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1.
Knowledge of coral recruitment patterns helps us understand how reefs react following major disturbances and provides us with an early warning system for predicting future reef health problems. We have reconstructed and interpreted historical and modern-day recruitment patterns, using a combination of growth modelling and in situ recruitment experiments, in order to understand how hurricanes, storms and bleaching events have influenced coral recruitment on the Caribbean coastline of Tobago. Whilst Tobago does not lie within the main hurricane belt results indicate that regional hurricane events negatively impact coral recruitment patterns in the Southern Caribbean. In years following hurricanes, tropical storms and bleaching events, coral recruitment was reduced when compared to normal years (p = 0.016). Following Hurricane Ivan in 2004 and the 2005–2006 bleaching event, coral recruitment was markedly limited with only 2% (n = 6) of colonies estimated to have recruited during 2006 and 2007. Our experimental results indicate that despite multiple large-scale disturbances corals are still recruiting on Tobago’s marginal reef systems, albeit in low numbers. 相似文献
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珊瑚礁地质稳定性研究现状 总被引：1，自引：1，他引：0
为探究珊瑚礁稳定性的研究现状,对影响礁体稳定性的诸多因素如礁体结构、地形地貌、波浪、潮汐、潮流、风诸如热带气旋和风暴、海流等进行总结,结果表明以上诸多因素可在不同程度上决定或影响礁体稳定性。同时指出现阶段礁体稳定性研究所需注意的问题,其一是涉及珊瑚礁地质稳定性的礁体结构、地貌形态的研究尚少,需合理利用多波束测深仪、高分辨率多道地震探测系统、钻探及AUV、三维实时声学成像声呐技术获取礁体地形、地层及剖面形态,并借助GIS技术对滑坡等失稳地带进行圈定,其二是潟湖区、礁体边坡等区域的稳定性研究缺乏,需引入极限平衡法评估礁体边坡、泻湖等区域的稳定性,且需考虑波浪、潮汐引入的孔隙水压力、渗流力的影响。通过综述礁体稳定性研究现状及未来礁体稳定性研究的方向的展望,以期为珊瑚礁体上的工程建设及未来的珊瑚礁地质稳定性研究提供些许启示。 相似文献
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Representative profiles of inorganic nitrogenous species dissolved in interstitial waters of coral reef sands are presented. Ammonium is the dominant nitrogenous species in these pore waters with concentrations of up to 40 μm. Nitrate is present but in lower concentrations. Nitrite is found only occasionally in trace amounts. Computations of diffusive fluxes and inferences concerning microbial activity are derived from the profile structures. Computed flux rates of nitrogenous species from the sediment to the water column range between 0.75 and 1.37 μM m−1 h−1. These inputs may represent a significant source of recycled nitrogen to the primary producers of the coral reef ecosystem. 相似文献
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Ihavandippolu, the northernmost atoll of the Maldives, experienced severe coral bleaching and mortality in 1998 followed by several bleaching episodes in the last decade. Coral cover in the 11 study sites surveyed in July–December of 2011 in the 3–5 m depth range varied from 1.7 to 51%. Reefs of the islands located in the center of Ihavandippolu lagoon have exhibited a very low coral recovery since 1998 and remain mostly degraded 12 years after the impact. At the same time, some reefs, especially in the inner part of the eastern ring of the atoll, demonstrate a high coral cover (>40%) with a dominance of branching Acropora that is known to be one of the coral genera that is most susceptible to thermal stress. The last severe bleaching event in 2010 resulted in high coral mortality in some sites of the atoll. Differences in coral mortality rates and proportion between “susceptible” and “resistant” taxa in study sites are apparently related to long-term adaptation and local hydrological features that can mitigate thermal impacts. Abundant herbivorous fish observed in the atoll prevent coral overgrowth by macroalgae even on degraded reefs. Despite the frequent influence of temperature anomalies and having less geomorphologic refuges for coral survivals than other larger Maldivian atolls, a major part of observed coral communities in Ihavandippolu Atoll exhibits high resilience and potential for further acclimatization to a changing environment. 相似文献
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Scleractinian coral population size structures and growth rates indicate coral resilience on the fringing reefs of North Jamaica 总被引：1，自引：1，他引：0
Coral reefs throughout the world are under severe challenges from many environmental factors. This paper quantifies the size structure of populations and the growth rates of corals from 2000 to 2008 to test whether the Discovery Bay coral colonies showed resilience in the face of multiple acute stressors of hurricanes and bleaching. There was a reduction in numbers of colonies in the smallest size class for all the species at all the sites in 2006, after the mass bleaching of 2005, with subsequent increases for all species at all sites in 2007 and 2008. Radial growth rates (mm yr−1) of non-branching corals and linear extension rates (mm yr−1) of branching corals calculated on an annual basis from 2000–2008 showed few significant differences either spatially or temporally. At Dairy Bull reef, live coral cover increased from 13 ± 5% in 2006 to 20 ± 9% in 2007 and 31 ± 7% in 2008, while live Acropora species increased from 2 ± 2% in 2006 to 10 ± 4% in 2007 and 22 ± 7% in 2008. These studies indicate good levels of coral resilience on the fringing reefs around Discovery Bay in Jamaica. 相似文献
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鹿角珊瑚人工养殖的初步研究 总被引：1，自引：0，他引：1
为了探讨珊瑚人工养殖的基本条件和方法,分别在陆基水泥池中和海底珊瑚苗床上对3种鹿角珊瑚:粗野鹿角珊瑚(Acropora humilis)、霜鹿角珊瑚(Acropora pruinosa)和松枝鹿角珊瑚(Acropora brueggemanni)的人工养殖进行了实验。结果表明,这3种珊瑚可以在深圳市鹅公湾近岸海域的海底珊瑚苗床上常年生长;在水泥池中当水温低于14℃或高于28℃时珊瑚陆续死亡;这3种珊瑚的生长速度在适温范围内随着水温的升高而加快,最大月生长值是6.05 mm;光照对这3种珊瑚的生长有影响,直接的阳光照射会引起水泥池中珊瑚的死亡。 相似文献
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High inorganic phosphate concentration in coral mucus and its utilization by heterotrophic bacteria in a Malaysian coral reef 
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下载免费PDF全文 Ryota Nakajima Yasuaki Tanaka Teruaki Yoshida Tamami Fujisawa Asami Nakayama Yumi Fuchinoue Bin Haji Ross Othman Tatsuki Toda 《Marine Ecology》2015,36(3):835-841
Inorganic nutrient contents of mucus released by Acropora corals and its utilization by heterotrophic bacteria at several different hour intervals in the coral mucus were investigated at a coral reef in Malaysia. The dissolved inorganic phosphate (DIP) concentration was 135‐fold higher than in the ambient seawater, probably due to inorganic P release from the coral gut cavity. We experimentally confirmed that heterotrophic bacteria rapidly (within 8 h) consumed ca. 80% of the initial concentration of DIP derived from coral mucus. High DIP concentration in coral mucus may enhance heterotrophic bacterial production and associated carbon flow in the microbial loop of reef ecosystems. 相似文献
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Assessment of the effectiveness of natural coral fragmentation as a dispersal mechanism for coral reef‐boring sponges 下载免费PDF全文
下载免费PDF全文 Eastern Pacific reefs are mostly made up of interlocking coral branches of Pocillopora, which are easily broken by physical forces associated with heavy swells and winds. In this study we investigated the potential of these coral fragments to enable propagation of boring sponges. For this, we quantified the frequency of occurrence and diversity of boring sponges in fragments of corals recently trapped among the branches of live colonies, and later tested the hypothesis that these sponges colonize new branches of corals. Nearly 80% of the coral colonies investigated had coral fragments among their branches, and 69% of these coral fragments contained boring sponges (11 species), some of these sponges in reproduction (23% of them carried oocytes). To test whether sponges inhabiting coral fragments could colonize new branching corals we transplanted them to healthy branches, and to branches whose living tissue was mechanically eliminated to simulate damage produced by grazing and death after bleaching and other causes of coral tissue mortality. All the transplanted coral fragments cemented to each new colony by means of calcification, and of the three sponge species tested (Cliona vermifera, Cliona tropicalis and Thoosa mismalolli) only C. vermifera was able to colonize both new living branches (26.9%) and cleaned branches (65.5%). The apparent capability of C. vermifera to colonize by direct contact may be another key ability of this species to maintain high frequency of occurrence in Pacific coral reefs. However, although C. tropicalis and T. mismalolli were not able to colonize new coral substrata by direct contact, coral fragments have the potential to contribute to local persistence of these sponges and to their dispersal, both by asexual (fragments) and sexual means (transport of sexual products). The present findings may partly explain the current increase of excavating sponges on deteriorating reefs with a large availability of dead branching corals. 相似文献
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Addressing the coral reef crisis in developing countries 总被引：2，自引：0，他引：2
Johann D. Bell Blake D. Ratner Ilona Stobutzki Jamie Oliver 《Ocean & Coastal Management》2006,49(12):976-985
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Tatsuki Toda Tomoko Okashita Takeshi Maekawa Bin Abdul Adzis Kee Alfian Mohd Kushairi Mohd Rajuddin Ryota Nakajima Wenxi Chen Kunio T. Takahashi Bin Haji Ross Othman Makoto Terazaki 《Journal of Oceanography》2007,63(1):113-123
Coral community structures at eleven fringing reef sites were investigated along the coast of Peninsular Malaysia. Estimated
coverage of coral communities is examined by applying quantitative digital image analysis to the line transect method. Four
coral community types were characterized by dominant genera and lifeforms: Acropora branching community, Montipora-Acropora community, Porites massive community, and Heliopora community. Live coral coverage in all study sites ranged from 17.9% to 68.6%. Most reefs were in “fair” condition while some
reefs were shown to be in “poor” condition. Coral community structures among the study sites were divided into the west coast
of Peninsular Malaysia with a dominant Porites massive lifeform, and the east coast with a variety of lifeform categories of Montipora and Acropora. Physical effects such as the monsoon wind regime and sedimentation are likely to influence the formation of dominant coral
communities around Peninsular Malaysia. 相似文献
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珊瑚礁坪波浪的衰减特性分析 总被引：1，自引：0，他引：1
珊瑚礁海底与一般的礁石或泥沙海底结构相差很大，波浪衰减特性也相差较大。根据实测海浪资料，讨论波浪在礁坪上传播的衰减特性和波浪能量的转移。分析结果表明，在相对水深为0．0613—0．0867之间，波浪传播单位距离(100m)的波高衰减系数为22．09％—46．56％，平均值为31．35％；波能衰减系数为33．74％—53．23％，平均值为43．61％。波浪在礁坪上传播过程中，高频损失的能量多于低频，谱能量向低频转移。应用统计方法得到波高、波能衰减系数与相对水深D/L关系的拟合方程。 相似文献
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《Ocean & Coastal Management》2000,43(8-9):657-688
Coral reefs are among the most productive and diverse ecosystems on earth and provide a multitude of valuable ecosystem services. Moreover, the resources derived from coral reefs are essential to the food security of millions of people living within tropical coastal communities. Unfortunately, burgeoning human populations in coastal regions are placing an unsustainable burden on these resources such that degradation of coral reefs is common. In addition, during 1998, El Niño driven increases in sea temperature caused a mass bleaching event that further degraded many of the world's coral reefs. This article provides a brief review of the status of the world's coral reefs and highlights their value to society. Also, the anthropogenic and natural disturbances that threaten the future of coral reefs are discussed and finally, this article offers some potential remedies that promote sustainable use of coral reef resources thus ensuring their future survival. 相似文献
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全珊瑚骨料海水混凝土力学性能试验研究 总被引：3，自引：1，他引：2
为了探讨全珊瑚骨料海水混凝土的基本力学性能,并比较其与普通混凝土和轻集料混凝土的差异,通过实验系统测定了珊瑚混凝土的基本力学性能,建立了其轴心抗压强度(f_(c,m))、劈裂抗拉强度(f_(sp,m))、抗折强度(f_(t,m))与立方体抗压强度(f_(cu,m))之间的线性关系与计算公式。结果表明:在强度等级C20~C50的范围内,珊瑚混凝土的f_(c,m)和f_(sp,m)分别比普通混凝土的f_(c,m)和f_(sp,m)高出10%~48%和9%~33%,随着强度等级的提高,两种混凝土之间的差距在减小。珊瑚混凝土的f_(t,m)与普通混凝土的ft,m之间的差异规律与强度等级有关,较低强度等级的C30珊瑚混凝土ft,m比普通混凝土的f_(t,m)要高4%,而较高强度等级的C55珊瑚混凝土f_(t,m)比普通混凝土的f_(t,m)低13%。较高强度等级的C50珊瑚混凝土f_(c,m)、f_(sp,m)和f_(t,m)分别比页岩陶粒轻集料混凝土的f_(c,m)、f_(sp,m)和f_(t,m)低11%、0.9%和4%。 相似文献
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Given the threat of climate change towards scleractinian corals, there is an urgent need to understand their physiological mechanisms of acclimation to increasing temperatures. To gain insight into this process, two mesocosm-based experiments were conducted in Southern Taiwan with the model reef-building coral Pocillopora damicornis. In the first study, temperature was gradually elevated to 32 °C, though reduced to ambient levels at night, in order to simulate a temperature profile that can characterize intertidal reefs of Southern Taiwan. All corals acclimated to such conditions over the course of the month-long experiment, as evidenced by a variety of physiological and sub-cellular responses. In the second experiment, corals were exposed continually to 31.5 °C for two weeks, and, in contrast to results from the first study, the majority of the corals died, revealing that prolonged exposure to this temperature is lethal for this dominant reef builder of many regions of the Pacific Ocean. 相似文献
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In this study, we used digital borehole image camera to obtain images of porosity distribution in coral reefs in South China Sea, and developed an effective evaluation system for such distributions. First, the original images are preprocessed, allowing the pore regions to be automatically detected. The depth and sectional functions are established to measure five parameters: pore count, pore radius, radius concentration rate, total pore area ratio, and fractal dimension count. These are used to calculate the characteristic values of porosity distributions, and their fuzzy relationships are used to build the evaluation model, determine the Hamming distances between distributions, and establish the relationships between the characteristics and coral rock classifications. Test results from applying the method on a deep borehole image segment show the results to be consistent with other methods, and the following conclusions can be reached: (1) the porosity evaluation model is a viable way to analyze porosity distribution characteristics; (2) the resulting classification method is viable; and (3) porosity distribution analysis on coral reefs has important implications. 相似文献
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石珊瑚骨骼对重建古海洋古气候环境,评估珊瑚礁对未来气候变化、海洋酸化的响应和反馈,辨识现存造礁石珊瑚种属及其演化途径有着十分重要的作用和意义。为了更好地认知造礁石珊瑚骨骼特征,在三亚海域采集了常见的造礁石珊瑚——鹿角杯形珊瑚Pocillopora damicornis,通过扫描电镜(结合EDS能谱仪)、红外分光显微镜分析其碳酸钙骨骼结构和成分的特征,结果表明鹿角杯形珊瑚骨骼主要成分为文石,少数骨骼样品的空腔中发育有极少量方解石矿物。虽然鹿角杯形珊瑚骨骼宏观架构和中观架构在群体间和单体间存在诸多差异,但不同形态的骨骼样品具有基本相同的发育模式和基础结构单元。同时,发现鹿角杯形珊瑚骨骼内部空腔存在有次生文石沉积发育现象,同时常伴生着水镁石矿物的发育,而且这与骨骼中的钻孔穴居动物有很大关联。 相似文献
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沉积物对珊瑚礁及礁区生物的影响 总被引：2，自引：0，他引：2
海水中日益增多的悬浮物和泥沙沉降是导致珊瑚礁严重衰退的原因之一。沉积物覆盖在珊瑚礁生物表面,影响其呼吸作用,而海水浊度的增加会减少光合作用的可利用光。过多的沉积物改变了礁区的物理以及生物过程,从而对珊瑚礁生态系的结构和功能产生不利影响。为了有效评估珊瑚礁的变化趋势,如优势种丰度以及空间分布的变化等,应用标准的监测方法进行长期监测对于掌握这一复杂生态系统的变化是非常关键的。综述了沉积物对珊瑚生长率、生长形态、代谢和繁殖与补充以及礁区生物的影响,并指出未来的研究方向,以期为珊瑚礁的保护提供参考。 相似文献