共查询到19条相似文献，搜索用时 125 毫秒
1.
长心卡帕藻(Kappaphycusalvarezii)是主要生长于热带海域的大型经济红藻,在营养物生物提取方面具有重要的经济和生态价值,作为提取κ-卡拉胶的重要原料,广泛应用于食品和医学等多种行业。由于人类活动导致大气中CO2浓度持续升高,引发海洋表层海水逐渐酸化和升温,对大型海藻产生耦合效应。因此,本文设置了两种CO2浓度梯度(450×10–6和1 200×10–6)和三种温度梯度(26℃、29℃和32℃),从光合作用、细胞代谢产物、碳氮积累和酶活性方面探讨长心卡帕藻响应海洋酸化和海水升温的环境适应性变化。结果表明, CO2浓度与温度变化对长心卡帕藻的Fv/Fm影响显著(P<0.05),在两种CO2浓度条件下,Fv/Fm均随温度升高而增加;酸化条件与非酸化条件下可溶性糖浓度变化趋势相反,海水升温对游离氨基酸浓度影响极显著(P<0.01),在两种CO2水平下,升温均会降低藻体游离... 相似文献
2.
大气CO2浓度升高引起的海洋酸化可能对浮游植物造成不同程度的影响。而近海浮游植物不仅面临着海水酸化问题，还会受到海水溶解性CO2降低及pH升高(海水碱化)的影响。本实验以斑点海链藻(Thalassiosira punctigera)为研究对象，测定7个不同pCO2水平(25 μatm、50 μatm、100 μatm、200 μatm、400 μatm、800 μatm、1 600 μatm)下的生长、光合作用和呼吸作用速率、细胞粒径、叶绿素a和生物硅含量以及叶绿素荧光等参数。结果表明，与400 μatm相比，在海水酸化(pCO2 > 400 μatm)和海水碱化(pCO2 < 400 μatm) 条件下，斑点海链藻的生长速率和叶绿素a含量都显著降低，但是碱化条件下降低的程度更大。此外，碱化处理的藻细胞光合作用速率、最大量子产量(Fv/Fm)和最大相对电子传递速率(rETRmax)都显著低于400 μatm培养下的细胞，而呼吸作用速率显著升高，但是生物硅含量和细胞大小无明显变化。研究表明海水碱化和海水酸化均会抑制其生理活动，而且海水碱化对其影响更显著。这表明正常pCO2生长下的藻细胞具有最适的生理状态。本研究可为探究海水碳酸盐系统变化对海洋初级生产力的影响提供一定的数据支持。 相似文献
3.
CO2升高和阳光紫外辐射对坛紫菜生长和光合特性的耦合效应 总被引：1，自引：0，他引：1
大气CO2持续升高,导致溶入海水中的CO2增多,海水表层的H+浓度增加,从而引起海洋酸化。为了探讨近岸定生大型海藻对这种环境变化的响应,本文选择经济海藻坛紫菜为实验材料,研究海洋酸化与紫外辐射对藻体生长以及光合特性的影响。实验分两个CO2处理,分别为正常空气水平(390 ppmv)和高CO2水平(800 ppmv); 三种辐射处理,分别为全波长辐射(PAB)、滤除紫外线B(PA)和仅接受可见光处理(PAR)。研究结果表明,CO2培养下的坛紫菜,在仅有可见光(P)或者同时有紫外线A(PA)存在的情况下,显著促进藻体的生长;但在全波长辐射处理下(PAB),这种作用不明显。高CO2降低了藻体在P和PA处理下的光合作用速率,但对PAB处理作用不显著。高CO2处理下的藻体,UV-B显著降低了全波长辐射下藻体紫外吸收物质的含量,但在正常CO2水平下,紫外辐射的作用不显著。这表明高CO2导致的生长优势被紫外辐射的负面效应所抵消,在全球变化的过程中,紫外辐射的进一步加强在海洋酸化的背景下甚至有可能降低坛紫菜的产量。 相似文献
4.
急性CO2酸化对菲律宾蛤仔钙壳和呼吸作用的影响 总被引：1，自引：1，他引：0
基于渤海表层典型的碳酸盐系统,通过实验室密闭培养实验,分析急性CO2酸化条件对菲律宾蛤仔(Ruditapes philippinarum) CaCO3形成速率(G)和CO2呼吸速率(RC)的影响,以探讨局部海域CO2酸化的底层海水在潮流或者风海流等因素的驱动下,脉冲式影响贝类栖息地时养殖贝类可能的响应。结果表明,菲律宾蛤仔在急性CO2酸化条件下发生轻微的钙壳溶解和显著的呼吸抑制。CO2酸化和菲律宾蛤仔的呼吸作用共同驱动钙壳溶解,溶解速率随Ω文石下降而升高,G(μmol/(FWg·h))=0.14 × Ω文石-0.49 (n=12, r=0.95, p<0.01)。活体菲律宾蛤仔钙壳保持稳定的Ω文石临界值为3.5,而在Ω文石=1.0的条件下,每天溶解的钙壳相当于贝壳总重的2‰。相较于钙壳溶解,Ω文石改变对菲律宾蛤仔呼吸作用的影响更大,RC(μmol/(FWg·h))=0.27 × Ω文石+0.90 (n =12, r=0.82, p<0.01)。由于呼吸代谢决定了摄食等各种耗能行为的效率,因此本研究的结果表明,尽管菲律宾蛤仔可以通过摄食等自身调节机制来抵御造成钙壳溶解的环境胁迫,然而这一机制本身就可能受到酸化环境的不良影响。 相似文献
5.
挥发性卤代烃(volatilehalocarbon,VHCs)是大气中一类重要的臭氧层破坏者和环境污染物,海洋微藻释放是大气VHCs的重要来源,在调节全球气候中起着至关重要的作用。该研究在2个温度(T=20、25°C)和2个CO2分压(pCO2=395、790 mg/L)条件下,模拟研究了温度和pCO2升高对中肋骨条藻生长和3种VHCs (CHBr3、CHBr2Cl和CHBrCl2)释放量的影响。研究结果表明, pCO2=395 mg/L,T=25°C时,中肋骨条藻的生长情况最佳; pCO2=790 mg/L, T=20°C时,中肋骨条藻的生长情况最差。温度升高时,CHBr3、CHBr2Cl和CHBrCl2的平均浓度分别增加了10.55%、9.45%和12.18%;pCO2升高时, CHBr3和CHBrCl2的平均浓度分别降低了19.29%和30.... 相似文献
6.
通过实验室构建不同氮磷比条件下的酸化海水环境,培养麻痹性贝毒(paralytic shellfish toxin,PST)产毒藻微小亚历山大藻(Alexandrium minutum),采用藻细胞计数法、分光光度法、高效液相色谱-质谱法等分析方法,探讨了不同氮磷比条件下的酸化海水对微小亚历山大藻的生长、氮磷营养盐吸收、产毒等参数的影响。结果表明,在一定程度上,酸化环境对A.minutum的生长、PST的胞内累积和胞外释放有促进作用,且胞外培养液中PST含量增加的程度更高;同时,酸化海水促进胞内毒性较低的N-H类膝沟藻毒素(GTX2和GTX3)被氧化成毒性较高的N-OH类膝沟藻毒素(GTX1和GTX4),导致A.minutum的细胞毒性和培养液毒性增加。而海水中氮磷比的进一步升高,在一定程度上促进了微小亚历山大藻细胞毒素含量和毒性的增加,但并未促进其生长,且降低了藻细胞内的磷储量。 相似文献
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8.
《中国海洋大学学报(自然科学版)》2020,(5)
本文选取东海原甲藻和米氏凯伦藻,以氨氮(NH_4-N)为氮源,通过增加pCO_2(800和1 500μatm)改变海水的酸化程度,研究海洋酸化对东海原甲藻和米氏凯伦藻生长以及抗氧化生物酶活性的影响。研究结果表明,海洋酸化对东海原甲藻和米氏凯伦藻的生长均有抑制作用,两种藻的生长速率在酸化条件下均低于正常海水条件。东海原甲藻和米氏凯伦藻的最大氮吸收速率及其与半饱和常数的比值(V_(max)/K_s比率)均随着酸化程度的加深而降低,表明酸化抑制了浮游植物对NH_4-N的吸收。东海原甲藻在三个实验条件下的V_(max)/K_s比率均高于米氏凯伦藻,表明东海原甲藻比米氏凯伦藻有更强的环境适应性。海洋酸化诱导了东海原甲藻和米氏凯伦藻的活性氧(ROS)升高,随着酸化程度加深,抗氧化生物酶—超氧化歧化酶(SOD)和过氧化氢酶(CAT)活性升高,这说明,海洋酸化对两种甲藻生长的抑制,通过抗氧化酶的活性变化在生理层面对外界环境作出响应,与生长和营养盐吸收过程相对应。 相似文献
9.
人类活动引起的营养物质输入导致大亚湾出现海水富营养化、赤潮频发和生物多样性下降等生态问题。为探究陆源输入影响下大亚湾湾顶淡澳河输入对湾内浮游植物粒级结构和种类组成的影响, 2016年10月在大亚湾进行了原位观测和培养试验。原位观测结果显示, 淡澳河口的总溶解态氮、磷浓度分别达到85.3μmol·L-1和1.5μmol·L-1。加富培养试验结果表明, 淡澳河河口水加富对总叶绿素a (Chl a)和总浮游植物丰度有显著促进作用, 并导致浮游植物粒级结构由小粒级Chl a (0.7~20μm)占主导; 浮游植物丰度中甲藻比例升高, 主要种类为锥状斯氏藻(Scrippsiella trochoidea)和原甲藻(Prorocentrum spp.)。同样, 尿素加富也促进了浮游植物群落中小粒级Chl a和甲藻的比例增加, 且主要甲藻种类与河口水加富结果一致。无机氮、磷同时加富促进了总Chl a和浮游植物总丰度增加, 而对浮游植物粒级结构和甲藻丰度则没有明显影响。对照河口水和氮、磷营养盐加富试验结果, 说明河口水携带的溶解性有机氮源可能是导致大亚湾浮游植物群落小型化, 促进甲藻生长的关键营养盐形态, 其携带的无机氮、磷同时促进总浮游植物丰度增加。本研究结果表明有机形态营养组分对大亚湾富营养化和有害藻华可能产生重要影响。 相似文献
10.
以无性繁殖系为材料,开展了缘管浒苔和羽藻对NO3-,NH4+和PO43-的吸收动力学、生长动力学研究。吸收动力学研究结果表明缘管浒苔和羽藻对NO3- 和PO43-的吸收方式为主动运输,对NH4+的吸收方式为被动扩散。缘管浒苔对NO3-的最大吸收速率(Vmax)、对NH4+的吸收斜率都大于羽藻,说明缘管浒苔对高浓度的NO3-和NH4+具有更强的吸收能力。缘管浒苔吸收NO3-和NH4+的a值远大于羽藻,说明在低营养盐浓度时,缘管浒苔对NO3-和NH4+的亲和力更强。在PO43-的吸收中,羽藻的最大吸收速率(Vmax)远大于缘管浒苔,说明羽藻对高浓度PO43-的吸收能力更强,但缘管浒苔的a值远大于羽藻,说明前者在低营养盐浓度时PO43-的亲和力更强。生长动力学研究结果表明,硝酸氮是促进两种海藻快速生长的最适宜氮源形式,氨氮更易促进藻体叶绿素的积累。在相同氮营养条件下,羽藻表现出比缘管浒苔更强的生长优势。 相似文献
11.
Sub-Lethal Effects of Elevated Concentration of CO<Subscript>2</Subscript> on Planktonic Copepods and Sea Urchins 总被引：2，自引：0，他引：2
Data concerning the effects of high CO2 concentrations on marine organisms are essential for both predicting future impacts of the increasing atmospheric CO2 concentration and assessing the effects of deep-sea CO2sequestration. Here we review our recent studies evaluating the effects of elevated CO2 concentrations in seawater on the mortality and egg production of the marine planktonic copepod, Acartia steueri, and on the fertilization rate and larval morphology of sea urchin embryos, Hemicentrotus pulcherrimus and Echinometra mathaei. Under conditions of +10,000 ppm CO2 in seawater (pH 6.8), the egg production rates of copepods decreased significantly. The survival rates of adult copepods
were not affected when reared under increased CO2 for 8 days, however longer exposure times could have revealed toxic effects of elevated CO2 concentrations. The fertilization rate of sea urchin eggs of both species decreased with increasing CO2 concentration. Furthermore, the size of pluteus larvae decreased with increasing CO2 concentration and malformed skeletogenesis was observed in both larvae. This suggests that calcification is affected by elevated
CO2 in the seawater. From these results, we conclude that increased CO2 concentration in seawater will chronically affect several marine organisms and we discuss the effects of increased CO2 on the marine carbon cycle and marine ecosystem.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
根据2018年7月、11月和2019年1月、4月对广东考洲洋牡蛎养殖海域进行4个季节调查获得的pH、溶解无机碳(DIC)、水温、盐度、溶解氧(DO)及叶绿素a(Chla)等数据,估算该区域表层海水溶解无机碳体系各分量的浓度、初级生产力(PP)、表层海水CO2分压[p(CO2)]和海-气界面CO2交换通量(FCO2),分析牡蛎养殖活动对养殖区碳循环的影响。结果表明:牡蛎养殖区表层海水中Chla、DIC、HCO3–和PP显著低于非养殖区;养殖淡季表层海水中pH、DO、DIC、HCO3–、和CO32–显著大于养殖旺季,养殖旺季的p(CO2)和FCO2显著大于养殖淡季。牡蛎养殖区表层海水夏季、秋季、冬季和春季的海-气界面CO2交换通量FCO2平均值分别是(42.04±9.56)、(276.14±52.55)、(–11.59±18.15)和(–13.02±6.71)mmol/(m2·d),冬季各站位FCO2值离散度较大,其中位数是–10.73mmol/(m2·d)。在全年尺度,表层海水p(CO2)及FCO2与水温呈显著正相关,与盐度呈显著负相关。在非养殖区,浮游植物光合作用可能对影响表层海水p(CO2)及FCO2起主导作用。养殖牡蛎钙化、呼吸作用等生理因素释放的CO2对表层海水p(CO2)及FCO2未产生显著影响。考洲洋养殖海域养殖旺季为CO2的源,养殖淡季整体为CO2的弱汇。 相似文献
13.
Atsushi Ishimatsu Takashi Kikkawa Masahiro Hayashi Kyoung-Seon Lee Jun Kita 《Journal of Oceanography》2004,60(4):731-741
CO2-enriched seawater was far more toxic to eggs and larvae of a marine fish, silver seabream, Pagrus major, than HCl-acidified seawater when tested at the same seawater pH. Data on the effects of acidified seawater can therefore
not be used to estimate the toxicity of CO2, as has been done in earlier studies. Ontogenetic changes in CO2 tolerance of two marine bony fishes (Pag. major and Japanese sillago, Sillago japonica) showed a similar, characteristic pattern: the cleavage and juvenile stages were most susceptible, whereas the preflexion
and flexion stages were much more tolerant to CO2. Adult Japanese amberjack, Seriola quinqueradiata, and bastard halibut, Paralichthys olivaceus, died within 8 and 48 h, respectively, during exposure to seawater equilibrated with 5% CO2. Only 20% of a cartilaginous fish, starspotted smooth-hound, Mustelus manazo, died at 7% CO2 within 72 h. Arterial pH initially decreased but completely recovered within 1-24 h for Ser. quinqueradiata and Par. olivaceus at 1 and 3% CO2, but the recovery was slower and complete only at 1% for M. manazo. During exposure to 5% CO2, Par. olivaceus died after arterial pH had been completely restored. Exposure to 5% CO2 rapidly depressed the cardiac output of Ser. quinqueradiata, while 1% CO2 had no effect. Both levels of ambient CO2 had no effect on blood O2 levels. We tentatively conclude that cardiac failure is important in the mechanisms by which CO2 kills fish. High CO2 levels near injection points during CO2 ocean sequestration are likely to have acute deleterious effects on both larvae and adults of marine fishes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
从上行控制角度，通过野外采样和围隔培养实验，研究了水母的代谢及分解过程对水体环境中pH、溶解氧、营养盐组成的影响，以及该过程中浮游植物的变化。实验结果表明，沙海蜇在代谢过程中短时间内会大量消耗水体中的溶解氧（dissolved oxygen，DO），使水体出现低氧和轻度酸化。代谢过程释放出大量营养盐，使水体中的溶解无机氮（dissolved inorganic nitrogen，DIN）浓度在24h内增加为原来的12倍，溶解无机磷（dissolved inorganic phosphorus，DIP）浓度增加了40多倍，进而引起水体中叶绿素a（chlorophyll a，chl a）浓度的增加。沙海蜇的分解过程使水体表现出明显的低氧（缺氧）和酸化现象。沙海蜇生物量越大，分解时间越长，对水体的改变程度越明显，此外，还释放出大量的营养盐并改变原有的营养盐结构，可以刺激甲藻和绿藻的生长，甚至可能引发藻华。 相似文献
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水-气平衡法被广泛地应用于海水CO2分压（partial pressure,pCO2）的测定。该方法采用水-气平衡器,使海水与平衡器上部顶空中的空气进行CO2交换,达到平衡后测定该顶空空气中CO2的浓度,再换算成海水pCO2。水-气平衡器是海水pCO2测量仪器的关键部件,其性能在很大程度上决定所获得的pCO2数据的准确度和可靠性。本文介绍了水-气平衡器的平衡原理、平衡器时间常数的测量方法及影响因素,归纳了现有的4种用于海水pCO2测量的水-气平衡器即喷淋式、鼓泡式、层流式及混合式平衡器的结构与特点,着重介绍了两种新型的水 气平衡器即基于射流器的鼓泡式平衡器和基于球形降膜的层流式平衡器,比较了不同水-气平衡器的尺寸、运行参数及时间常数,分析了设计和应用水-气平衡器时需考虑的因素。本文可为使用水-气平衡器测定海水pCO2的技术人员提供技术参考。 相似文献
16.
It widely thought that ocean acidification processes that caused by atmospheric CO2 increase and accordingly lower seawater pH conditions might cause serious harm to marine food webs in certain ecosystems in the near future. Little is known about how marine fishes respond to reduced pH conditions. We investigated the effects of CO2 conditions on the growth of olive flounder (Paralichthys olivaceus) larvae. Newly hatched larvae were reared at three different levels of pCO2 (574, 988 and 1297 µatm) in temperature-controlled (21 ± 0.5°C) water tanks for four weeks until metamorphosis. The experiment was repeated three times in May, June, and July 2011, and body lengths and weights were measured at the completion of each experiment. The results indicated that the body length and weight of flounder larvae significantly increased with increasing CO2 concentrations (P < 0.05). A higher daily growth rate during the early larval stage (hatching to 14 days) was found among the larvae reared in low pCO2 conditions, while a significantly lower growth rate was found among larvae in higher pCO2 water conditions. On the other hand, in the late larval stage (18 days after hatching to metamorphosis), the daily growth rate of larvae was much higher in high CO2 water. Bone density of larvae, however, decreased with increasing CO2 concentration in the water
相似文献17.
Stable carbon isotope distribution of particulate organic matter in the ocean: a model study 总被引：4，自引：0，他引：4
Matthias Hofmann Dieter A. Wolf-Gladrow Taro Takahashi Steward C. Sutherland Katharina D. Six Ernst Maier-Reimer 《Marine Chemistry》2000,72(2-4)
The stable carbon isotopic composition of particulate organic matter in the ocean, δ13CPOC, shows characteristic spatial variations with high values in low latitudes and low values in high latitudes. The lowest δ13CPOC values (−32‰ to −35‰) have been reported in the Southern Ocean, whereas in arctic and subarctic regions δ13CPOC values do not drop below −27‰. This interhemispheric asymmetry is still unexplained. Global gradients in δ13CPOC are much greater than in δ13CDIC, suggesting that variations in isotopic fractionation during organic matter production are primarily responsible for the observed range in δ13CPOC. Understanding the factors that control isotope variability is a prerequisite when applying δ13CPOC to the study of marine carbon biogeochemistry. The present model study attempts to reproduce the δ13CPOC distribution pattern in the ocean. The three-dimensional (3D) Hamburg Model of the Oceanic Carbon Cycle version 3.1 (HAMOCC3.1) was combined with two different parametrizations of the biological fractionation of stable carbon isotopes. In the first parametrization, it is assumed that the isotopic fractionation between CO2 in seawater and the organic material produced by algae, P, is a function of the ambient CO2 concentration. The two parameters of this function are derived from observations and are not based on an assumption of any specific mechanism. Thus, this parametrization is purely empirical. The second parametrization is based on fractionation models for microalgae. It is supported by several laboratory experiments. Here the fractionation, P, depends on the CO2 concentration in seawater and on the (instantaneous) growth rates, μi, of the phytoplankton. In the Atlantic Ocean, where most field data are available, both parametrizations reproduce the latitudinal variability of the mean δ13CPOC distribution. The interhemispheric asymmetry of δ13CPOC can mostly be attributed to the interhemispheric asymmetry of CO2 concentration in the water. However, the strong seasonal variations of δ13CPOC as reported by several authors, can only be explained by a growth rate-dependent fractionation, which reflects variations in the cellular carbon demand. 相似文献
18.
We investigated the effects of seawater acidification induced by ocean CO2 sequestration on bathypelagic prokaryotes. We simulated acidification conditions by bubbling high-CO2 air or adding chemical buffer solutions to seawater samples in order to examine changes in total cell counts, heterotrophic
production rate, direct viable cell count, and relative abundance of Bacteria and Archaea. Considerable suppression of prokaryotic activities was observed at pH 7.0 or lower, especially in samples enriched with
organic matter. The relative abundance of Archaea increased with increasing CO2 concentration. We found that seawater acidification can potentially alter heterotrophic activities and community structure
of bathypelagic prokaryotes. 相似文献
19.
海洋浮游动物可以对因二氧化碳浓度升高导致的海水酸化做出敏感的响应,然而关于海水酸化对其生理机能的研究却较少。因此,我们研究了暴露于不同二氧化碳浓度（0.08,0.20,0.50 and 1.00%）的酸化条件下中华哲水蚤主要抗氧化酶以及2种解毒酶的活性变化情况。结果表明,暴露于酸化海水中的中华哲水蚤的GPx酶活性显著高于对照组,然而,其它抗氧化组分,包括GST、SOD活性,GSH水平和GSH/GSSG比值均被显著抑制。中华哲水蚤的ATPase活性被海水酸化显著刺激,而AchE活性却显著被抑制。此外,主成分分析结果表明,各指标变化的75.93%可以用第一和第二主成分解释。因二氧化碳浓度升高导致的海水酸化可以通过影响桡足类体内一些酶类的活性来影响其新陈代谢及存活。在未来的研究工作中,需要对海水酸化和其它环境因素的协同作用对桡足类的影响作进一步研究。 相似文献