Chemical composition of corals in Saudi Red Sea Coast

Three species of corals Stylophora pistillata, Lobophyllia corymbosa and Echinopora gemmacea were collected from Sharm Obhur to study their chemical composition. This information was important in the investigation of their metabolic pathways and their mode of feeding. The concentrations of amino acids in these species were 9.37, 21.35 and 3.09 mg·g⁻¹ dry weight of coral respectively. Plant pigments were highest in E. gemmacea followed by S. pistillata and then by L. corymbosa. Lipid concentrations in S. pistillata, L. corymbosa and E. gemmacea were 1.90, 8.58 and 1.32 mg·g⁻¹ of total coral respectively. The fatty acid methyl esters were analyzed in these species and the most abundant saturated acids were 16:0 and 18:0, while unsaturated acids included 16:1, 18:1 and 19:3. The carbohydrate concentrations were 559, 425 and 859 μg·g⁻¹ of total coral dry weight. Residual matter was 42.5, 32.8 and 41.39 per cent by weight of total coral. These data suggest a greater reliance on autotrophic feeding in E. gemmacea and S. pistillata and mostly heterotrophic feeding in L. corymbosa.     

南海北部冷泉区深水珊瑚的发现及其特征

冷水珊瑚也称为深水珊瑚, 在生物多样性、生态资源和科研价值等方面具有重要意义。文章对采自南海北部冷泉区的冷水珊瑚骨骼碎屑进行测定, 鉴定出冷水珊瑚2个种(Crispatotrochus sp.1和Crispatotrochus sp.2), 以及4个属[Balanophyllia (Balanophyllia)、Balanophyllia (Eupsammia)、Lochmaeotrochus和Enallopsammia]。测定的冷水珊瑚的δ¹³C为-7.36‰~-1.15‰, δ¹⁸O为-1.38‰~3.67‰, 与全球冷水珊瑚碳氧同位素组成相似, 但明显不同于南海暖水珊瑚、冷泉碳酸盐岩及低温热液成因碳酸盐岩的碳氧同位素组成。     

全球变暖背景下三亚湾上升流的冷水有利于珊瑚的生存

It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the background of global warming along the south coast of Hainan Island of China, satellite and in situ data are used to retrieve the information of the coral reef status and surrounding environmental factors. The results show that cool water induced by upwelling along the south coast of Hainan Island is found in the area every summer month, especially in the relatively strong El Ni?o years(2002–2003 and 2005). From the NOAA satellite data, degree heating week(DHW) index does not exceed 3 in Sanya Bay even in the relatively strong El Ni?o years. By comparison of a coral reef growth rate in the Sanya Bay with respect to El Ni?o events from 1957 to 2000, coral's growth rate is relatively greater during 1972, 1991–1994 and 1998 El Ni?o event. By analyzing the environmental factors, it is found that the cool water induced by upwelling may be the main reason for protecting corals from global warming effects.     

在闽东海域发现的石珊瑚的种类组成和分布

首次报道了闽东海域分布的3种石珊瑚,分别为造礁石珊瑚陀螺珊瑚（Turbinaria sp．）、非造礁石珊瑚猩红筒星珊瑚（Tubastrea coccinea Lesson）和1个珊瑚待定种,其中陀螺珊瑚和1个珊瑚待定种为中国新记录．珊瑚分布面积约3．24km2,主要呈零星斑块状分布在岛礁周围水深2—25m近岸岩礁区．2012年5～8月对闽东台山列岛和星仔列岛4km2范围内的55个岛礁近岸海域进行4个航次的调查表明,珊瑚的分布总体上南部的台山列岛海域分布数量多于北部的星仔列岛,海岛东部海域略多于西部．研究认为,闽东海域发现陀螺珊瑚说明其分布主要受台湾暖流的影响,揭示我国大陆沿岸造礁石珊瑚分布北缘可能扩展到台山列岛和星仔列岛．     

Mercury speciation in surface and deep waters of the Mediterranean Sea

Mercury speciation and its distribution in surface and deep waters of the Mediterranean Sea were studied during two oceanographic cruises on board the Italian research vessel URANIA in summer 2003 and spring 2004 as part of the Med Oceaneor and MERCYMS projects. The study included deep water profiles of dissolved gaseous Hg (DGM), reactive Hg (RHg), total Hg (THg), monomethyl Hg (MeHg) and dimethyl Hg (DMeHg) in open ocean waters. Average concentrations of measured Hg species were characterized by seasonal and spatial variations. Overall average THg concentrations ranged between 0.41 and 2.65 pM (1.32 ± 0.48 pM) and were comparable to those obtained in previous studies of the Mediterranean Sea. A significant fraction of Hg was present as “reactive” Hg (average 0.33 ± 0.32 pM). Dissolved gaseous Hg (DGM), which consists mainly of Hg⁰, represents a considerable proportion of THg (average 20%, 0.23 ± 0.11 pM). The portion of DGM typically increased towards the bottom, especially in areas with strong tectonic activity (Alboran Sea, Strait of Sicily, Tyrrhenian Sea), indicating its geotectonic origin. No dimethyl Hg was found in surface waters down to the depth of 40 m. Below this depth, its average concentration was 2.67 ± 2.9 fM. Dissolved fractions of total Hg and MeHg were measured in filtered water samples and were 0.68 ± 0.43 pM and 0.29 ± 0.17 pM for THg and MeHg respectively. The fraction of Hg as MeHg was in average 43%, which is relatively high compared to other ocean environments. The concentrations reported in this study are among the lowest found in marine environments and the quality of analytical methods are of key importance. Speciation of Hg in sea water is of crucial importance as THg concentrations alone do not give adequate data for understanding Hg sources and cycling in marine environments. For example, photoinduced transformations are important for the presence of reactive and elemental mercury in the surface layers, biologically mediated reactions are important for the production/degradation of MeHg and DGM in the photic zones of the water column, and the data for DGM in deep sea indicate the natural sources of Hg in geotectonicaly active areas of the Mediterranean Sea.     

南海北部滨珊瑚骨骼微生物侵蚀

微生物对珊瑚骨骼的侵蚀作用相对肉眼可见的大型生物侵蚀更加隐蔽, 研究也相对稀少, 国内更是空白。本文对采自涠洲岛、大亚湾以及西沙琛航岛的滨珊瑚骨骼切片在扫描电镜下开展微生物侵蚀研究。在涠洲岛和大亚湾的滨珊瑚骨骼切片中存在微生物侵蚀形成的“橘色条带”, 可能与当地水体富营养化有关, 而琛航岛的样品中则没有类似的条带。扫描电镜观察发现, 这些“橘色条带”为内生藻Ostreobium quekettii, 是一种热带珊瑚礁区常见的侵蚀微生物。O. quekettii侵蚀的珊瑚骨骼结构被破坏, 其厚度减小, 孔隙率提高了1.54%至6.76%、抗压强度下降了27.1%至51.2%, 使得珊瑚骨骼变得更加“疏松”, 且在整个骨骼次表面形成了一层“骨质疏松层”。该种侵蚀微生物扮演了“先行者”的角色, 使珊瑚更容易被大型生物侵蚀, 而大型生物侵蚀又会进一步促进微生物侵蚀, 该“正反馈效应”正好解释了在富营养化的南海北部发现的珊瑚骨骼内侵蚀加剧的现象。     

Resuspension of benthic fluff by tidal currents in deep stratified waters, northern North Sea

Suspended particulate matter (SPM) concentration and properties (particle size and settling velocity), water column and boundary layer dynamics were measured during a 60-d period at a site in 110 m water depth in the northern North Sea. The site was in stratified waters and measurements were made during September–November as the seasonal thermocline was progressively weakening. SPM concentration was low, c. 1 mg dm⁻³ in the surface mixed layer and maximum values of 2 mg dm⁻³ in the bottom mixed layer. The bottom layer was characterised by larger mean particle size. SPM signals in the two layers were decoupled at the start of the period, when the thermocline was strong, but were increasingly coupled as the thermocline progressively weakened. A spring-neap cycle of resuspension and deposition of SPM was observed in the bottom mixed layer. Bed shear stresses were too small to entrain the bottom sediment (a fine sand) but were competent to resuspend benthic fluff: threshold bed shear stress and threshold current velocity at 10 mab were 0.02–0.03 Pa. and 0.18 m s⁻¹, respectively. Maximum SPM concentration in the bottom layer preceded peak spring tide currents by 3 d. Simulation of fluff resupension by the PROWQM model confirms that this was due to a finite supply of benthic fluff: the fluff layer was stripped from the seabed so that fluff supply was zero by the time of peak spring flow. SPM was redeposited over neap tides. Fluff resuspension must have been enhanced by intermittent inertial currents in the bottom layer but unequivocal evidence for this was not seen. There was some resuspension due to wave activity. Settling velocity spectra were unimodal or bimodal with modal values of 2×10⁻⁴–2×10⁻³ mm s⁻¹ (long-term suspension component) and 0.2–5.7 mm s⁻¹ (resuspension component). The slowest settling particles remained in suspension at peak spring tides after the fluff layer had been exhausted. There was evidence of particle disaggregation during springs and aggregation during neaps.     

Ecohydrographic constraints on biodiversity and distribution of phytoplankton and zooplankton in coral reefs of the Red Sea,Saudi Arabia

An integral concept of ecological research is the constraint of biodiversity along latitudinal and environmental gradients. The Red Sea features a natural example of a latitudinal gradient of salinity, temperature and nutrient richness. Coral reefs along the Red Sea coasts are supported with allochthonous resources such as oceanic and neritic phytoplankton and zooplankton; however, relatively little is known about how the ecohydrography correlates with plankton biodiversity and abundance. In this article we present the biodiversity of phytoplankton and zooplankton in Red Sea coral reefs. Oceanographic data (temperature, salinity), water samples for nutrient analysis, particulate organic matter, phytoplankton and zooplankton, the latter with special reference to Copepoda (Crustacea), were collected at nine coral reefs over ~1500 km distance along the Red Sea coast of Saudi Arabia. The trophic state of ambient waters [as indicated by chlorophyll a (Chl a)] changed from strong oligotrophy in the north to mesotrophy in the south and was associated with increasing biomasses of Bacillariophyceae, picoeukaryotes and Synechococcus as indicated by pigment fingerprinting (CHEMTAX) and flow cytometry. Net‐phytoplankton microscopy revealed a Trichodesmium erythraeum (Cyanobacteria) bloom north of the Farasan Islands. Several potentially harmful algae, including Dinophysis miles and Gonyaulax spinifera (Dinophyceae), were encountered in larger numbers in the vicinity of the aquaculture facilities at Al Lith. Changes in zooplankton abundance were mainly correlated to the phytoplankton biomass following the latitudinal gradient. The largest zooplankton abundance was observed at the Farasan Archipelago, despite high abundances of copepodites, veligers (Gastropoda larvae) and Chaetognatha at Al Lith. Although the community composition changed over latitude, biodiversity indices of phytoplankton and zooplankton did not exhibit a systematic pattern. As this study constitutes the first current account of the plankton biodiversity in Red Sea coral reefs at a large spatial scale, the results will be informative for ecosystem‐based management along the coastline of Saudi Arabia.     

Vertical mesostructure of deep waters in the Black Sea

Studies of mesoscaleT, S characteristics of deep waters in the Black Sea carried out during 1978–1988 are generalized. Transformed lower Bosphorus waters are spread in the layer from 400 m to the bottom following density isosurfaces corresponding to this water. This is the way that interlayers ofT, S inversions are formed; their vertical thickness reaches 100–200 m in the Anatolian flow. The streamwise decrease of theT, S maxima and the location of isotherms in the cross-sections of these tongues permit the estimation of the order of the values of the coefficients of the vertical and horizontal turbulent diffusion.Translated by Mikhail M. Trufanov.     

Variations in architecture and cyclicity in fault-bounded carbonate platforms: Early Miocene Red Sea Rift,NW Saudi Arabia

The Early Miocene was a period of active rifting and carbonate platform development in the Midyan Peninsula, NW Saudi Arabia. However, there is no published literature available dealing with the detailed characterization of the different carbonate platforms in this study area. Therefore, this study aims to present new stratigraphic architectural models that illustrate the formation of different carbonate platforms in the region and the forcing mechanisms that likely drove their formation. This study identified the following features formed during active rifting: a) a Late Aquitanian (N4) fault-block hangingwall dipslope carbonate ramp, b) a Late Burdigalian (N7-N8) isolated normal fault-controlled carbonate platform with associated slope deposits, and c) a Late Burdigalian (N7-N8) attached fault-bounded platform with reef buildups, rimmed shelf developed on a footwall fault-tip within a basin margin structural relay zone that formed coinciding with the second stage of rifting. Variations in cyclicity have been observed within the internal stratigraphic architecture of each platform and also between platforms. High-resolution sequence stratigraphic analysis shows to be parasequences the smallest depositional packages (metre-scale cycles) within the platforms. The hangingwall dipslope carbonate ramp and the attached platform demonstrate aggradational-progradational parasequence stacking patterns. These locations appear to have been more sensitive to eustatic cyclicities, despite the active tectonic setting. The isolated, fault-controlled carbonate platform reveals disorganized stratal geometries in both platform-top and slope facies, suggesting a more complex interplay of rates of tectonic uplift and subsidence, variation in carbonate productivity, and resedimentation of carbonates, such that any sea-level cyclicity is obscure. This study explores the interplay between different forcing mechanisms in the evolution of carbonate platforms in active extensional tectonic regions. Characterization of detailed parasequence-scale internal architecture allows the spatial variation in syn-depositional relative base-level changes to be inferred and is critical for understanding the development of rift basin carbonate platforms. Such concepts may be useful for the prediction of subsurface facies relationships beyond interwell areas in hydrocarbon exploration and reservoir modeling activities.     

台湾北部近岸海域柳珊瑚体内金属累积的研究

自台湾北部和平岛沿岸海域及淡水河出海口海域，采得软木软柳珊瑚(ubergorgia suberosa)、扁刺柳珊瑚(Echinogorgia complexa)、网刺柳珊瑚(Echinogorgia reticulata)和1未定种柳珊瑚等4种柳珊瑚目样品。检测体内18种金属含量。其中以Ca、Zn、Cu、Al、Fe及Mn含量较高．体长较长的珊瑚。体内金属累积量则相对较高，尤其以Cu及Zn的趋势最为明确。经统计分析。显示4种珊瑚体内金属含量彼此间无群组相关性存在，呈现多变、无规则性的分布。本研究与大堡礁及委内瑞拉附近海域同一目珊瑚(Gorgonacea)中相同金属分析值进行比较结果Cd、Pb及Ni含量彼此差异不大，但Cu的含量则以台湾北部珊瑚体内较高。     

The tectonic style of the northern Red Sea

Multichannel seismic reflection profiles recorded in the northern Red Sea show structures that we interpret to be a result of the intrusion of uppermost Miocene salt. We believe that the evaporites are underlaid by attenuated continental crust and the flow of salt is due to renewed faulting of basement in the Pliocene when sea floor spreading began between latitudes 21°N and 15°30°N.     

New records of cold‐water coral sites and fish fauna characterization of a potential network existing in the Mediterranean Sea

New cold‐water coral (CWC) sites were recorded along the Apulian margin (Central Mediterranean). The species composition and depth distribution of CWCs were updated. A distribution of the CWC sites coincident with the course of the dense‐water masses that flow between the Southern Adriatic and Northern Ionian was confirmed. The faunal assemblages of five of these CWC sites were investigated and compared using experimental longlines during the spring–summer and autumn–winter seasons, between 2010 and 2014. Differences in ecological variables amongst the sites in each season were evaluated by means of a set of univariate and multivariate methods (analysis of variance, permutational multivariate analysis of variance, non‐metric multidimensional scaling). Although some differences were detected in relation to the different depths examined during spring–summer, the CWC sites showed similar features in terms of species richness and diversity as well as in the abundance of the same fish species (Galeus melastomus, Conger conger, Helicolenus dactylopterus, Merluccius merluccius, Phycis blennoides and Pagellus bogaraveo) most probably because of the distribution of adult specimens in structurally complex and heterogeneous habitats, which act as a potential ‘refuge network’ with respect to commercial fishing. The presence of maturing and mature individuals as well as post‐reproductive females indicates that these CWC sites also act as spawning areas, representing a potential ‘renewal network’ for the fish populations. The term ‘network’ used here refers to several similar subsystems (CWC sites) that play the same ecological role in a wider system (Apulian margin). These CWC communities need coherent conservation measures and management strategies according to the Ecosystem Approach to Fisheries.     

Patterns of summer vertical and horizontal currents in coastal waters of the northern Gulf of Aqaba, Red Sea

This study was focused on analysis of the horizontal and vertical current components with correspondence to tide variation, heat flux, seiches and relative backscatter intensity in coastal waters of the northern Gulf of Aqaba during the summers of 2001–2004. Spectrum analysis has shown eight distinguishable peaks of the tide measurements. In addition to semidiurnal and diurnal barotropic tides, signal periods of 8.13, 5.89–6.32 and 4.06 h were related to shallow water compound and overtides of the principal solar and lunar constituent and to seiches (second and third mode) generated in the Red Sea, whereas seiches of the first mode might enhance the semidiurnal tide signal. The shortest periods of 1.02–1.05, 0.50 and 0.36 h were related to seiches (first, second and third mode, respectively) generated in the Gulf of Aqaba. The spectrum analysis and cross-correlation tests of the horizontal and vertical current components and relative backscatter intensity suggested that the vertical motion at the diurnal period was either due to migration of zooplankton or to water convection. Both of which were of the same order as vertical motion induced by horizontal motions of water particles projected parallel on the bottom gradient line. On the other hand, semidiurnal and diurnal periods detected in the vertical currents were caused by the strong signal in the cross-shore current component, first mode seiches generated from the Red Sea and tide. This could be considered as an indicator of the dominant force influencing the currents, such as winds, thermocline depth, seiches and tidal forcing. A permanent convection during summer is likely to occur in the shallow coastal waters due to relatively high inclined bottom, high evaporation and blowing of dry air, as well as the observed dominance of the downward vertical currents in coastal waters.     

Dense water formation and circulation in the Barents Sea

Dense water masses from Arctic shelf seas are an important part of the Arctic thermohaline system. We present previously unpublished observations from shallow banks in the Barents Sea, which reveal large interannual variability in dense water temperature and salinity. To examine the formation and circulation of dense water, and the processes governing interannual variability, a regional coupled ice-ocean model is applied to the Barents Sea for the period 1948-2007. Volume and characteristics of dense water are investigated with respect to the initial autumn surface salinity, atmospheric cooling, and sea-ice growth (salt flux). In the southern Barents Sea (Spitsbergen Bank and Central Bank) dense water formation is associated with advection of Atlantic Water into the Barents Sea and corresponding variations in initial salinities and heat loss at the air-sea interface. The characteristics of the dense water on the Spitsbergen Bank and Central Bank are thus determined by the regional climate of the Barents Sea. Preconditioning is also important to dense water variability on the northern banks, and can be related to local ice melt (Great Bank) and properties of the Novaya Zemlya Coastal Current (Novaya Zemlya Bank). The dense water mainly exits the Barents Sea between Frans Josef Land and Novaya Zemlya, where it constitutes 63% (1.2 Sv) of the net outflow and has an average density of 1028.07 kg m⁻³. An amount of 0.4 Sv enters the Arctic Ocean between Svalbard and Frans Josef Land. Covering 9% of the ocean area, the banks contribute with approximately 1/3 of the exported dense water. Formation on the banks is more important when the Barents Sea is in a cold state (less Atlantic Water inflow, more sea-ice). During warm periods with high throughflow more dense water is produced broadly over the shelf by general cooling of the northward flowing Atlantic Water. However, our results indicate that during extremely warm periods (1950s and late 2000s) the total export of dense water to the Arctic Ocean becomes strongly reduced.     

北黄海冷水团对獐子岛微微型浮游生物分布的影响

Picoplankton distribution around the Zhangzi Island(northern Yellow Sea)was investigated by monthly observation from July 2009 to June 2010.Three picoplankton populations were discriminated by flow cytometry,namely Synechococcus,picoeukaryotes and heterotrophic prokaryotes.In summer(from July to September),the edge of the northern Yellow Sea Cold Water Mass(NYSCWM)resulting from water column stratification was observed.In the NYSCWM,picoplankton(including Synechococcus,picoeukaryotes and heterotrophic prokaryotes)distributed synchronically with extremely high abundance in the thermocline(20 m)in July and August(especially in August),whereas in the bottom zone of the NYSCWM(below 30 m),picoplankton abundance was quite low.Synechococcus,picoeukaryotes and heterotrophic prokaryotes showed similar response to the NYSCWM,indicating they had similar regulating mechanism under the influence of NYSCWM.Whereas in the non-NYSCWM,Synechococcus,picoeukaryotes and heterotrophic prokaryotes exhibited different distribution patterns,suggesting they had different controlling mechanisms.Statistical analysis indicated that temperature,nutrients(NO3–and PO43–)and ciliate were important factors in regulating picoplankton distribution.The results in this study suggested that the physical event NYSCWM,had strong influence on picoplankton distribution around the Zhangzi Island in the northern Yellow Sea.     

The impact of salt water inflows on the distribution of polycyclic aromatic hydrocarbons in the deep water of the Baltic Sea

Salt-water inflows into the Baltic Sea are important events for renewing the deep and bottom waters of the deep basins of the Baltic Sea. These events occur only at irregular intervals. The last strong event was in January 1993 followed by minor inflows in winter 1993/1994. As a result of these inflows, the deep water of the central Baltic basins was completely renewed.Based on extensive observations of polycyclic aromatic hydrocarbons (PAHs) in water, fluffy layer material and surface sediments between 1992 and 1998, the transformation of PAHs and the modification of their distribution in the Baltic deep water is discussed in connection with the spreading of the inflowing highly saline and oxygen-rich water along its pathway from the sills into the central basins. In the course of the inflows in 1993/1994, the PAH concentration in the deep water of the different basins increased significantly. The concentrations were elevated, at least by a factor of 2 and as much as seven to eight times (for the four-ring PAHs) compared to the previous and the following years. Two hypotheses for the causes were discussed: the inflowing salt water may have entrained more highly polluted surface water in the western Baltic Sea, or it may have entrained contaminated fluffy layer material or sediment particles along the route of transport.     

南海北部海区上层水体平均声速场的变化

对所收集到的南海北部海区的温度、盐度和深度历史资料进行了声速的计算、统计与分析,结果表明该海区上层水体的平均声速场有较明显的年际变化:表层声速的平面分布显示出沿岸水与外海水强弱交替变化的特征,声速等值线的走向几乎与岸线平行,等声速线的值自近岸向外海增加,大陆架外缘海区声速的水平梯度较大;下层声速的分布以环流和水体共同作用的形式出现,50m层声速平面分布的趋势除冬季与表层稍为相似外,其余季节与表层有明显的差别,春、夏季节50m层声速自西向东增加,而秋季与其表层分布相反,自近岸向外海减小;声速的垂直分布受海水升温与降温的影响显著,春、夏季表层海水升温,海表声速最大,声速自海表随深度的增加而减小;秋、冬季表层附近水层降温,声速稍偏低,普遍出现正梯度现象,最大声速移至表层以下的水层,这个深度随季节的改变而改变,随海区的不同而不同.该海区的平均声速有年波动现象,表层波幅最大,随深度的增加波幅变小,至100m水层其波动的位相几乎与表层相反.     

Turnover time of waters in a deep basin in the Aegean Sea

The Western Gulf is a basin in the Saronikos Gulf. Below about 100 m the water is almost stagnant, essentially isothermal (around 14°C) and it has practically uniform salinity. The level and the mechanism of enrichment in nutrients is discussed. The age of the water estimated from nutrient budget calculations is between one and eight years. The replacement time of water is similar to that found in the Santa Barbara basin, but different from those of the Cariaco Trench and the Black Sea.     

南海北部沉积物间隙水中营养盐研究

通过2004年9月对南海北部6个站位的采样分析,探讨了间隙水的营养盐含量及其空间分布特征,估算了沉积物-海水界面营养盐的扩散通量。结果表明,NH4-N含量为8.9—142.3μmol.L-1,是南海北部间隙水中营养盐的主要组分,占溶解态无机氮的比例范围为49.1%—75.2%。在平面分布上,NH4-N含量表现为近海高于远海,PO4-P则差别不大。NH4-N、NO3-N、NO2-N和PO4-P在沉积物-海水界面的平均通量分别为7.08、-0.61、-0.51、0.14μmol.(m2.d)-1。NH4-N、PO4-P主要是从沉积物向上覆水扩散,是底层水体营养盐的来源之一。