生态礁体布置形式对水流特征的影响

为满足生态需求,生态礁群内需要营造具有特定要求的水动力环境,且结构内部不能淤堵。在淤积型潮间带,需要通过合理的礁体布置,并在波浪作用下实现。针对生态礁体格栅面迎浪对齐摆放、中空面迎浪对齐摆放和交错摆放3种布置方式,通过断面物理模型试验研究生态礁体场内水流形态、流速分布特征。结果表明:1)在波浪作用下,礁体结构内外侧流场均呈三维特征,礁体群内各点流速衰减总体上呈均匀递减的形态。2)在平常波浪条件下,中空迎浪对齐摆放方式流速衰减至0.5~1.0 m/s,较好地符合了生态礁体场内流速的要求。

湖南新邵巨口铺中泥盆世棋梓桥期生物礁群落生态

湖南新邵巨口铺中泥盆世棋梓桥期台缘礁可分为５个群落（自下而上）：Ｓｔｒｏｍａｔｏｐｏｒａ－Ｃｌａｔｈｒｏｃｏｉｌｏｎａ群落；（２）Ａｒｇｕｔａｓｔｒｅａ－Ｓｔｒｏｍａｔｏｐｏｒａ群落；（３）Ｃｒｉｎｏｉｄｓ－Ｃｌａｔｈｒｏｃｏｉｌｏｎａ群落；（４）Ｃｌａｔｈｒｏｃｏｉｌｏｎａ－Ｐｌａｎｏｃｏｅｎｉｔｅｓ群落；（５）Ａｍｐｈｉｐｏｒａ－Ａｃｔｉｎｏｓｔｒｏｍａ群落。对每个群落的居群数（Ｓ），相对丰度（Ｐ），分异度（Ｈ），优势度（Ｃ）和均衡度（Ｅ）以及生物生活方式、进食类型等进行了计算和描述。根据各居群在礁体形成过程中所起的作用，划分为５个群团：建造者、粘结者、保护者、居住者和破坏者。礁体发育经历４个阶段，每个阶段都有一定的造礁方式──格架式、捆结式、盖覆式和障积式。文中共鉴定８０种、５４属，分属于１１个大类。

生态混凝土鱼礁的应用及发展趋势

近年来,生态混凝土鱼礁广泛应用于海洋牧场中,相对于传统人工鱼礁材料,其多孔结构为海洋动植物提供了更加广阔的生存生长空间,有利于改善海洋生态环境,保护生物多样性。对生态混凝土鱼礁展开介绍,阐述其意义及国内外应用现状,并论述其发展趋势。

地球环境变化对白垩纪礁生态系统的控制

我们发展全球环境控制礁的生态系统这一假说，目的是为了解释白垩纪底栖群落中生物发生的急剧变化。在早白垩世一个３千万年的时间段中，礁生态系统中的主要生物由珊瑚类、藻类和厚壳蛤类转变成为带有小型珊瑚种的厚壳蛤类。这种转变包括营粘性生活方式生物的减少，在早白垩世粘性生物主要是指层孔虫类和藻类的蓝藻细菌共生组合。在中白垩世，充当保护者的首先是辐射蛤类，接着是马尾蛤类，它们的作用得到了加强，并且种类变得多样，

近岸海上风电场与海洋牧场构建融合方案初探——以金山海上风电场二期项目为例

随着“碳达峰”“碳中和”时代的来临,风电作为新型电力系统构建的主体,是我国一直以来重点发展的一项可再生能源,受到了广泛的应用。文章从政策符合性、水文条件、建造位置与鱼类重要场所等多方面构建评价体系,以金山海上风电场二期项目为例,对海洋牧场与近岸海上风电场融合构建进行初探。结果表明,由于流速、水深、水质环境等原因,金山海上风电场二期项目场址不具备建设海洋牧场和人工鱼礁建设的条件。建议通过投放生态礁、增殖放流等方式,逐渐形成良性循环的海洋生态环境。基于以上工作,初步探索近岸海上风电场与海洋牧场构建融合方案,开展河口海上风电项目的海洋生境构建。

渤海湾西北岸的几道牡蛎礁

渤海湾西北岸划分出了第Ⅰ道—第Ⅵ道牡蛎礁的平面分布(图1);对牡蛎礁壳体的几何形态特征进行了描述(图2),并将牡蛎礁壳体进行了剖面切割(图3);对牡蛎礁壳体进行了X光衍射与激光拉曼(活—古)矿物晶型的对比分析(表1,图4);对俵口村BKP20-2剖面(-2.84m)牡蛎礁一个体右壳:在双目镜下对其内部结构与矿物组分进行了分析(图5);通过机械挖掘剖面及钻探获得:牡蛎礁体的空间堆积厚度与赋存的海拔高度及其各剖面垂直方向上的14C年代数据;并获得牡蛎礁体堆积的内部结构特征(图6);以及牡蛎礁体水平夹层与CaCO3含量变化(图7),其中水平夹层CaCO3含量往往偏高,初步分析可能与气候偏冷有关。对牡蛎礁壳体内充填物及壳外沉积物进行了粒度分析(表3),粒度组分及概率累积曲线等(图9)为分析牡蛎礁的生态环境提供了佐证:即牡蛎礁基本以潮下带生活环境为主。以俵口BKP20剖面为例分析了牡蛎礁体堆积物从埋深-2.14～-6.90m的生物组合特征(表4)。以上资料为获得牡蛎礁堆积体的生长-发育-消亡等演化模式提供了依据(图10)。

Sewage pollution in Negril, Jamaica: effects on nutrition and ecology of coral reef macroalgae

Coral reefs in the Negril Marine Park （NMP）, Jamaica, have been increasingly impacted by nutrient pollution and macroalgal blooms following decades of intensive development as a major tourist destination. A baseline survey of DIN and SRP concentrations, C：N：P and stable nitrogen isotope ratios （δ^15N） of abundant reef macroalgae on shallow and deep reefs of the NMP in 1998 showed strong P-limitation and evidence of increasing sewage pollution. In 1999, a sewage collection and treatment project began diverting wastewater from the resort and urban areas to a pond system that discharged partially-treated effluent into the South Negril River （SNR）. These sewage discharges significantly increased concentrations of NH2 and SRP （N：P -13） in the SNR, which flows into Long Bay and around Negril＇s ＂West End＂. Concentrations of SRP, the primary limiting nutrient, were higher on shallow reefs of the West End in 2001 compared to 1998. Stable nitrogen isotope ratios （δ^15N） of abundant reef macroalgae on both shallow and deep reefs of the West End in 2002 were significantly higher than baseline values in 1998, indicating an escalating impact of sewage nitrogen pollution over this timeframe. The increased nutrient concentrations and δ^15N enrichment of reef macroalgae correlated with blooms of the chlorophyte Chaetornorpha linum in shallow waters of Long Bay and Codium isthrnocladum and Caulerpa cupressoides on deep reefs of the West End. Sewage treatment systems adjacent to coral reefs must include nutrient removal to ensure that DIN and SRP concentrations, after dilution, are below the low thresholds noted for these oligotrophic ecosystems.

Regional hard coral distribution within geomorphic and reef flat ecological zones determined by satellite imagery of the Xisha Islands,South China Sea

Coral reefs in the Xisha Islands （also known as the Paracel Islands in English）, South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef fiat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health （live versus dead cover） for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was 〈10%. The total Xisha reef system was estimated to cover 1 060 km2, and the emergent reefs covered -787 km2. Hard corals of emergent reefs were considered to cover 97 km2. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems.

Seasonal Gametogenesis of Host Sea Anemone(Entacmaea quadricolor) Inhabiting Hong Kong Waters

Studying gonadal development of annual cycle can reveal the process of gametogenesis and reproductive period, and evaluate fertility and source utilization of a species. Host sea anemones are conspicuous members of tropical and subtropical reef ecosystems, but little is known about its biology including reproductive seasonality. Here we reported a one-year study on the gametogenesis and reproduction of host sea anemone(Entacmaea quadricolor) inhabiting Hong Kong waters. E. quadricolor tissues were sampled in 12 occasions from 5 m and 15 m depths of water, respectively. Histological sectioning of the tissues showed that E. quadricolor was dioecious, and populational ratio of female to male was 1:1.6. The gonadal development was asynchronous within an annual cycle, which included proliferating, growing, maturing, spawning, and resting stages. The spawning occurred between August and October when surface seawater temperature reached the annual maximum(28℃), suggesting that temperature is an important factor modulating the gonadal development and mature of E. quadricolor.

Coral Reef Recovery Status in South Andaman Islands after the Bleaching Event 2010

The Andaman and Nicobar Islands are one of the Union Territories of India, located in the eastern part of the Bay of Bengal. In 2010 summer, the increment in sea surface water temperature （up to 34℃） resulted in the bleaching of about 74% to 77% of corals in the South Andaman. During this event, coral species such as Acropora cerealis, A. humilis, Montipora sp., Favia paIlida, Diploastrea sp., Goniopora sp. Fungia concinna, Gardineroseries sp., Porites sp., Favites abdita and Lobophyllia robusta were severely affected. This study is to assess the recovery status of the reef ecosystem by estimating the percentage of Live Coral cover, Bleached coral cover, Dead coral with algae, Rubble, Sandy fiat, Algal assemblage and other associated organisms, The sedimentation rate （mg cm^-2 d^-1） and coral coverage （%） were assessed during this study period. The average sedimentation rate was ranged between 0.27 and 0.89 mg cm^-2 d^1. The observed post bleaching recovery of coral cover was 21.1% at Port Blair Bay and 13.29% at Havelock Island. The mortality rate of coral cover due to this bleaching was estimated as 2.05% at Port Blair Bay and 9.82% at Havelock Island. Once the sea water temperature resumed back to the normal condition, most of the corals were found recovered.

Endemic Marine Benthic Invertebrates on the Brazilian Reef Ecosystems

Knowledge of the biodiversity of Brazilian reef ecosystems has expanded in recent years with several new species. Brazil is considered an important province because it has the only true reefs in the South Atlantic. This study identified the endemism of benthic invertebrate species of the Brazilian reefs. The reef coast is approximately 600 km long and extends from the state of Rio Grande do Norte to south coast of the Bahia state, with many coral and sandstone reefs near the shoreline and in the offshore zone, where the platform top remains exposed during low tides; and also on the Abrolhos region has isolated columns and offshore banks. Four offshore sites within the EEZ （Exclusive Economic Zone） were also included in this review. This study was based on the invertebrate benthic diversity existing on the northeastern coast, represented by Porifera with 450 spp, Cnidaria Scleractinia 16 spp and Echinodermata 51 spp. Of these, 102 species are endemic to Brazilian reefs, including Porifera with 86 spp （18,44%）, Cnidaria Scleractinia 8 spp （50%）, and Echinodermata 8 spp （2.93%）. The results reflect the recent increase in taxonomic studies, and identify a large number of endemic species among the benthic invertebrate fauna of the Brazilian reefs.

Blooming of bacteria and algae is a biokiller for mass-extinction of Devonian coral-stromatoporoid reef ecosystems

Studies of rock slices showed that there were many kinds of symbioses between bacteria and algae and corals-stromatoporoids in the coral-stromatoporoid reefs from the Devonian Ganxi section of Sichuan and the Dushan section of Guizhou in South China. They included encrustations, microborings, bioclaustration, etc. In the host corals-stromatoporoids invaded by bacteria and algae were many residues of dead soft issue in the infected parts, where the skeletal structures were injured. Therefore, we considered there were direct interactions between corals-stromatoporoids and bacteria and algae in coral-stromatoporoid reefs, which included that bacteria and algae blocked growth of corals-stromatoporoids and the latter had the ability of self-healing. And the bacteria and algae usually was the active side. In the Middle Devonian with normal seawater condition, corals and stromatoporoids had the ability to resist the invasion of bacteria and algae, and the host coral-stromatoporoids would not be killed; but in the Late Devonian with deterioration of seawater quality, the ability of bacteria and algae infection increased while corals-stromatoporoids' ability to resist infection declined, and therefore the host corals-stromatoporoids would be dead. Hence we suggested that the invading of bacteria and algae was a possible biokiller for mass-extinction of the Devonian coral-stromatoporoid reefs ecosystem. Beyond that, blooming of bacteria and algae and its triggering cumulative environmental effects played an important role in the reduction and extinction of metazoan in the Late Devonian. Furthermore, it can be used as a useful example to learn the trend and the reasons for the disease and decrease of modern coral reefs.

Black band disease as a possible factor of the coral decline at the northern reef-flat of Yongxing Island,South China Sea

Black band disease （BBD）, characterized by the Cyanobacterial dominated pathogenic consortium, is thought to play a key role in the global decline of the coral reef ecosystems. The present paper originally documents a case of BBD from Yongxing Island （Xisha Islands, South China Sea）, and further probes the reasons of this abnormal phenomenon. Prior to 2007, corals at northern reef-flat of Yongxing Isand were in healthy growth. Catastrophic coral mortality occurred between 2007 and 2008. The 16S rRNA gene sequencing and PCR amplification, with universally conserved primers, were applied to detect the conta- gious bacterial community of the microbial mat. The results demonstrated that six bacterial divisions constituted the clone libraries derived from the BBD mat, and that Cyanobacteria are the most diversely represented group that inhabit BBD bacteri- al mats, despite the fact that species in five others divisions （a-Proteobacteria, y-Proteobacteria, Bacteroidetes, Verrucomi- crobia and Actinobacteria） are also consistently diverse within the BBD mats of diseased coral. Other factors such as coral bleaching, typhoons, ocean acidification and crown-of-thorns starfish outbreaks, are not primarily responsible for the coral mortality within such a short time interval. The disaster expansion of BBD associated with Cyanobacterial blooms is a more likely mechanism impacting these coral reefs. Excessive human activity enhances the eutrophication of the marine water of the reefal region and may result in occurrence of the BBD.

Ecological-sedimentary zonations and carbonate deposition,Xiaodonghai Reef Flat,Sanya,Hainan Island,China

Modern fringing reefs are developed on the intertidal to subtidal area of Xiaodonghai bay, Sanya, Hainan Island. The reef flat extends several dozen meters toward the sea. Various ecological and sedimentary zonations can be distinguished, including, from land to sea, beachrocks, large massive corals, inner reef flat, outer reef flat, and fore-reef slope. The carbonate sediments and constituent hermatypic coral communities are different in these zones. The beachrocks are composed mainly of biological sands, including coral skeletons, algae, gastropods, bivalves, and benthic foraminifera. Quartz sands are less common in this zone. Carbonate diagenesis in beachrocks is characterized by early cementation. The fringing reef flat is progradationally developed toward the sea. Large massive corals grew in the zone next to the beachrocks. These corals are large, flat-toped, and autochthonous in the production of bioclastic grains and lime mud. Large and massive coral skeletons are surrounded by coral skeletal grains, bioclasts, and lime-mud sediments. The inner reef flat consists mainly of skeletons of branching corals that are covered by bioclasts and lime mud, and living corals are mostly massive in form. Statistical analysis of coral-community dynamics shows that the outer reef flat with strong waves is the most suitable place for hermatypic corals to flourish. There, the living corals are most densely distributed. Both massive corals and branching corals (e.g., Acropora corymbosa) are exceptionally healthy in this zone. Bioclasts and lime mud are washed out due to strong wave action. Microbial carbonates generally are deposited within cavities of the beachrocks and coral skeletal cavities and on the surfaces of bioclastic grains. The latter two types, however, are more common. Ecological-sedimentary zonations across the Xiaodonghai reef flat from beachrocks to outer reef flat are controlled by variations in wave strength and water energy. Microbial carbonates rarely developed on outer reef flat under strong wave action.