海水酸化及升温对刺参生长及能量收支的影响

以东亚浅海生态系统中的关键种——刺参(Apostichopus japonicus)为实验对象,研究了CO₂驱动的海水酸化及升温对其生长及能量收支的影响。实验设置对照组(大连近海水温, pCO₂ 400μatm)、升温组(大连近海水温+3℃, pCO₂ 400μatm)、酸化组(大连近海水温, pCO₂ 1100μatm)和酸化升温组(大连近海水温+3℃,pCO₂ 1100μatm)。结果表明:与对照组相比,温度升高3℃对刺参的生长无显著影响;酸化组刺参的特定生长率最低,较对照组降低0.19%/d,个体体重的变异系数最大;酸化升温组刺参的终末体重和特定生长率与对照组相较无显著差异,但其摄食率和排粪率均显著高于对照组。升温组和酸化组的刺参能量的分配模式与对照组相比未发生明显改变,但酸化升温组刺参的能量分配模式发生显著变化,其粪便能所占摄食能的比例显著升高。研究表明,海水酸化抑制了刺参的生长但未改变其能量的分配,生长的降低主要取决于摄食减少;而海水酸化与温度升高的共同作用可能会通过...     

海洋酸化和全球变暖对贝类生理生态的影响研究进展

研究表明海洋酸化和全球变暖已严重威胁到海洋生态系统稳的定性及生物多样性。由于人类活动,大气中不断增加的CO2不仅造成全球气候异常,而且大量的CO2被海洋吸收,造成了海水中H+浓度增加,即海洋酸化(Ocean Acidification)。海洋酸化严重影响海洋生物的生存和繁衍,尤其是有壳类生物,如贝类,甲壳类,棘皮类等。主要影响方面包括生物的产卵受精,孵化,早期发育,钙化,酸碱调节,免疫功能,蛋白质合成,基因表达,摄食及能量代谢等一系列和生理相关的机能,进而对个体行为学,种群结构和海洋生态系统造成严重危害。目前,已有大量海洋酸化对海洋贝类的生理生态影响的报道,与此同时,全球变暖导致海洋温度升高伴随着海洋酸化同步发生。因此,为了更加准确地预测海洋生物应对全球气候变化的生理生态应答,越来越多的学者开始致力于研究温度和海洋酸化的复合胁迫对海洋生物交互影响作用。综述了近年来海洋酸化对贝类生理生态的影响,主要从个体早期发育、钙化、免疫、繁殖等方面做了系统的阐述,还对酸化和温度对贝类的复合环境胁迫效应也做了综合分析,以期为今后的海洋酸化研究提供基础理论。     

海洋酸化影响硅藻固碳相关基因表达的研究进展

由于人类活动导致的大气CO2浓度升高,将导致海水p H值下降,从而引起海洋酸化,改变海水碳酸盐系统,影响海洋生物的生长、发育、代谢、凋亡及钙化过程等。研究海洋酸化对藻类固碳途径(生物碳泵)的影响对了解和预测未来海洋碳泵的发展趋势具有重要意义,硅藻作为海洋初级生产力的主要生产者,研究海洋酸化影响其固碳过程的意义更大。尽管目前已对海洋酸化影响硅藻的生理生化过程有了较为深入的研究,但从基因表达水平上研究海洋酸化对硅藻固碳过程的影响还较少,本文对此领域做一概述。     

鱼类对海洋升温与酸化的响应

自工业革命以来,空气中人为排放CO₂量增加,引起温室效应,导致地球表面温度升高和海水升温;同时,由于海-气界面气体交换,大气中CO₂部分溶解于海洋,引起海洋酸化。海洋升温加快鱼体内生化反应和代谢速率,并通过影响生长、觅食和繁殖等生命过程中能量供给,间接影响到鱼类种群分布、群落结构及生态系统的功能。而海水酸化会干扰海洋鱼类仔稚鱼的感觉和行为,增加其被捕食率,并削弱其野外生存能力,可能威胁自然种群补给量。综述了海洋升温、海洋酸化及其两者共同作用对海洋鱼类的影响,为预测鱼类响应全球海洋环境变化的响应趋势提供相关依据。     

海洋酸化生态学研究进展

工业革命以来,人类排放的大量二氧化碳引起温室效应的同时,也被海洋吸收使得全球海洋出现了严重的酸化。海洋酸化及伴随的海水碳酸盐化学体系的变化对海洋生物产生深远的影响。以海洋酸化对钙化作用和光合作用的影响为重点,总结了近年来关于海洋酸化的研究,介绍了海洋中不同生态系统对海洋酸化的响应。一方面,海水中CO23-浓度和碳酸钙饱和度的降低对海洋钙化生物造成严重损害,生活在高纬的冷水珊瑚和翼足目等文石生产者是最早的受害者;贝类和棘皮动物在钙化早期对海洋酸化尤其敏感,其幼体存活率受到海洋酸化的严重制约。另一方面,CO2浓度的增加能促进海洋植物的光合作用和生长,增加初级生产力,改变浮游植物的群落组成。此外,海洋酸化可以促进固氮和脱氮作用同时削弱硝化作用,改变溶氧浓度分布和金属的生物可利用性,从而对海洋生物产生间接影响。海洋酸化对海洋生态系统的影响机制复杂,影响程度深远。为了能准确的评估海洋酸化的生态学效应,需要更全面深入的研究。     

蓬莱玉参早期发育的形态学观察

本研究对仿刺参(Apostichopus japonicus)的一个特殊品系蓬莱玉参产卵、受精及胚胎和幼体发育过程进行显微观察,并与普通仿刺参进行比较。在19~21℃水温下,蓬莱玉参受精卵分别在受精12 min和24 min后释放第一、二极体,1 h后卵裂成2细胞期,之后每30 min左右完成一次卵裂,6 h后进入囊胚期,19 h后发育成原肠胚;40 h后进入耳状幼体阶段,在其后侧臂的一端出现一个不规则形的石灰质骨片,并发现其位置与水体腔处于同一侧这一规律;5 d和8 d后发育为中耳状幼体和大耳状幼体,10 d后变态发育为樽形幼体,骨片由不规则状发育为齿轮状,并出现第二个石灰质骨片;12 d后发育为五触手,14 d后发育成稚参,40 d后发育为幼参。蓬莱玉参胚胎和幼体发育时序与当前已报道的仿刺参无显著差异,但从幼参开始蓬莱玉参通体始终为白色,而普通仿刺参在45日龄时体表局部出现色素,疣足处较为明显,60日龄幼体一半以上全身布满色素。蓬莱玉参因通体纯白色而受到了众多养殖企业和研究领域的关注,本文的结果为其今后的研究奠定了可靠的理论基础。     

全球气候变化下的海洋生物多样性

正当前人类社会发展改变了整个地球生态系统,地球历史进入了全新的人类世(Anthropocene)阶段(Steffen et al,2007)。人类活动对海洋生态系统及其生物多样性造成越来越显著的影响,尤以全球气候变化(global climate change)对海洋生物多样性的改变最为深刻,且影响面较广。全球气候变化主要表现在人类活动造成的化石燃料向大气排放过多的CO2而引起海水表层升温、海平面上升、降雨改变、海洋表层海水酸化、海流变化及紫外线辐射增强等一系列环境改变     

背瘤丽蚌稚蚌的生长与发育

利用显微技术连续观察了背瘤丽蚌(Lamprotula leai)稚蚌发育、行为、生长和壳型变化等重要生物学特征。结果表明,刚脱落的稚蚌平均壳长208.5μm,在水温23.9～32.8℃条件下,经过75 d生长发育,进入幼蚌阶段,此时幼蚌平均壳长10.12 mm。壳长(L)、壳高(H)与日龄(t)的关系分别为L=0.220 4 e0.051 2t(R2=0.993 5)和H=0.227 7 e0.041 8t(R2=0.994 2),壳高(H)与壳长(L)的关系为H=0.781 5 L0.814(R2=0.998 1)。以稚蚌行为特征变化为依据,将背瘤丽蚌稚蚌发育划分为爬行期和埋栖期,再以稚蚌壳形状变化为依据,将爬行期稚蚌发育分为稚蚌脱落期、背部平直期、壳顶突出期,反映了背瘤丽蚌稚蚌生长与发育过程的动态变化。     

刺参对浅海筏式贝类养殖系统的修复潜力

浅海筏式养殖滤食性贝类产生大量的粪便和假粪（总称生物沉积物）,对海水养殖环境产生一系列影响;而沉积食性海参能够有效清除颗粒有机物,在海水养殖系统中扮演“清道夫”的生态角色.为评估刺参在浅海筏式贝类养殖系统中的生物修复潜力,本文在不同季节现场研究了贝 参混养模式下刺参对贝类生物沉积物的摄食及生长和排泄特征.结果表明: 刺参能够在新设计的养殖设施中与滤食性贝类混养,最大生长率达0.34%·d^-1; 并可通过摄食有效清除贝类生物沉积物, 摄食率为0.1746 g·g^-1·d^-1（夏季,21.2 ℃）、0.0989 g·g^-1·d^-1（秋季,19.2 ℃）和0.0050 g·g^-1·d^-1（冬季,7.7 ℃）;刺参主要通过排泄溶解形态的NH₄⁺N和PO₄^3- -P来促进沉积物中营养盐的再生,其排泄率也呈现明显的季节变化.基于现场试验数据,估算了刺参在桑沟湾的生物修复潜力, 刺参与贝类混养可摄食4.5～159.6 kg·hm^-2·d^-1生物沉积物、排泄1 382.5～3 678.1 mmol·hm^-2·d^-1NH₄⁺ -N及74.6～335.7 mmol·hm^-2·d^-1PO₄^3--P.表明刺参对浅海筏式贝类养殖系统具有较大的生物修复潜力,贝-参混养模式不仅能够取得较大的生态效益,而且能显著增加养殖生产的经济效益.     

海洋酸化对海洋无脊椎动物的影响研究进展

人源二氧化碳(CO2)的大量排放,导致空气中CO2浓度越来越高,其中大约1/4至1/3被海洋吸收。过多CO2在海水中的溶解,除引起海水p H值降低外,还导致海水中碳酸盐平衡体系的变化,即"海洋酸化"现象。很多海洋无脊椎动物不但在海洋生态系统中发挥重要作用,还是重要的水产养殖种,因此具有重要的生态与经济价值。由于海洋无脊椎动物的生活史在海水中完成,因此海洋环境的变化极易对其造成影响。大量研究已证实海洋酸化能对多种海洋无脊椎动物的受精、发育、生物钙化、基因表达等生命活动产生显著影响。综述了近年来海洋酸化对海洋无脊椎动物影响研究的相关报道,归纳了其对海洋无脊椎动物不同生命活动的影响,分析了其生态学效应,探讨了现有研究在方法创新、内容拓展以及机理分析等方面存在的局限与不足,并展望了海洋酸化对海洋无脊椎动物影响研究的发展方向。     

Unshelled abalone and corrupted urchins: development of marine calcifiers in a changing ocean

The most fragile skeletons produced by benthic marine calcifiers are those that larvae and juveniles make to support their bodies. Ocean warming, acidification, decreased carbonate saturation and their interactive effects are likely to impair skeletogenesis. Failure to produce skeleton in a changing ocean has negative implications for a diversity of marine species. We examined the interactive effects of warming and acidification on an abalone (Haliotis coccoradiata) and a sea urchin (Heliocidaris erythrogramma) reared from fertilization in temperature and pH/pCO(2) treatments in a climatically and regionally relevant setting. Exposure of ectodermal (abalone) and mesodermal (echinoid) calcifying systems to warming (+2°C to 4°C) and acidification (pH 7.6-7.8) resulted in unshelled larvae and abnormal juveniles. Haliotis development was most sensitive with no interaction between stressors. For Heliocidaris, the percentage of normal juveniles decreased in response to both stressors, although a +2°C warming diminished the negative effect of low pH. The number of spines produced decreased with increasing acidification/pCO(2), and the interactive effect between stressors indicated that a +2°C warming reduced the negative effects of low pH. At +4°C, the developmental thermal tolerance was breached. Our results show that projected near-future climate change will have deleterious effects on development with differences in vulnerability in the two species.     

Temperature and CO2 additively regulate physiology,morphology and genomic responses of larval sea urchins,Strongylocentrotus purpuratus

Ocean warming and ocean acidification, both consequences of anthropogenic production of CO₂, will combine to influence the physiological performance of many species in the marine environment. In this study, we used an integrative approach to forecast the impact of future ocean conditions on larval purple sea urchins (Strongylocentrotus purpuratus) from the northeast Pacific Ocean. In laboratory experiments that simulated ocean warming and ocean acidification, we examined larval development, skeletal growth, metabolism and patterns of gene expression using an orthogonal comparison of two temperature (13°C and 18°C) and pCO₂ (400 and 1100 μatm) conditions. Simultaneous exposure to increased temperature and pCO₂ significantly reduced larval metabolism and triggered a widespread downregulation of histone encoding genes. pCO₂ but not temperature impaired skeletal growth and reduced the expression of a major spicule matrix protein, suggesting that skeletal growth will not be further inhibited by ocean warming. Importantly, shifts in skeletal growth were not associated with developmental delay. Collectively, our results indicate that global change variables will have additive effects that exceed thresholds for optimized physiological performance in this keystone marine species.     

Effects of ocean warming and acidification on survival,growth and skeletal development in the early benthic juvenile sea urchin (Heliocidaris erythrogramma)

Co‐occurring ocean warming, acidification and reduced carbonate mineral saturation have significant impacts on marine biota, especially calcifying organisms. The effects of these stressors on development and calcification in newly metamorphosed juveniles (ca. 0.5 mm test diameter) of the intertidal sea urchin Heliocidaris erythrogramma, an ecologically important species in temperate Australia, were investigated in context with present and projected future conditions. Habitat temperature and pH/pCO₂ were documented to place experiments in a biologically and ecologically relevant context. These parameters fluctuated diurnally up to 10 °C and 0.45 pH units. The juveniles were exposed to three temperature (21, 23 and 25 °C) and four pH (8.1, 7.8, 7.6 and 7.4) treatments in all combinations, representing ambient sea surface conditions (21 °C, pH 8.1; pCO₂ 397; Ω_Ca 4.7; Ω_Ar 3.1), near‐future projected change (+2–4 °C, ?0.3–0.5 pH units; pCO₂ 400–1820; Ω_Ca 5.0–1.6; Ω_Ar 3.3–1.1), and extreme conditions experienced at low tide (+4 °C, ?0.3–0.7 pH units; pCO₂ 2850–2967; Ω_Ca 1.1–1.0; Ω_Ar 0.7–0.6). The lowest pH treatment (pH 7.4) was used to assess tolerance levels. Juvenile survival and test growth were resilient to current and near‐future warming and acidification. Spine development, however, was negatively affected by near‐future increased temperature (+2–4 °C) and extreme acidification (pH 7.4), with a complex interaction between stressors. Near‐future warming was the more significant stressor. Spine tips were dissolved in the pH 7.4 treatments. Adaptation to fluctuating temperature‐pH conditions in the intertidal may convey resilience to juvenile H. erythrogramma to changing ocean conditions, however, ocean warming and acidification may shift baseline intertidal temperature and pH/pCO₂ to levels that exceed tolerance limits.     

CO2 induced seawater acidification impacts sea urchin larval development I: elevated metabolic rates decrease scope for growth and induce developmental delay

Anthropogenic CO(2) emissions are acidifying the world's oceans. A growing body of evidence is showing that ocean acidification impacts growth and developmental rates of marine invertebrates. Here we test the impact of elevated seawater pCO(2) (129 Pa, 1271 μatm) on early development, larval metabolic and feeding rates in a marine model organism, the sea urchin Strongylocentrotus purpuratus. Growth and development was assessed by measuring total body length, body rod length, postoral rod length and posterolateral rod length. Comparing these parameters between treatments suggests that larvae suffer from a developmental delay (by ca. 8%) rather than from the previously postulated reductions in size at comparable developmental stages. Further, we found maximum increases in respiration rates of +100% under elevated pCO(2), while body length corrected feeding rates did not differ between larvae from both treatments. Calculating scope for growth illustrates that larvae raised under high pCO(2) spent an average of 39 to 45% of the available energy for somatic growth, while control larvae could allocate between 78 and 80% of the available energy into growth processes. Our results highlight the importance of defining a standard frame of reference when comparing a given parameter between treatments, as observed differences can be easily due to comparison of different larval ages with their specific set of biological characters.     

Size matters: plasticity in metabolic scaling shows body-size may modulate responses to climate change

Variability in metabolic scaling in animals, the relationship between metabolic rate (R) and body mass (M), has been a source of debate and controversy for decades. R is proportional to M^b, the precise value of b much debated, but historically considered equal in all organisms. Recent metabolic theory, however, predicts b to vary among species with ecology and metabolic level, and may also vary within species under different abiotic conditions. Under climate change, most species will experience increased temperatures, and marine organisms will experience the additional stressor of decreased seawater pH (‘ocean acidification’). Responses to these environmental changes are modulated by myriad species-specific factors. Body-size is a fundamental biological parameter, but its modulating role is relatively unexplored. Here, we show that changes to metabolic scaling reveal asymmetric responses to stressors across body-size ranges; b is systematically decreased under increasing temperature in three grazing molluscs, indicating smaller individuals were more responsive to warming. Larger individuals were, however, more responsive to reduced seawater pH in low temperatures. These alterations to the allometry of metabolism highlight abiotic control of metabolic scaling, and indicate that responses to climate warming and ocean acidification may be modulated by body-size.     

海洋酸化条件下Cd2+和Hg2+对斧文蛤幼贝急性毒性效应

为研究在海洋酸化条件下重金属污染物对滩涂贝类的影响,采用半静态急性毒性实验的研究方法,利用海洋酸化人工模拟系统,分析了不同酸化条件下(对照组pH 8.20、酸化组pH分别为7.80、7.60和7.40)Cd2+和Hg2+对斧文蛤(Meretrix lamarckii)幼贝急性毒性效应的影响。实验结果表明:在实验设定的海洋酸化范围内,单一的海洋酸化对斧文蛤幼贝的存活没有显著性影响,但海洋酸化显著增强了Cd2+和Hg2+的急性毒性。与对照组相比,酸化组Cd2+和Hg2+的毒性随着酸化程度的加剧而呈现出逐渐增强的趋势; Cd2+和Hg2+均在pH 7.40时对斧文蛤的毒性最强,其96h半致死(96h LC50)浓度分别为4.068 mg/L(Cd2+)和10.332 mg/L(Hg2+),明显低于pH 8.20、7.80和7.60时其对斧文蛤幼贝的96h LC50浓度(其值分别为Cd2+ 6.458、5.947、4.728 mg/L和Hg2+ 12.027、11.169、10.595 mg/L)。研究有助于丰富海洋酸化与重金属毒理作用在海洋贝类中的研究内容,为斧文蛤资源恢复和海洋环境保护提供科学依据。     

Meta‐analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming

Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta‐analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life‐history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single‐stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible.     

Adjustments in fatty acid composition is a mechanism that can explain resilience to marine heatwaves and future ocean conditions in the habitat‐forming seaweed Phyllospora comosa (Labillardière) C.Agardh

Marine heatwaves are extreme events that can have profound and lasting impacts on marine species. Field observations have shown seaweeds to be highly susceptible to marine heatwaves, but the physiological drivers of this susceptibility are poorly understood. Furthermore, the effects of marine heatwaves in conjunction with ocean warming and acidification are yet to be investigated. To address this knowledge gap, we conducted a laboratory culture experiment in which we tested the growth and physiological responses of Phyllospora comosa juveniles from the southern extent of its range (43–31°S) to marine heatwaves, ocean warming and acidification. We used a ‘collapsed factorial design’ in which marine heatwaves were superimposed on current (today's pH and temperature) and future (pH and temperature projected by 2100) ocean conditions. Responses were tested both during the heatwaves, and after a 7‐day recovery period. Heatwaves reduced net photosynthetic rates in both current and future conditions, while respiration rates were elevated under heatwaves in the current conditions only. Following the recovery period, there was little evidence of heatwaves having lasting negative effects on growth, photosynthesis or respiration. Exposure to heatwaves, future ocean conditions or both caused an increase in the degree of saturation of fatty acids. This adjustment may have counteracted negative effects of elevated temperatures by decreasing membrane fluidity, which increases at higher temperatures. Furthermore, P. comosa appeared to down‐regulate the energetically expensive carbon dioxide concentrating mechanism in the future conditions with a reduction in δ¹³C values detected in these treatments. Any saved energy arising from this down‐regulation was not invested in growth and was likely invested in the adjustment of fatty acid composition. This adjustment is a mechanism by which P. comosa and other seaweeds may tolerate the negative effects of ocean warming and marine heatwaves through benefits arising from ocean acidification.