ice),a better understanding of the temperature change on pH under extreme conditions is needed.The objective of this paper was to investigate the temperature coefficient of the seawater pH(△pH/△T)over a wide range of temperature,pH,dissolved inorganic carbon(DIC)and salinity by a method of continuous pH measurement with the temperature change,and to verify the application of CO2SYS for pH conversion under extreme conditions(on the National Bureau of Standards(NBS)scale and the total proton scale).Both experimental results and CO2SYS calculations showed that△pH/△T was slightly affected by temperature over the range of 0℃ to 40℃ and by pH(at 25℃)from 7.8 to 8.5.However,when pH was out of this range,△pH/△T varied greatly with pH value.According to the experimental results,changes in DIC from 1 mmol/kg to 5 mmol/kg and salinity from 20 to 105 had no significant effect on△pH/△T.CO2SYS calculations showed a slight increase in△pH/△T with DIC on both the NBS scale and the total proton scale;and underestimated△pH/△T at high salinity(i.e.,beyond the oceanographic range)on the NBS scale.Nevertheless,CO2SYS is still suitable for pH conversion even under extreme conditions by simply setting the input values of DIC and salinity in CO2SYS within the oceanographic range(e.g.,DIC=2 mmol/kg and S=35).展开更多
基金Ocean University of China in 2018 and the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020708).
文摘Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were evaluated at different levels of pCO2(400 and 800μL L−1)and nutrients(nutrient-enriched and non-enriched seawater).Elevated pCO2 decreased the relative growth rate(RGR),net photosynthetic rate and contents of tissue carbon and tissue nitrogen under non-enriched nutrient conditions,but it had no significant effect on these parameters under nutrient-enriched conditions.The dark respiration rate was positively affected by elevated pCO2 regardless of the nutrient conditions.However,the C:N was unaffected by elevated pCO2 at both nutrient levels.These results implied that ocean acidification could reduce the production and nutrient contents in the tissues of S.japonica,which was associated with nutrient conditions.
基金This work is funded by the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020708).
文摘Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in China,is suffering the harmful golden tide caused by Sargassum horneri.However,it remains unclear whether the detrimental effects of S.horneri on S.japonica cultivation become more severe in future acidified and eutrophic scenario.In this study,we respectively investigated the effects of pCO_(2)(400μatm and 1000μatm)and nutrients(non-enriched and enriched seawater)on the growth,photosynthesis,respiration,chlorophyll contents,and tissue nitrogen of S.japonica and S.horneri.Results indicated that enrichment of nutrients contributed S.horneri to utilize HCO_(3)^(−).The carbon acquisition pathway shifted from HCO_(3)^(−)to CO_(2) in S.japonica,while S.horneri re-mained using HCO_(3)^(−)regulated by nutrient enrichment.S.horneri exhibited better photosynthetic traits than S.japonica,with a higher level of net photosynthetic rate and chlorophyll contents at elevated pCO_(2) and enriched nutrients.Tissue nitrogen also accumulated richly in the thalli of S.horneri under higher pCO_(2) and nutrients.Significant enhancement in growth was only detected in S.horneri under synergistic stress.Together,S.horneri showed competitive dominance in current study.These findings suggest that increasing risk of golden tide in acidified and eutrophic ocean can most likely result in great damage to S.japonica cultivation.
基金The China-ASEAN Maritime Cooperation Fund Project "China-ASEAN Countries Collaboration on Marine Endangered Species Researches" and "China-ASEAN Marine Protected Areas Ecosystem Management Network"Regional Demonstration of Marine Economy Innovative Development Project under contract No.16PZY002SF18+1 种基金the China-Indonesia Maritime Cooperation Fund Project "China-Indonesia Bitung Ecological Station Establishment"the National Natural Science Foundation of China under contract No.41506123
文摘Due to the elevated atmospheric carbon dioxide, ocean acidification(OA) has recently emerged as a research theme in marine biology due to an expected deleterious effect of altered seawater chemistry on calcification. A system simulating future OA scenario is crucial for OA-related studies. Here, we designed an OA-simulated system(OASys) with three solenoid-controlled CO_2 gas channels. The OASys can adjust the pH of the seawater by bubbling CO_2 gas into seawaters via feedback systems. The OASys is very simple in structure with an integrated design and is new-user friendly with the instruction. Moreover, the OASys can monitor and record real-time pH values and can maintain pH levels within 0.02 pH unit. In a 15-d experiment, the OASys was applied to simulate OA in which the expected target pH values were 8.00, 7.80 and 7.60 to study the calcifying response of Galaxea fascicularis. The results showed daily mean seawater pH values held at pH 8.00±0.01, 7.80±0.01 and 7.61±0.01 over15 d. Correspondingly, the coral calcification of G. fascicularis gradually decreased with reduced pH.
基金The National Natural Science Foundation of China under contract No.42006129the Guangzhou Science and Technology Project under contract No.202102021228+2 种基金the National Key Research and Development Project of China under contract No.2021YFC3100500the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0404the Special Research Assistant Grant Program of the Chinese Academy of Sciences.
文摘Although the adverse impacts of ocean acidification(OA)on marine calcifiers have been investigated extensively,the anti-stress capabilities regulated by increased light availability are unclear.Herein,the interactive effects of three light levels(30μmol photons/(m^(2)·s),150μmol photons/(m^(2)·s),and 240μmol photons/(m^(2)·s)combined with two pCO_(2)concentrations(400 ppmv and 1400 ppmv)on the physiological acclimation of the calcifying macroalga Halimeda opuntia were investigated using a pCO_(2)-light coupling experiment.The OA negatively influenced algal growth,calcification,photosynthesis,and other physiological performances in H.opuntia.The relative growth rate under elevated pCO_(2)conditions significantly declined by 13.14%−41.29%,whereas net calcification rates decreased by nearly three-fold under OA conditions.Notably,increased light availability enhanced stress resistance through the accumulation of soluble organic molecules,especially soluble carbohydrate,soluble protein,and free amino acids,and in combination with metabolic enzyme-driven activities,OA stress was alleviated.The carotenoid content under low light conditions increased markedly,and the rapid light curve of the relative electron transport rate was enhanced significantly by increasing light intensities,indicating that this new organization of the photosynthetic machinery in H.opuntia accommodated light variations and elevated pCO_(2)conditions.Thus,the enhanced metabolic performance of the calcifying macroalga H.opuntia mitigated OA-related stress.
基金Supported by the National Natural Science Foundation of China(Nos.41876134,41676112,41276124,41706184)the Changjiang Scholar Program of Chinese Ministry of Education of China(No.T2014253)to Jun SUN。
文摘Ocean acidifi cation(OA)and global warming-induced water column stratification can signifi cantly alter phytoplankton-related biological activity in the marine ecosystem.Yet how these changes may play out in the tropical Indian Ocean remains unclear.This study investigated the ecological and metabolic responses of the different phytoplankton functional groups to elevated CO_(2) partial pressure and nitrate deficiency in two different environments of the eastern Indian Ocean(EIO).It is revealed that phytoplankton growth and metabolic rates are more sensitive to inorganic nutrients rather than CO_(2).The combined interactive effects of OA and N-limitation on phytoplankton populations are functional groupspecific.In particular,the abundance and calcification rate of calcifying coccolithophores are expected to be enhanced in the future EIO.The underlying mechanisms for this enhancement may be ascribed to coccolithophore’s lower carbon concentrating mechanisms(CCMs)efficiency and OA-induced[HCO^(-)_(3)]increase.In comparison,the abundance of non-calcifying microphytoplankton(e.g.,diatoms and dinoflagellates)and primary productivity would be inhibited under those conditions.Diff erent from previous laboratory experiments,interspecifi c competition for resources would be an important consideration in the natural phytoplankton populations.These combined factors would roughly determine calcifying coccolithophores as“winners”and non-calcifying microphytoplankton as“losers”in the future ocean scenario.Due to the large species-specific differences in phytoplankton sensitivity to OA,comprehensive investigations on oceanic phytoplankton communities are essential to precisely predict phytoplankton ecophysiological response to ocean acidification.
基金financially supported by the National Science Foundation of China(grant No.41572089)
文摘Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the emergence of warm climate and the world-wide disappearance of carbonate platform.
基金supported by the National Natural Science Foundation of China(Nos.41975103,42275179,22022611,and 42005027)the Zhejiang Provincial Natural Science Foundation of China(No.LQ20D050003)。
文摘Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate change.Here we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal scenarios.In our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,respectively.Our results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially larger.Simulation results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)change.When CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)decrease.Our study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems.
基金funded by the Ministry of Agriculture of the People’s Republic of China (No.CARS-49)。
文摘With the rapid development of oil,energy,power and other industries,CO_(2) emissions rise sharply,which will cause a large amount of CO_(2) in the air be absorbed by the ocean and lead to ocean acidification.The growth and development of organisms can be seriously affected by acidified seawater.Sepia esculenta is a mollusk with high nutritional and economic value and is widely cultured in offshore waters of China.Larvae are the early life forms of the organism and are more vulnerable to changes in the external environment.Too low pH will lead to some adverse reactions in larvae,which will affect metabolism,immune response and other life activities.In this study,we sequenced the transcriptome of S.esculenta subjected to acidified seawater stress and identified 1072differentially expressed genes(DEGs).The detected atypical expression of DEGs substantiates cellular malformation and translocation in S.esculenta under low pH stimulation.Simultaneously,this also substantiates the notable impact of ocean acidification on mollusks.These DEGs were used for functional enrichment analysis of GO and KEGG,and the top twenty items of the biological process classification in GO terms and 11 KEGG signaling pathways were significantly enriched.Finally,the constructed proteinprotein interaction network(PPI)was used to analyze protein-protein interactions,and 12 key DEGs and 3 hub genes were identified.The reliability of 12 genes was verified by quantitative RT-PCR.A comprehensive analysis of the KEGG signaling pathway and PPI revealed that ocean acidification leads to abnormalities in lipid metabolism in S.esculenta larvae,which can lead to cancer development and metastasis,accompanied by some degree of inflammation.The results of the study will help to further investigate the physiological processes of S.esculenta when stimulated by ocean acidification,and provide a reference to cope with the captive breeding of S.esculenta affected by acidification.
基金supports from the following projects:the National Natural Science Foundation of China(Nos.41976058,U1906211)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)Natural Science Foundation of Shandong Province(Grant No.ZR2021QD004)。
文摘Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an important component of sediment in the continental shelf,while little is known about the impact of ocean acidification on benthic foraminifera both at the community and individual level and associated calcium carbonate deposition.We conducted eight months continued culture experiment under the scenario of 400,800,1200 and 1600 ppm pCO_(2)gradients on living benthic foraminifera from four stations in the continental shelf of the West Pacific Ocean.Statistic results showed OA had a negative effect on the abundance of benthic foraminifera.In contrast,the diversity increased roughly under OA conditions implying OA might stimulate the emergence of rare species and promote community diversity to some extent.In addition,we confirmed that the offshore area wasn’t the refuge for benthic foraminifera while the nearshore one had more resistance to moderate acidification.Calcareous species Protelphidium tuberculatum was the dominant species occupying on average 75%in all treatments and its shell diameter,weight and thickness showed a decrease,indicating the decrease of calcification of benthic foraminifera.A relationship between the weight of P.tuberculatum and pCO_(2)(R^(2)=0.96)was established.Based on the present work,calcareous benthic foraminifera deposited 8.57104 t calcium carbonate per year and this might reduce by nearly half and 90%under 800 and 1200 ppm scenarios,which indicates a biocalcification crisis under ongoing OA.This work shows an analogy for palaeoceanic OA and also provides new insights into the sediment of calcium carbonate in the future.
基金This study was supported by the National Natural Science Foundation of China(41720104005,41721005,41890803)Key Research and Development Program of Anhui Province(202004i07020004)+3 种基金Excellent Youth Scholars Support Program of Anhui Province(gxyq2021212)MEL Visiting Fellowship Program(MELRS2008)Research Platform of Eco-Environmental Protection Research Centre of Xin’an River Basin,Huangshan University(kypt202102)The authors are grateful to the laboratory engineers Xianglan Zeng and Wenyan Zhao for their logistical and technical support.
文摘To examine the synergetic effects of ocean acidification(OA)and light intensity on the photosynthetic performance of marine diatoms,the marine centric diatom Thalassiosira weissflogii was cultured under ambient low CO_(2)(LC,390μatm)and elevated high CO_(2)(HC,1000μatm)levels under low-light(LL,60μmol m^(-2)s^(-1))or high-light(HL,220μmol m^(-2)s^(-1))conditions for over 20 generations.HL stimulated the growth rate by 128 and 99%but decreased cell size by 9 and 7%under LC and HC conditions,respectively.However,HC did not change the growth rate under LL but decreased it by 9%under HL.LL combined with HC decreased both maximum quantum yield(FV/FM)and effective quantum yield(ΦPSII),measured under either low or high actinic light.When exposed to UV radiation(UVR),LL-grown cells were more prone to UVA exposure,with higher UVA and UVR inducing inhibition ofΦPSII compared with HL-grown cells.Light use efficiency(α)and maximum relative electron transport rate(rETRmax)were inhibited more in the HC-grown cells when UVR(UVA and UVB)was present,particularly under LL.Our results indicate that the growth light history influences the cell growth and photosynthetic responses to OA and UVR.
基金This study was supported by the National Natural Science Foundation of China(Nos 41720104005,41721005,31872587)the Joint Project of National Natural Science Foundation of China and Shandong Province(No.U1606404)+1 种基金the Shanghai Pujiang Talent Program(18PJ1404000)Shanghai Municipal Natural Science Foundation(17ZR1412900).
文摘The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse gases is causing ocean warming,which enhances stratification with thinned upper mixed layers,exposing planktonic organisms to increasing levels of daytime integrated UV radiation.Ocean warming also reduces dissolved oxygen in seawater,resulting in ocean deoxygenation.All these ocean global changes are impacting marine ecosystems and effects are well documented for each individual driver(pH,oxygen,temperature,UV).However,combined effects are still poorly understood,strongly limiting our ability to project impacts at regional or local levels.Different regions are often exposed(and often adapted)to contrastingly different physical and chemical environmental conditions and organisms,and ecosystems from different parts of the world will be exposed to unique combinations of stressors in the future.Understanding the modulating role of adaptation,species niche and stressors’interaction is key.This review,being a non-exhaustively explored one.aims to provide an overview on understandings of ecophysiological effects of OA and its combination with covarying drivers,mainly warming,deoxygenation and solar UV radiation.We propose a testable hypothetical model as well as future research perspectives.
基金the National Natural Science Foundation of China (Grant nos. 41506222, 41776205, 41606052, 41606211)Chinese Polar Environment Comprehensive Investigation & Assessment Programs (Grant nos. CHINARE2017-03-04, 2017-04-03)the Fundamental Research Funds for the Second Institute of Oceanography, SOA (Grant nos. JG1611, JG1502)
文摘Over the past decades, the Arctic Ocean has experienced rapid warming under climate change, which has dramatically altered its physical and biogeochemical properties. Reduction in the sea-ice cover is one of the most important driving forces of biogeochemical changes in the Arctic Ocean. Between 1999 and 2016, seven Chinese National Arctic Research Expeditions have taken place in the Bering and Chukchi seas, allowing assessment of the biogeochemical response of the western Arctic Ocean to global warming. Herein, we summarize advances in Chinese and international marine biogeochemistry research in the western Arctic Ocean, reviewing results from the Chinese expeditions and highlighting future trends of biogeochemistry in the Pacific Arctic region. The findings reported in this paper contribute towards a better understanding of water masses, greenhouse gases, nutrients, ocean acidification, and organic carbon export and burial processes in this region.
基金supported by the Key Research and Development Program of Shandong Province(No.2020 ZLYS04)the National Key Research and Development Program of China(No.2017YFA0604300)+2 种基金the Qingdao Pilot National Laboratory for Marine Science and Technology(No.2018SDKJ0105-1)the Fundamental Research Funds for the Central Universities(No.202072001)the Young Scholars Program of Shandong University(No.2018WLJH43).
文摘The problem of ocean acidification caused by the increase of atmospheric carbon dioxide concentration is becoming increasingly prominent.Field observation in the northwest Pacific Ocean was carried out along the 150°E transect in November 2019.The distribution characteristics and influencing factors of the surface seawater carbonate chemistry,including dissolved inorganic carbon(DIC),total alkalinity(TA),pH,partial pressure of carbon dioxide(pCO_(2))and aragonite saturation state(Ω_(arag))were investigated.DIC and TA ranged from 1915 to 2014μmol kg^(−1)and 2243 to 2291μmol kg^(−1),respectively;DIC in general decreased with decreasing latitude,but TA had no clear latitudinal gradient.pCO_(2)values increased with the decrease of latitude and were all below the atmospheric pCO_(2)level,ranging from 332 to 387μatm.pH on the total hydrogen ion concentration scale(pH_(T))decreased with the decrease of latitude in the range of 8.044–8.110,whileΩ_(arag) increased with the decrease of latitude in the range of 2.61–3.88,suggesting that the spatial distributions of pH_(T) andΩ_(arag) were out of phase.Compared with the present,the predicted values of pH_(T) and Ω_(arag) by the end of this century would decrease remarkedly;larger declines were found in the higher pH_(T) and Ω_(arag) regions,resulting in the differences along the meridional gradient becoming smaller for bothpH_(T) and Ω_(arag).
基金Supported by the earmarked fund for Modern Agro-industry Technology Research System(No.CARS-48)
文摘Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowing species differs between those within or without sediment.In order to fill this gap in our knowledge,we compared shell properties of the infaunal Manila clam(Ruditapes philippinarum)exposed to three pH concentrations(7.4,7.7,and 8.0),within and without sediments.In the first experiment(140 d),clams were exposed to seawater in an acidification system without sediment.A decrease in shell weight corresponding to the increase in dissolution rate was observed in the group ofpH 7.4,at which shell color disappeared or whitened.SEM observations confirmed the changes of the external shell surface.In the second experiment(170 d),sediment was placed at the bottom of each exposure chamber.The effects were found obvious in shell dissolution rate and shell color in the shell specimens exposed to overlying seawater but not found in the shell specimens exposed to sediment.Although the experimental period was longer in the second experiment,shell specimens in the first experiment were more seriously damaged than those in the second experiment under acidic seawater conditions.Our results,in relation to the defense function of the shell,show that marine bivalves in burrowing behavior are more adaptable to seawater acidification than those who do not burrow into sediment.
文摘As humanity has been polluting the atmosphere with greenhouse gases,the planet is getting warmed up which is triggering the frequency and the intensity of extreme events like heat waves,dry conditions,wildfires,cyclones,tornadoes,lightning,and massive flooding all over the planet Earth.There is considerable evidence that the concentration of greenhouse gases,especially that of CO_(2) has steadily increased in the atmosphere as a result of the indiscriminate use of fossil fuels around the world particularly during the last 70 years.The glaciers in the high mountain and polar regions are diminishing fast,sea levels are rising,and food production is being affected severely in certain parts of the world.In fact,the changing climate has currently become one of the major threats to the survival of civilization.The world scientific communities are warning of a climate emergency and requesting the decision makers to promptly respond and act to sustain life on planet Earth.To deliver net zero emissions by the year 2050,the whole world must phase out the technologies such as coal-powered thermal plants and diesel/petrol/gasoline-powered vehicles which release abundant amounts of CO_(2) and other greenhouse gases into the atmosphere and invest in the development of clean energies such as hydel,wind,solar,space-solar,and nuclear energies.This transition to a low-carbon economy with the help of these technologies together with other technologies such as hydrogen fuel,fuel cells,electric vehicles,and massive plantations is expected to take our planet Earth to a safe zone in the coming 20-30 years.
基金Supported by the Joint Funds of the National Natural Science Foundation of China and the Marine Science Research Center of the People’s Government of Shandong Province(No.U1406403)the National Natural Science Foundation of China(No.41476091)
文摘The present study was conducted to determine the ef fects of elevated pCO_2 on growth, photosynthesis, dark respiration and inorganic carbon acquisition in the marine microalga D unaliella salina. To accomplish this, D. salina was incubated in semi-continuous cultures under present-day CO_2 levels(390 μatm, p HN BS : 8.10), predicted year 2100 CO_2 levels(1 000 μatm, p HN BS : 7.78) and predicted year 2300 CO_2 levels(2 000 μatm, p H NBS : 7.49). Elevated pCO_2 significantly enhanced photosynthesis(in terms of gross photosynthetic O_2 evolution, ef fective quantum yield(ΔF/F' m), photosynthetic efficiency( α), maximum relative electron transport rate(r ETRm ax) and ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco) activity) and dark respiration of D. salina, but had insignificant effects on growth. The photosynthetic O_2 evolution of D. salina was significantly inhibited by the inhibitors acetazolamide(AZ), ethoxyzolamide(EZ) and 4,4'-diisothiocyanostilbene-2,2′-disulfonate(DIDS), indicating that D. salina is capable of acquiring HCO ˉ 3 via extracellular carbonic anhydrase and anion-exchange proteins. Furthermore, the lower inhibition of the photosynthetic O2 evolution at high pCO_2 levels by AZ, EZ and DIDS and the decreased carbonic anhydrase showed that carbon concentrating mechanisms were down-regulated at high pCO_2. In conclusion, our results show that photosynthesis, dark respiration and CCMs will be af fected by the increased pCO_2/low p H conditions predicted for the future, but that the responses of D. salina to high pCO_2/low p H might be modulated by other environmental factors such as light, nutrients and temperature. Therefore, further studies are needed to determine the interactive eff ects of pCO_2, temperature, light and nutrients on marine microalgae.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences under contract Nos XDA11020403 and XDA1102702the Key Research Program of the Chinese Academy of Sciences under contract No.KZZD-EW-14+2 种基金the NSFC-NOW “Water Ways,Harbours,Estuaries and Coastal Engineering” Scheme co-supported by the National Natural Science Foundation of China under contract No.NSFC41061130543the Netherlands Organization for Scientific Research under contract No.843.10.003the International Cooperation,CAS,Chinese-Foreign Cooperation in Key Projects under contract No.133337KYSB20160002
文摘To understand the ecological status and macrobenthic assemblages of the Xin'an River Estuary and its adjacent waters, a survey was conducted for environmental variables and macrobenthic assemblage structure in September 2012(Yantai, China). Several methods are adopted in the data analysis process: dominance index,diversity indices, cluster analysis, non-metric multi-dimentional scaling ordination, AMBI and M-AMBI. The dissolved inorganic nitrogen and soluble reactive phosphorus of six out of eight sampling stations were in a good condition with low concentration. The average value of DO((2.89±0.60) mg/L) and p H(4.28±0.43) indicated that the research area faced with the risk of ocean acidification and underlying hypoxia. A total of 62 species were identified, of which the dominant species group was polychaetes. The average abundance and biomass was577.50 ind./m^2 and 6.01 g/m^2, respectively. Compared with historical data, the macrobenthic assemblage structure at waters around the Xin'an River Estuary was in a relatively stable status from 2009 to 2012.Contaminant indicator species Capitella capitata appeared at Sta. Y1, indicating the animals here suffered from hypoxia and acidification. AMBI and M-AMBI results showed that most sampling stations were slightly disturbed,which were coincided with the abiotic measurement on evaluating the health conditions. Macrobenthic communities suffered pressures from ocean acidification and hypoxia at the research waters, particularly those at Stas Y1, Y2 and Y5, which displays negative results in benthic health evaluation.
基金Supported by the Special Scientific Research Funds for Central Nonprofit Institutes,CAFS(No.2014A01YY01)the National Natural Science Foundation of China(No.41606194)+4 种基金the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the Earmarked Fund for Modern Agro-Industry Technology Research System(No.CARS-48)the National Marine Public Welfare Research Project(Nos.201305043,201205031)the National Key Technology Research and Development Program of China(No.2011BAD13B02)the Scientific and Technological Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘Several studies have demonstrated that shellfish calcification rate has been impacted by ocean acidification. However, the carbonate system variables responsible for regulating calcification rate are controversial. To distinguish the key variables, we manipulated a seawater carbonate system by regulating seawater pH and dissolved inorganic carbon(DIC). Calcification rates of juvenile blue mussel(M ytilus edulis) and Zhikong scallop(C hlamys farreri) were measured in different carbonate systems. Our results demonstrated that neither [HCO ˉ^+ 3 ], DIC, or p H([H ^+ ]) were determining factors for the shellfish calcification rate of blue mussel or Zhikong scallop. However, a significant correlation was detected between calcification rate and DIC/[H ^+ ] and [CO_3^(2ˉ)] in both species.
基金The Uludag University Scientific Research Project Unit through the research project of UAP(F)2011/79
文摘An increase in the level of atmospheric carbon dioxide (CO2) and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower pH in seawater and may affect the physiology of seaweed species. Accordingly, the main goal of the current study was to determine the physiological responses of Bryopsis plumosa to elevated-CO2. The results indicated that photosynthesis of B. plumosa was insignificantly affected to elevated-CO2, but photosynthetic pigment contents and phenolics were significantly decreased. The results obtained from the research reveal that B. plumosa may become physiologically advanced when exposed to CO2-induced ocean acidification. In particular, B. plumosa may be more able to compete with calcifying algae when it will become future predicted CO2 scenario.
基金The National Natural Science Foundation of China under contract No.41806094the Young Scholars Program of Shandong University under contract No.2018WLJH43。
文摘pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,sea ice),a better understanding of the temperature change on pH under extreme conditions is needed.The objective of this paper was to investigate the temperature coefficient of the seawater pH(△pH/△T)over a wide range of temperature,pH,dissolved inorganic carbon(DIC)and salinity by a method of continuous pH measurement with the temperature change,and to verify the application of CO2SYS for pH conversion under extreme conditions(on the National Bureau of Standards(NBS)scale and the total proton scale).Both experimental results and CO2SYS calculations showed that△pH/△T was slightly affected by temperature over the range of 0℃ to 40℃ and by pH(at 25℃)from 7.8 to 8.5.However,when pH was out of this range,△pH/△T varied greatly with pH value.According to the experimental results,changes in DIC from 1 mmol/kg to 5 mmol/kg and salinity from 20 to 105 had no significant effect on△pH/△T.CO2SYS calculations showed a slight increase in△pH/△T with DIC on both the NBS scale and the total proton scale;and underestimated△pH/△T at high salinity(i.e.,beyond the oceanographic range)on the NBS scale.Nevertheless,CO2SYS is still suitable for pH conversion even under extreme conditions by simply setting the input values of DIC and salinity in CO2SYS within the oceanographic range(e.g.,DIC=2 mmol/kg and S=35).