The Variation of Plankton Community Structure in Artificial Reef Area and Adjacent Waters in Haizhou Bay

Plankton are an important component of marine protected areas(MPAs),and its communities would require much smaller interpatch distances to ensure connection among MPAs.According to the survey from MPAs dominated by artificial reefs and adjacent waters(estuary area(EA),aquaculture area(AA),artificial reef area(ARA),natural area(NA)and comprehensive effect area(CEA))in Haizhou Bay in spring and autumn,we analyzed phyto-zooplankton composition,abundance and biomass,and correlation with hydrologic variables to gain information about the forces that structure the plankton.The results showed that the dominant zooplankton were copepods(spring,98.9%;autumn,94.2%),while the phytoplankton were mainly composed of Bacillariophyta(spring,61.8%;autumn,95.6%).The RDA results showed that temperature,salinity and depth highly associated with the distribution and composition of plankton species among the habitats than other factors in spring;temperature,Chla and DO had the strongest influence in autumn.The zooplankton in the ARA and AA ecosystems basically contained the same species as those in other habitats,and each habitat also exhibited a relatively unique combination of plankton species.The structures of the EA zooplankton in spring and the EA phytoplankton in both seasons were much different than other habitats,which may have been caused by factors such as currents and tides.We concluded that there exists similarity of the plankton community between artificial reef area and adjacent waters,whereas the EAs may be relatively independent systems.Therefore,these interaction between plankton community should be considered when designing MPA networks,and ocean circulations should be considered more than the environmental factors.

Catch organism assemblages along artificial reefs area and adjacent waters in Haizhou Bay

To better understand the community patterns mediated by connectivity in artificial reefs of coastal areas, it is necessary to understand the distribution and coexistence of organisms with artificial reefs area and adjacent waters. This study was conducted to examine main catches assemblages collected by trawls in Haizhou Bay,which included five habitats: the artificial reef area(AR), aquaculture area(AA), natural area(NA), estuary area(EA) and comprehensive effect area(CEA). The result shows that the total abundances of species in the five habitats were highly different(univariate PERMANOVA: P = 0.001, n = 24), but some species were also unique in their habitat(e.g. Scapharca subcrenata and Glossaulax didyma in AA). The body size distribution of specific species between habitats are different. For Collichthys lucidus, their body size in AR(14.63 cm ± 1.64 cm) and EA(14.3 cm ± 0.85 cm) is higher than that in NA(10.65 cm ± 1.64 cm), CEA(11.28 cm ± 1.85 cm) and AA(12.1 cm ±0.43 cm), which indicates the potential connection from AR to EA mediated by their adult population. We concluded that artificial reefs in AR can be considered key components that have the ability to support species assemblages in adjacent habitats. This study has implications for the conservation and monitoring of species assemblages in coastal areas in terms of that artificial reefs can be applied in different stages of habitat protection implementation and in different combinations of scenarios.

Flow Field Characteristics of Multi-Trophic Artificial Reef Based on Computation Fluid Dynamics

On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.

Coral reef ecological pump for gathering and retaining nutrients and exporting carbon:a review and perspectives

How coral reefs with high productivity and biodiversity can flourish in oligotrophic tropical oceans has inspired substantial research on coral reef ecosystems.Increasing evidence shows that similar to water in an oasis in the desert,there are stable nutrient supplies to coral reefs in oligotrophic oceans.Here,with emphasis on the fluxes of organic matter,we summarize at the ecosystem level(1)the multiple input pathways of external nutrients,(2)the storage of nutrients in reef organisms,(3)the efficient retaining and recycling of dissolved and particulate organic matter within coral reef ecosystems,(4)the distinctly high phytoplankton productivity and biomass inside and near oceanic coral reefs,and(5)the export of reef-related organic carbon to adjacent open oceans.These properties enable coral reefs to function as ecological“pumps”for gathering nutrients across ecosystems and space,retaining and recycling nutrients within the ecosystem,supporting high phytoplankton productivity,and exporting organic carbon to adjacent open oceans.Particularly,the high phytoplankton productivity and biomass make waters around coral reefs potential hotspots of carbon export to ocean depths via the biological pump.We demonstrate that organic carbon influx is vital for coral reef ecosystems’carbon budget and carbon export.The concept of the coral reef ecological pump provides a framework to improve the understanding of the functioning of the coral reef ecosystem and its responses to disturbance.Prospects of the coral reef ecological pump in coral reef studies are discussed in changing oceans driven by human activities and global change in the Anthropocene.

Sedimentary nitrogen dynamics in a coastal reef area with relatively high nitrogen concentration

The migration and transformation of nitrogen(N)in sediments play an important role in regulating the N concentration and nutrient structures in shallow seas.However,studies of sedimentary N dynamics are rarely focused on carbonate sediments,although these account for about 40%of the continental shelf area.Thus,the regulation mechanisms of the N dynamics in the carbonate sands of coral reefs are not clear.Taking the coral reef area of Weizhou Island,which has a relatively high N concentration,as the research object,we conducted a series of flow-through reactor experiments to investigate the fluxes of different N forms at the interface of sediment and seawater and their regulation mechanism by environmental factors.The fluxes of dissolved inorganic and organic N(DIN and DON)at different stations were-0.39-0.12 mmol/(m^(2)·h) and-0.18-0.39 mmol/(m^(2)·h),respectively.Denitrification(0.11-0.25 mmol/(m^(2)·h) was closely coupled to nitrification,which was limited by the availability of organic matter and its degradation product(i.e.,NH_(4)^(+)).Thus,the excessive NO_(3)^(-) might be reduced to NH4+by dissimilatory nitrate reduction to ammonium,rather than to N_(2) by denitrification.NO_(3)^(-) reduction peaked at intermediate advection rates(96 L/(m^(2)·h)) and flow path lengths(10 cm),but the release of DON also peaked at the same condition.In addition,climate warming would significantly affect sedimentary N dynamics at Weizhou Island.These results may help address the broader issue of the N cycle in coral reef eco systems under the dual pressure of climate warming and anthropogenic activities,and these results are beneficial to coral reef protection and local ecological management.

Meso-mechanical anisotropy and fracture evolution of reef limestones from the Maldives Islands and the South China Sea

Reef limestone is a biogenic sedimentary rock widely distributed in coral reef areas, acting as an important foundation for coast construction. Due to its special biogenic origin, reef limestone is different from conventional rocks both in terms of rock structure and mechanical properties. In this study, mesoscale uniaxial compression experiments with five different loading directions were conducted on two kinds of reef limestones from the Maldives Islands and the South China Sea, respectively. The real-time high-resolution videos and images of failure processes were recorded simultaneously to investigate the fracture evolution and fracture surface roughness of reef limestones. It demonstrated that the reef limestones belonged to extremely soft to soft rocks, and their uniaxial compressive strength (UCS) values fluctuated with high discreteness. The mesoscale mechanical properties of reef limestones were highly anisotropic and mainly controlled by pore structure. The occurrence of dissolution pores in reef limestone tended to intensify mechanical anisotropy. With the integration of the fracture initiation and propagation features of reef limestones, it is supposed that the intrinsic mechanism of anisotropy was probably attributed to the differences in coral growth direction and dissolution. Furthermore, the quantified fracture surface roughness was revealed to have a good consistency with density and UCS for the reef limestones from the South China Sea. The findings are helpful for providing theoretical and experimental references for engineering construction in coral reef areas.

An investigation of the morphodynamic change of reef islands under monochromatic waves

The persistence and habitability of coral reef islands in future extreme oceanographic conditions has received increasing attention in the recent decade,concerning that the sea level rise(SLR)and more frequent and intense storms in the context of global climate change are expected to destabilize those islands.Here,we conduct a set of wave-flume laboratory experiments focusing on the morphodynamic change of reef islands to varying ocean forcing conditions(wave height and SLR).Subsequently,a phase-resolving XBeach numerical model is adopted to simulate the monochromatic wave process and its associated sediment dynamics.The adopted model is also firstly validated by laboratory experimental results as reported in this study.It is then used to examine the impacts of island morphological factors(island width,island height,island location and island side slope)on the island migration.The combined laboratory/physical and numerical experiment outputs suggest that reef islands can accrete vertically in response to the sea level rise and the increased storminess.

Stressed Coral Reef Identification Using Deep Learning CNN Techniques

Deep learning is a machine learning technique that allows the computer to process things that occur naturally to humans.Today,deep learning techniques are commonly used in computer vision to classify images and videos.As a result,for challenging computer vision problems,deep learning provides state of the art solutions to it.Coral reefs are an essential resource of the earth.A new study finds the planet has lost half of its coral reefs since 1950.It is necessary to restore and prevent damage to coral reefs as they play an important role in maintaining a balance in the marine ecosystem.This proposed work helps to prevent the corals from bleaching and restore them to a healthy condition by identifying the root cause of the threats.In the proposed work,using deep learning CNN techniques,the images are classified into Healthy and Stressed coral reefs.Stressed coral reefs are an intermediate state of coral reef between healthy and bleached coral reefs.The pre-trained models Resnet50 and Inception V3 are used in this study to classify the images.Also,a proposed CNN model is built and tested for the same.The results of Inception V3 and Resnet50 are improved to 70%and 55%by tuning the hypermeters such as dropouts and batch normalisation.Similarly,the proposed model is tuned as required and obtains a maximum of up to 90%accuracy.With large datasets,the optimum amount of neural networks and tuning it as required brings higher accuracy than other methods.

三亚凤凰岛造礁石珊瑚迁移效果研究

造礁石珊瑚既是构成珊瑚礁生态系统中的关键功能生物,也是国家二级保护野生动物,其数量的快速衰退已引起了广泛关注,因此近年来我国对造礁石珊瑚以及珊瑚礁生态系统的保护正在逐步加强。海岸工程易对周边的珊瑚礁造成严重影响,实施保护性迁移是降低工程对造礁石珊瑚影响的重要手段。为研究海南热带海域造礁石珊瑚迁移方法以及迁移保护的效果,我们对三亚凤凰岛二期项目拆除工程影响海域内的造礁石珊瑚实施了保护性迁移及监测。迁移造礁石珊瑚个体共计16634株,包括鹿角珊瑚属、牡丹珊瑚属、滨珊瑚属等18属造礁石珊瑚种类。迁移个体分别迁移至鹿回头海域6210株与西岛海域10424株。迁移珊瑚采用了三种移植方法,分别为铆钉移植、小型移植礁体移植与直接摆放。在迁移至鹿回头和西岛两地8个月后,迁移珊瑚平均存活率均在80%以上,两地迁移珊瑚的总存活率为86.24%。调查的结果显示,铆钉移植的方法存活率最高,小型移植礁体和直接摆放的两种移植方法存活率稍低。迁移至西岛的珊瑚8个月平均生长了3.03cm,的增长率为23.31%,而鹿回头迁入的珊瑚平均生长了6.15cm,增长率为58.74%,高于迁移至西岛的珊瑚。迁移采用的三种移植方法的8个月的存活率均高于75%,并且珊瑚的生长速率较好,说明珊瑚适应迁入区环境。由以上结果来看,此次保护性迁移珊瑚数量多,涉及的珊瑚种类广,在迁移后经受过两次台风的影响,迁移结果具有一定的代表性。本研究中,珊瑚迁移的效果达到了保护受拆除工程影响的造礁石珊瑚的目的,可为未来的珊瑚迁移性保护提供重要经验。

《西沙群岛珊瑚岛(礁)地区岩土工程勘察标准》研究与编制

为适应和满足西沙群岛珊瑚岛(礁)工程建设的需要,使珊瑚岛(礁)岩土工程勘察有据可依,总结了西沙群岛岩土工程勘察项目实践经验和研究成果,通过资料收集、分析与研究,编制了《西沙群岛珊瑚岛(礁)地区岩土工程勘察标准》(DBJ46—060—2022)。介绍标准的编制背景、编制的工作流程、标准的主要内容和重点研究内容,探讨需要进一步研究的内容。

珊瑚礁生态系统固碳过程及储碳机制研究进展

珊瑚礁生态系统在全球碳循环和气候变化中发挥着重要作用。珊瑚礁生态系统是潜在的蓝色碳汇,我国珊瑚礁总面积约占全球的11%,每年的固碳量大约在3.5×10^(6)~4.5×10^(6)t之间。珊瑚礁生态系统的总储碳量非常巨大,同时珊瑚礁生态系统作为碳库在碳交易中具有非常大的潜在应用价值。文章综述了珊瑚礁生态系统中的固碳过程及储碳机制,包括碳酸盐泵、生物泵和微型生物碳泵,阐述了三种碳泵的研究进展。同时,针对目前研究存在的不足和问题,提出未来研究方向,以期为南海岛礁珊瑚礁生态系统的保护和管理提供科学依据。

岛礁风光柴储多能源独立微电网建模分析

岛礁多能源独立微电网是解决远海岛礁供电难题,确保岛上军民用电稳定及提高岛礁自然资源利用率的关键技术。传统岛礁独立微电网建模电源种类不够完备,交流母线应用较少。为此,建立了风、光、柴、储4种电源数学模型,在电力电子变换器中使用了基于扰动观察法的Boost升压电路与基于电网电压定向的矢量控制方式。系统模型中风、光、柴、储4种电源汇入交流母线,整体功率、电压趋于稳态。仿真结果表明:所构建的岛礁多能源独立微电网模型较为科学合理,可为开展岛礁多能源微电网健康管理等研究打下坚实基础。

珊瑚礁生态学研究现状和展望

珊瑚礁生态系统是海洋生态系统的重要组成部分,在维持海洋生态平衡和生物多样性上扮演着重要角色。本文通过文献检索手段,归纳了当前国际和国内珊瑚礁生态学领域的发展现状。国际上关注的主要方面包括全球变化与珊瑚礁生态系统、珊瑚共生关系的建立与维持、珊瑚礁生物系统发育与进化、珊瑚礁生物多样性及其物种分布格局、珊瑚礁生态系统保护与管理等;国内关注的主要方面包括全球变化与珊瑚礁生态系统、全球变化背景下的珊瑚–虫黄藻共生体、珊瑚共生关系多样性、人类活动与南海珊瑚礁生态系统、珊瑚礁生物多样性及其群落格局等。珊瑚礁生态学研究的未来发展趋势将更加注重全球变化背景下的珊瑚与珊瑚礁生态系统、珊瑚共生机制、边缘珊瑚礁以及珊瑚礁保护与修复。未来我国珊瑚礁生态学研究需提升全球视野,加强国内与国际合作,深入机制挖掘,完善系统研究,增强珊瑚礁保护与修复研究。

许氏平鲉幼鱼对人工鱼礁模型不同阴影情况的行为响应

阴影效应是影响人工鱼礁诱集效果的主要因素之一,为研究许氏平鲉(Sebastes schlegelii)对人工鱼礁不同阴影情况的行为响应,采用室内模拟实验方法,在实验水槽顶部固定光源,共设计3组实验:A组实验探究不同阴影面积的鱼礁模型对实验鱼的诱集效果;B组实验探究不放置鱼礁模型、悬挂不同开孔率顶板对实验鱼的诱集效果;C组实验探究阴影面积相同但开孔数量不同的鱼礁模型对实验鱼的诱集效果;对照组实验水槽中不放置鱼礁模型、不悬挂顶板。观察并记录许氏平鲉幼鱼(体长(5.06±0.09)cm,体质量(3.22±0.16)g)在水槽中的行为与分布特征。研究表明:3个实验组中许氏平鲉在鱼礁放置区域的出现率均显著高于对照组和其他区域;A组实验中,许氏平鲉在鱼礁放置区的平均出现率随着鱼礁阴影面积的增大而上升;B组实验中,许氏平鲉在顶板放置区的平均出现率显著高于对照组,但不同水平组之间差异不显著;C组实验中,开孔数为1时许氏平鲉在鱼礁放置区的平均出现率与开孔数为9时相近且高于开孔数为4和6时。研究结果表明,阴影面积越大的人工鱼礁对许氏平鲉的诱集效果越好,阴影面积相同时开孔数较多的人工鱼礁能够在提供良好庇护所的同时保证诱集效果。

人工鱼礁表面分离细菌形成单一生物被膜对厚壳贻贝稚贝附着的影响

为探讨存在于人工鱼礁表面的海洋细菌与贝类附着之间的互作关系,本研究从自然海域中的人工鱼礁表面上分离了9株海洋细菌,并分别构建单一细菌生物被膜,探索不同细菌种属形成的生物被膜特性与厚壳贻贝(Mytilus coruscus)稚贝附着之间的关系。结果显示,9株人工鱼礁表面细菌形成的生物被膜对厚壳贻贝稚贝附着的诱导活性存在显著差异,其中,Mesoflavibacter sp.2对稚贝附着的诱导活性最高,Phaeobacter sp.2的诱导活性最低。Sutcliffiella sp.1和Jeotgalibacillus sp.1的细菌密度与诱导活性呈显著正相关,Cytobacillus sp.1和Phaeobacter sp.2的细菌密度与诱导活性呈显著负相关。通过比较分析Mesoflavibacter sp.2和Phaeobacter sp.2生物被膜的蛋白质及多糖含量发现,生物被膜对厚壳贻贝稚贝附着的诱导活性与多糖含量呈显著负相关,与蛋白质含量呈正相关。本研究初步探索了人工鱼礁表面细菌形成的生物被膜对厚壳贻贝稚贝附着的影响,为后续在自然海区进一步解析人工鱼礁表面生物被膜与海洋无脊椎动物附着的互作关系具有重要理论研究意义,同时,对于人工鱼礁表面海洋生物附着机制的研究具有重要的实践价值。

生物礁对海平面变化的响应——基于黔南晚石炭世大型珊瑚礁的海平面变化幅度估算

晚古生代冰期是地质历史时期一个重要事件,由晚古生代冰期引起的海平面变化对该时期的生物礁系统产生深远影响.主要讨论了晚古生代冰期背景下生物礁对海平面变化的响应.生物礁随海平面变化表现为三种生长模式,即“放弃”“跟随”和“追赶”.以黔南地区格舍尔期大型珊瑚礁为例对黔南地区海平面变化幅度进行计算,认为黔南地区格舍尔期海平面上升(60±5)m,主要由冰川作用引起.根据扁平村珊瑚礁对格舍尔期黔南地区海平面变化幅度计算的误差来源主要为基底沉降以及古水深估算不精确.造礁珊瑚Fomitchevella的形态以及快速生长的特点揭示了黔南地区格舍尔期气候温暖、海平面上升且海侵快速的古环境条件.扁平村珊瑚礁的发育反映了全球气候变化和相关的海平面波动与冰期有关.

珊瑚礁海岸沉积物输运及珊瑚砂岛演变研究综述

珊瑚礁海岸沉积物的输运及珊瑚砂岛的演变研究在我国起步较晚,同时南中国海的珊瑚砂岛是我国重要的海洋空间资源,涉及国家领土主权的核心利益,开展这方面研究具有重要的学术价值和现实意义。综合分析了推移质和悬移质碳酸盐沉积物输运过程及其影响因素,重点介绍了短波、低频长波和海流对沉积物输运的驱动机制,以及粗糙珊瑚对沉积物的遮蔽效应。总结分析了珊瑚砂岛的动态演变规律及其影响因素,并重点介绍了珊瑚砂岛在长期海平面上升和短期风暴潮增强时的演变规律,并提出了今后研究需要关注的方向。

黄河口西南侧小岛河河口天然牡蛎礁的牡蛎种群结构

牡蛎礁是生态系统服务价值高、但退化最严重及受关注度最高的海洋生境之一,牡蛎礁修复亦成为国际海洋生态修复的热点。掌握牡蛎自然种群状况及动态变化是评估牡蛎礁修复效果的基础。目前,我国天然牡蛎礁的牡蛎种群状况相关的背景资料较为缺乏。在黄河口西南侧的小岛河河口新发现天然活体牡蛎礁,但该牡蛎礁曾被大规模的商业采捕,亟需推进针对性的保护和修复研究工作。基于2021年11月对该牡蛎礁开展的牡蛎种群生态调查,分析其种类组成、年龄结构及生长特征。结果显示:该牡蛎礁分布有近江牡蛎(Crassostrea ariakensis)和长牡蛎(Crassostrea gigas)。牡蛎礁上以活体牡蛎为主,死亡牡蛎壳体数仅占6.1%—6.7%。活体牡蛎的密度和生物量分别为(2811±778)个/m^(2)和(21.97±30.43)kg/m^(2),近江牡蛎较多,其密度和生物量分别占比55.7%和76.4%。近江牡蛎和长牡蛎的年龄分别介于0+—4+龄和0+—2+龄,它们都以壳高介于30—40 mm及壳质量<5 g的0+龄个体数量居多(>80%)。近江牡蛎的壳体形态参数均值都高于同龄组长牡蛎的相应值。两种牡蛎壳体均呈负异速增长,不同龄级的壳体延展方向不同。拟合von Bertalanffy生长方程得到,近江牡蛎和长牡蛎的渐近壳高分别为286 mm和173 mm,估算的拐点年龄分别为5.47龄和2.56龄,两种牡蛎的生长曲线分布存在极显著差异(P<0.001)。以上结果表明,小岛河河口的天然牡蛎礁的牡蛎自然种群资源较丰富,具有高密度、低龄和低死亡率等特点,有较好的活力和扩张潜力,有利于被采捕后的礁体的恢复。两种牡蛎中,近江牡蛎因其具有较高的生物量和较长的生长年龄,对礁体形成和扩繁可能更为重要。建议对该天然牡蛎礁及牡蛎种群开展周期>3年的原位保护、修复和连续监测计划。

鄂尔多斯盆地南缘麟游-淳化地区平凉组礁滩体沉积特征及分布预测

鄂尔多斯盆地南缘平凉期发育规模生物礁滩型储层,目前对该区的研究主要集中在礁滩体的类型、成因、区域演化等方面,而对礁滩体的地球物理预测尚未开展系统研究。为了提高礁滩体的预测精度,建立礁滩体储层地震预测方法,通过野外露头实地踏勘,结合岩心及分析测试等资料,对镶边台地高能环境下的生物礁滩发育特征进行研究。通过已知井的井震响应特征,建立礁滩体正演模型,同时开展流体活动性、地震纹理属性分析,形成研究区礁滩体储层的地震预测方法。结果表明:鄂尔多斯盆地南缘平凉组主要发育碳酸盐岩台地边缘-浅水陆棚沉积体系;礁滩体主要分布于台地边缘亚相,多期叠置;高亮体和纹理属性对礁滩体的预测效果最好,2种方法的联合应用大大提高了礁滩体预测精度。研究成果为台缘带礁滩体平面分布规律预测和鄂尔多斯盆地南缘平凉组礁滩体的勘探开发奠定基础。

四川盆地五百梯地区长兴组古地貌恢复及地震预测

四川盆地五百梯地区长兴组地层分布范围广、勘探潜力大,但存在礁滩储层厚度薄、礁滩体刻画难、演化规律不明显、非均质性强等问题,增加了储层预测的多解性。对此,从生物礁岩石学特征及储层特征研究出发,提出了生物礁储层的纵向发育规律和部位,并利用生物礁储层的地震异常特征,刻画礁滩体优质储层横向展布特征,并重点分析了古地貌对礁滩储层发育特征的关键性控制作用,最后结合古地貌恢复及储层反演等方法,对礁滩储层进行综合评价,并总结形成了长兴组礁滩体储层地震识别模式,降低了礁滩储层预测的多解性。研究发现,长兴组沉积前已形成了海槽雏形,长兴组早中期形成了台缘及台内二排礁区域高地貌基本格局,到长兴组沉积末期海槽特征明显,古地貌高部位是储层发育的最有利区域,优势储层主要集中在台缘外带及台内二排礁局部区域,该认识为四川盆地长兴组台内礁勘探提供了重要的依据及借鉴意义。