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1.
Riccardo Rodolfo‐Metalpa Chiara Lombardi Silvia Cocito Jason M. Hall‐Spencer Maria Cristina Gambi 《Marine Ecology》2010,31(3):447-456
There are serious concerns that ocean acidification will combine with the effects of global warming to cause major shifts in marine ecosystems, but there is a lack of field data on the combined ecological effects of these changes due to the difficulty of creating large‐scale, long‐term exposures to elevated CO2 and temperature. Here we report the first coastal transplant experiment designed to investigate the effects of naturally acidified seawater on the rates of net calcification and dissolution of the branched calcitic bryozoan Myriapora truncata (Pallas, 1766). Colonies were transplanted to normal (pH 8.1), high (mean pH 7.66, minimum value 7.33) and extremely high CO2 conditions (mean pH 7.43, minimum value 6.83) at gas vents off Ischia Island (Tyrrhenian Sea, Italy). The net calcification rates of live colonies and the dissolution rates of dead colonies were estimated by weighing after 45 days (May–June 2008) and after 128 days (July–October) to examine the hypothesis that high CO2 levels affect bryozoan growth and survival differently during moderate and warm water conditions. In the first observation period, seawater temperatures ranged from 19 to 24 °C; dead M. truncata colonies dissolved at high CO2 levels (pH 7.66), whereas live specimens maintained the same net calcification rate as those growing at normal pH. In extremely high CO2 conditions (mean pH 7.43), the live bryozoans calcified significantly less than those at normal pH. Therefore, established colonies of M. truncata seem well able to withstand the levels of ocean acidification predicted in the next 200 years, possibly because the soft tissues protect the skeleton from an external decrease in pH. However, during the second period of observation a prolonged period of high seawater temperatures (25–28 °C) halted calcification both in controls and at high CO2, and all transplants died when high temperatures were combined with extremely high CO2 levels. Clearly, attempts to predict the future response of organisms to ocean acidification need to consider the effects of concurrent changes such as the Mediterranean trend for increased summer temperatures in surface waters. Although M. truncata was resilient to short‐term exposure to high levels of ocean acidification at normal temperatures, our field transplants showed that its ability to calcify at higher temperatures was compromised, adding it to the growing list of species now potentially threatened by global warming. 相似文献
2.
B. Velimirov 《Marine Ecology》1980,1(2):155-168
Abstract. An experiment to test C have's hypothesis on temperature dependent MgCO3 concentrations in marine calcareous skeletons was undertaken by transplanting colonies of Heliopora coerulea. The corals were transferred from a shallow lagoon with high average temperatures to the outer bottom of a fringing reef, 16 m depth, with low average temperatures. Against expectation, a statistically significant increase of average mol % concentrations from 0.48 to 0.54 % for upper growth regions and from 0.49 to 0.62% for lower growth regions was obtained. Temperature records during the experimentation period and the above data indicate that the mol% MgCO3 concentration in the skeleton of living Heliopora colonies increases when transplanted to an environment with a lower temperature average than that of their original growth site, and with seasonal temperature fluctuations which are smaller in the experimental site than in the control site. Temperature fluctuations at the control site were up to 2.5 times greater than at the experimental site for most of the observation months. This supports the conclusion that the parameters a) minimum temperature and b) temperature stability of the environment are essential for the incorporation of Mg into the carbonate skeleton matrix of marine organisms. Within this study the results of a quantitative chemical analysis of the carbonate skeleton of H. coerulea are presented and growth data of transplanted colonies compared with those from the control site. 相似文献
3.
Three colonies of the erect, robust branching, cheilostome bryozoan Adeonellopsis sp. were collected from Doubtful Sound, New Zealand, to investigate within‐colony variation in carbonate mineralogy. One‐hundred‐and‐twenty‐one sections from 9 branches were found to contain mostly aragonite, with calcite ranging from 1.1 to 7.3 wt% (mean ± SD = 2.4 ± 1.2 wt%, n = 120). The magnesium (Mg) content in calcite ranged from 5.3 to 13.1 wt% magnesium carbonate (8.8 ± 1.0 wt% MgCO3; n = 120). Calcite content decreased with increasing age proximally along the branch, indicating that secondary thickening is achieved with aragonite. In contrast, an oscillating trend in Mg content along branches suggests that seasonal or interannual environmental parameters may influence this geochemical parameter. Mineralogical variability highlights the need for multiple samples from the same colony to be measured when determining quantitative carbonate mineralogy in bryozoans. Bimineralic bryozoans such as Adeonellopsis sp. may have lower preservation potential than monomineralic bryozoans, and consequently may not survive diagenesis to become fossils. Bimineralic species may also be more vulnerable to dissolution pressure and possible ocean acidification than monomineralic calcitic taxa. 相似文献
4.
C. E. Lazareth E. Vander Putten L. Andr F. Dehairs 《Estuarine, Coastal and Shelf Science》2003,57(5-6):1103-1114
The shell chemistry of Isognomon ephippium from three Kenyan sites (Tudor, Gazi and Mida) has been investigated to determine whether these bivalves record environmental parameters. The Mg, Sr, Ba and Mn distributions in the calcite shell layer were determined by using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). In addition, whole-shell analyses were made to evaluate inter-site differences. While some variability is observed for mean Mg concentrations, the mean Sr concentrations were similar for the three sites. The decreasing mean Ba and Mn concentrations, following the order Tudor > Gazi > Mida, are related to distinct regimes of freshwater and nutrient supply. The Mg profiles, determined by LA-ICP-MS, displayed a close to regular sinusoidal pattern, depending on specimen and sample site. For the Tudor shells, an arbitrary fitting of the Mg profiles to sea-surface temperature (SST) variations emphasised the good relationship between these two parameters and allowed for the calculation of mean annual growth rates. In most of the shells, Sr partly co-varied with Mg and Ba, highlighting the complexity of Sr incorporation. The Ba and Mn profiles of the Tudor shells displayed several sharp maxima. With a time scale deduced from the Mg–SST relationship, the Ba and Mn maxima of the Tudor shells closely followed periods of maximal rainfall associated with the southeast monsoon. These Ba and Mn maxima were tentatively associated with algal bloom events known to succeed these periods of high rainfall. The less clearly marked seasonality of the Ba and Mn maxima for the Gazi and Mida specimens is thought to result from weaker seasonal variations in nutrient supply and reduced nutrients inputs. This study highlights the potential of I. ephippium as a recorder of spatio-temporal environmental variations in tropical coastal ecosystems. 相似文献
5.
通过电镜、电子探针和X射线等项分析,对东海沉积物中的有孔虫、腹足类、双壳类、苔藓、珊瑚、海胆等骨屑进行了矿物学研究,确定了矿物成分与生物属种的关系,并基于有孔虫壳体化学成分将壳体分为均质壳和异质壳,生物碳酸盐中镁主要富集在方解石及镁方解石中,锶在方解石和镁方解石中的分配系数(D)相似,为0.11—0.14;在文石质骨屑中D=1.09-1.20。碳氧同位素组成与生物属种有明显关系。据一些有孔虫壳体氧同位素偏差值计算的水温来看,本次测定的有孔虫属种的骨屑不能作为理想的骨屑温度计。 相似文献
6.
The shells ofMytilus edulis in the Tay estuary, Scotland, show mean aragonite contents of 55%, but in one zone the average aragonite proportion is only
45%. Comparison with data forMytilus edulis from other regions indicates the temperature and salinity are not the only significant determinants of the aragonite/calcite
ratio. Elimination of other variables suggests that sewage discharges may influence the mineralogy of the shell secreted byMytilus edulis in the relatively nutrient-enriched areas. 相似文献
7.
Federica Costantini Marco Taviani Alessandro Remia Eleonora Pintus Patrick J. Schembri Marco Abbiati 《Marine Ecology》2010,31(2):261-269
The precious red coral Corallium rubrum (L., 1758) lives in the Mediterranean Sea and adjacent Eastern Atlantic Ocean on subtidal hard substrates. Corallium rubrum is a long‐lived gorgonian coral that has been commercially harvested since ancient times for its red axial calcitic skeleton and which, at present, is thought to be in decline because of overexploitation. The depth distribution of C. rubrum is known to range from c. 15 to 300 m. Recently, live red coral colonies have been observed in the Strait of Sicily at depths of c. 600–800 m. This record sheds new light on the ecology, biology, biogeography and dispersal mechanism of this species and calls for an evaluation of the genetic divergence occurring among highly fragmented populations. A genetic characterization of the deep‐sea red coral colonies has been done to investigate biological processes affecting dispersal and population resilience, as well as to define the level of isolation/differentiation between shallow‐ and deep‐water populations of the Mediterranean Sea. Deep‐water C. rubrum colonies were collected at two sites (south of Malta and off Linosa Island) during the cruise MARCOS of the R/V Urania. Collected colonies were genotyped using a set of molecular markers differing in their level of polymorphism. Microsatellites have been confirmed to be useful markers for individual genotyping of C. rubrum colonies. ITS‐1 and mtMSH sequences of deep‐water red coral colonies were found to be different from those found in shallow water colonies, suggesting the possible occurrence of genetic isolation among shallow‐ and deep‐water populations. These findings suggest that genetic diversity of red coral over its actual range of depth distribution is shaped by complex interactions among geological, historical, biological and ecological processes. 相似文献
8.
The distribution coefficient (λMg) of Mg2+ ions between calcite and solution was found to be 0.012 ± 0.001 (10°C), 0.014 ± 0.001 (15°C), 0.019 ± 0.001 (25°C), 0.024 ± 0.001 (30°C), 0.027 ± 0.001 (35°C) and 0.040 + 0.003 (50°C). This indicates a remarkable dependence on temperature. The effect of the Mg2+/Ca2+ molar ratio in a parent solution on λMg for calcite is small, where the molar ratio lies in the range 0.04-2. However, the λMg value for aragonite tends to decrease with increasing Mg2+/Ca2+ ratio in the parent solution. The largest Mg content of calcite in the Ca(HCO3)2-Mg2+ → calcite system is around 2 mol% in the temperature range 10–50°C. Neither homogeneous nor heterogeneous distribution laws hold for aragonite precipitation, and the temperature effect on the coprecipitation of Mg2+ ions with aragonite is very small. 相似文献
9.
Shallow marine carbonate sediments near the Dry Tortugas undergo extensive biogeochemical diagenesis upon deposition, resulting
in postdepositional fabric comprised of micritic aggregates of clay-sized particles, a matrix of peloidal mud, and intraparticular
cementation. Freshly deposited primary skeletons, mostly Halimeda fragments, yield micritic aggregates of clay-sized particles, which then form peloidal mud fabric upon compaction. The cryptocrystalline
particles produced by micritization are later replaced by high magnesian calcite. Cementation is observed in the intra-particular
microenvironment. However, no inter-particular, grain-binding cement was detected throughout the gravity core samples investigated. 相似文献
10.
碳酸盐生物壳体的周期性生长纹层是记录气候环境变化的天然材料。随着原位微区测试技术的快速发展,高分辨率的同位素和化学元素组成的快速分析显著推动了古气候环境变化及生物地球化学研究。应用激光剥蚀等离子体质谱仪(LAICP-MS)对南黄海现代牡蛎Crassostrea gigas壳体韧带部的元素组成进行原位微区测试,利用内标元素43Ca进行元素比值的校正,探讨了牡蛎壳中化学元素特征及其环境意义。研究的长牡蛎壳体中Mg/Ca、Sr/Ca、Na/Ca比值具有显著的季节性周期变化。环境水体物理化学性质的变化对壳体生长速率影响较大,壳中白垩质方解石和叶片方解石生长层分别对应较高和较低的环境温度,白垩方解石层具有较高的Mg/Ca、Sr/Ca和较低的Na/Ca比值。Mg/Ca比值可指示牡蛎壳体生长环境水体温度,利用前人Mg/Ca比值公式计算可以恢复与器测资料相符的近岸海水温度结果。本研究对应用LA-ICP-MS分析技术开展高分辨率的生物壳体元素组成和环境示踪研究具有借鉴意义。 相似文献
11.
The adsorption of Pb2+ and of Cd2+ ions from calcareous Krka river water of various salinities (3, 14, 20 and 38 psu) on calcite (CaCO3, Merck p.a.) was investigated. Simultaneous adsorption of Pb2+ and Cd2+ ions was studied as well. The results suggest that the two ions are adsorbed at different calcite surface sites; Pb2+ remained firmly bound to calcite at all salinities, whereas Cd2+ was firmly bound at low salinities and released at high salinities. Dissolved natural organic ligands at the freshwater-seawater interface (FSI; at 14 psu) promoted and below the FSI (at 20 psu) decreased the adsorption of Cd2+. The experiments were performed at metal concentrations of 8 × 10−8 mol l−1 and at natural pH values around pH 8. Adsorbed amounts of trace metal ions were determined in filtered samples by differential pulse anodic stripping voltammetry (DPASV) with a three-electrode system, after 24 h of equilibration with calcite. Several adsorption models were tested, such as Freundlich's, Langmuir's and Schindler-Stumm's surface coordination model. Adsorption isotherms belong to S-1 class of empirical adsorption isotherms. None gave reasonable values of adsorption constants. The fractional partitioning of adsorbent to the solid phase when normalized to the quantity of adsorbent present (Kd) declined as solid concentration increased. It was found that the surface charge is not responsible for the observed effect. Instead, aggregate size increased, which effected a loss in surface area. This is a reasonable explanation for the observed S-shaped adsorption isotherms curves. 相似文献
12.
国内外贝类学界都认为贝壳角质层仅由贝壳素构成.棱柱层由方解石构成.珍珠层通常为霰石构成.日本的小林新二郎提出棱柱珍珠是方解石结构,国内外许多论文对此都没有提出异议.本研究采用X-射线对贝壳和棱柱珍珠衍射结果证明:(1)贝壳珍珠层全是是霰石结构,只有牡蛎(Ostrea rivularis)壳例外,符合以上理论;(2)棱柱层几乎全是霰石结构,只有牡蛎壳和紫色裂江珧(Pinna atropurpurea)壳的棱柱层是方解石结构,基本否定了以上理论;(3)角质层由有机物—贝壳素和方解石或霰石组成的,有些还含二氧化硅等杂质,这不完全相符上面理论;(4)棱柱珍珠完全是霰石结构,证明小林新二郎的结论是错误的. 相似文献
13.
The responses of atmospheric pCO2 and sediment calcite content to changes in the export rain ratio of calcium carbonate to organic carbon are examined using
a diffusion-advection ocean biogeochemical model coupled to a one-dimensional sediment geochemistry model. Our model shows
that a 25% reduction in rain ratio decreases atmospheric pCO2 by 59 ppm. This is caused by alkalinity redistribution by a weakened carbonate pump and an alkalinity increase in the whole
ocean via carbonate compensation with decreasing calcite burial. The steady state responses of sedimentary calcite content
and calcite preservation efficiency are rather insensitive to the deepening of the saturation horizon of 1.9 km. This insensitivity
is a result of the reduced deposition flux that decreases calcite burial, counteracting the saturation horizon deepening that
increases calcite burial. However, in the first 10,000 years the effect of reduced calcite deposition on the burial change
is more prominent; while after 10,000 years, the effect of saturation horizon deepening is more dominant. The lowering of
sediment calcite content for the first 10,000 years is effectively decoupled from the 1.9 km downward shift of the saturation
horizon. Our results are in part a consequence of the more dominant role that respiration CO2 plays in sediment calcite dissolution over bottom water chemistry in our control run and support the decoupling of calcite
lysocline depth and saturation horizon shifts, as suggested originally by Archer and Maier-Reimer (1994) and Archer et al. (2000). 相似文献
14.
2015年10月中旬,在浙江省舟山市近海的渔业资源调查中采集到天竺鲷标本,经鉴定发现其中黑边银口天竺鲷为浙江新纪录种。本文对采集的6尾黑边银口天竺鲷标本拍摄照片并开展形态特征和DNA条形码研究,对该种的拉丁学名进行校正。黑边银口天竺鲷的有效学名为Jaydia truncata(Bleeker,1854)。具有以下主要形态特征:背鳍鳍条数VII+I,9,胸鳍鳍条数16—17;背前鳞数4;第一鳃弓总鳃耙数3—4+11—13,发达鳃耙数1+9—10,角鳃弓上的鳃耙数9;前鳃盖骨边缘锯齿状;第一背鳍上端黑色,第二背鳍及尾鳍边缘黑色,第二背鳍与臀鳍中部各具一黑色纵纹。本研究分析了浙江海域5种天竺鲷科鱼类的形态差异,并编制了检索表。测定了6尾标本的DNA条形码,结合Gen Bank中所有学名为Jaydia truncata及其同种异名的同源序列分析,发现所有个体明显分为两个分支,且两者遗传距离达到0.149,表明两分支可能为不同的有效种,Gen Bank中只有AB890050和JQ681488与本研究序列结果相近。 相似文献
15.
Dissolved and particulate manganese in seawater samples derived from the English Channel has been analyzed using graphite furnace atomic absorption (GFAAS), and inductively coupled plasma atomic emission (ICP—AES) spectroscopies. Because of the high contents of carbonate minerals found in the suspended matter samples, the English Channel constitutes an ideal field area for the study of the Mn2+/Ca2+/CaCO3 system. Owing to the chemical speciation of particulate manganese and the combined use of the X-ray diffraction and electron spin resonance spectroscopy we have shown the importance of the carbonate phase in the stabilization of manganese (II). This has been confirmed by p-pH measurements in the field. All these studies have also indicated that: (1) manganese is associated with calcite in the form of a solid solution, MnxCa1−xCO3; and (2) significant increases in the concentrations of particulate manganese, especially in offshore waters, occur in summer. This seasonal phenomenon has been attributed to the proliferation of coccolithophorids, which are known to be covered with calcified skeletons at high specific surface areas. To appraise the implication of the coccolithophorid-blooms phenomenon on the Mn2+/Ca2+/CaCO3 system, we have used the manganese distribution coefficient, Di, between the liquid phase and CaCO3 particles. Overall we have shown that: (1) Di in summer (i.e. when coccoliths considered as very fine-grained calcite are abundant) is much higher than that obtained in winter; and (2) in the vicinity of the French coast, Di does not vary significantly even in summer. This is because of the high content of chalk-derived particles found in the near-shore waters. 相似文献
16.
Acropora coral colonies as microhabitats for sponges in Tayrona National Natural Park,Colombian Caribbean 
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下载免费PDF全文 Sponges are sessile organisms capable of colonizing diverse substrata. In the Caribbean, coral reefs have suffered a drastic decline, and branching corals of the genus Acropora have been widely decimated. On dead coral skeletons and around surviving tissue the settling of sessile organisms can be observed, sponges being common. In order to investigate whether or not sponges have a preference for a particular species of coral, or for specific microhabitats of the colonies, we evaluated species composition, cover, richness and diversity of sponges colonizing the dead parts of still live colonies of the branching corals Acropora palmata and Acropora cervicornis in five locations of the Tayrona National Natural Park in the Colombian Caribbean. Ten colonies of Ac. palmata were quantified in each of the five locations, and eight Ac. cervicornis colonies in each of two locations. Quantification was carried out using video taken within 0.625‐m2 photoquadrats. Seventeen sponge species were found, 13 of them associated with Ac. palmata and seven with Ac. cervicornis. Desmapsamma anchorata, Clathria venosa and Scopalina rutzleri were found to be common to all Ac. palmata locations, while De. anchorata occurred in the two Ac. cervicornis locations. On Ac. palmata, encrusting sponges dominated, while on Ac. cervicornis branched and lobed sponges predominated. Significant differences in sponge cover were not found among locations but were observed in the sponge species present. On Ac. palmata the species with highest cover were D. anchorata and Cla. venosa, while on Ac. cervicornis it was De. anchorata. The richness and diversity of sponges were low for both coral species, and their varying distribution can be attributed to the differences in available substrate for attachment, given coral colony morphology; for Ac. palmata, sponges predominated on the underside of the branches, semi‐cryptic areas and colony bases, whereas for Ac. cervicornis, they were located over the entire area of the cylindrical branches. Surviving colonies of Ac. palmata and Ac. cervicornis that are still erect offer additional microhabitats for reef sponges, some of which can be found directly interacting with live coral tissue, further threatening their recovery. 相似文献
17.
以肌动球蛋白含量、Ca2+-ATPase酶活性、总巯基活性(T-SH)和活性巯基(A-SH)含量为考察指标,研究了用不同pH的酸性电解水、以不同的时间对凡纳滨对虾进行减菌化处理后,对虾肌肉的生理特性及肌肉品质的变化。结果表明:电解水的酸性越强、处理时间越长,对虾的肌动球蛋白、T-SH和A-SH的含量越低,Ca2+-ATPase的酶活越小。当对虾在pH分别为2.62、3.18、4.06的酸性电解水中处理60min后,肌动球蛋白含量分别损失了98.7%、90.0%、73.7%,Ca2+-ATPase的失活率分别为93.4%、87.8%、84.3%,T-SH含量分别减少了57.8%、42.3%、40.3%,A-SH含量分别减少了77.8%、65.9%、30.7%。说明酸性电解水的减菌化条件对虾肉的生化指标影响显著。 相似文献
18.
The variation in mycosporine‐like amino acid (MAA) concentration in the soft coral Heteroxenia fuscescens in relation to changes in ultraviolet radiation (UVR) regimes was investigated at the Gulf of Eilat, northern Red Sea. Solar radiation (300–700 nm) was measured for different depths and seasons. The UVR irradiance was measured to a depth of 25 m on the reef. The mean attenuation coefficient for UV‐B measured in winter was twofold that of the summer value. Separation of H. fuscescens extracts by reverse‐phase isocratic high‐performance liquid chromatography revealed a single MAA compound, palythine (λmax = 320 nm). Possible seasonal changes in MAAs in colonies of H. fuscescens along a depth gradient were examined on different dates. Palythine concentrations in the colonies were significantly higher in summer than in the other seasons particularly in shallow water. Possible changes in MAA content in colonies of H. fuscescens as a result of UVR protection, were determined by experiments conducted for periods of 1 week, 1 month and 3 months, at a depth of 5 m. In these experiments colonies were removed from the natural substrate and placed underwater, protected from UVR by a PVC filter. Significant differences between UV‐exposed and protected colonies of H. fuscescens were found only in the 3‐month experiment conducted during the summer. These findings demonstrate that UVR is an important environmental factor regulating MAA biosynthesis in the soft coral H. fuscescens. 相似文献
19.
The coprecipitation of uranium with calcium carbonate 总被引：1，自引：0，他引：1
This report is one of the studies on the factors controlling the trace element contents of marine calcareous skeletons. The values of the distribution coefficients of UO2
2+ between solutions and carbonate precipitates were measured in the laboratory at 20±1C. From the determination of the uranium contents of marine calcareous skeletons and sea water, the values of uranium between marine calcareous skeletons and sea water are expected as 1.2 to 0.3 for aragonite and 0.2 to 0,0n for calcite. The experimentally measured value of the distribution coefficient for aragonite is thermodynamically discussed. And it was known that the value of the distribution coefficient of UO2
2+ is controlled greatly by the activity coefficient of uranium dissolved in a parent medium and the crystal form of CaCO3. The activity coefficient of uranium in solution mainly owes to the formation of complexes between UO2
2+ and CO3
2–in the solution. 相似文献
20.
Eight new species of copepods associated with shallow-water ascidians are described from the eastern coast of Korea. They
are Ascidicola secundus n. sp. from a Pyura sp., Enteropsis nudus n. sp. from Pyura sacciformis (Drasche), Mycophilus capillatus n. sp. from a compound ascidian, Bonnierilla yangpoensis n. sp. from Phallusia cf. nigra Savigny, Janstockia truncata n. sp. from Chelyosoma siboja Oka, Pholeterides pilosa n. sp. from a compound ascidian, Pachypygus spinosus n. sp. from a solitary ascidian, and Paranotodelphys unguifer n. sp. from Ascidia samea Oka. 相似文献