Coral gas: oxygen production in millepora on the great barrier reef

Large volumes of a gas consisting of 69 percent molecular oxygen and 31 percent molecular nitrogen with trace amounts of carbon monoxide, carbon dioxide, and methane have been found trapped inside skeletons of the common hydrozoan Millepora. Volumes were low in the morning and reached a maximum by late afternoon. The oxygen was probably produced by the endolithic (boring) algae, with which the Millepora skeletons are very heavily infested. Oxygen production by endolithic algae in Millepora and in other substrates could influence estimates of reef productivity based on measurements of dissolved gases.     

Coral reef growth in the galapagos: limitation by sea urchins

The regular echinoid Eucidaris thouarsii is a conspicuous omnivore on coral bottoms in the Galápagos. Unlike Eucidaris in Panama and mainland Ecuador, Galápagos Eucidaris are large and abundant and graze heavily in the open on live corals day and night. These differences are probably due in large part to more intense predation by fishes on mainland compared with island urchin populations. An assessment of coral growth versus coral attrition from grazing shows that Eucidaris interferes with the establishment of pocilloporid reef frame and therefore reduces reef growth in the Galápagos.     

Localized dispersal and recruitment in great barrier reef corals: the helix experiment

To examine the problem of how far coral larvae disperse from their natal reef, coral recruitment densities were experimentally determined at distances up to 5 kilometers from a small, relatively isolated platform reef, Helix Reef, on the central Great Barrier Reef for 7 months. High concentrations of recruits, accounting for up to 40 percent of all recruitment, were found downstream of the reef in areas of high water residence time, suggesting that near-field(proximal) circulation has a profound influence on dispersal and recruitment of coral larvae. Coral recruitment declined logarithmically with distance from the reef, decreasing by an order of magnitude at radial distances of only 600 to 1200 meters. On an ecological time scale, advective dispersal of semipassive marine larvae with relatively short planktonic lives(minimally days) may be extensive, but success of recruitment is highly limited. Through evolutionary time, sufficient dispersal occurs to ensure gene flow to reef tracts hundreds or possibly thousands of kilometers apart. In the short term, however, coral reefs appear to be primarily self-seeded with respect to coral larvae.     

Horizontal plate motion: a key allocyclic factor in the evolution of the great barrier reef

The Great Barrier Reef complex of northeastern Australia thins dramatically and becomes younger from north to south. These variations are a consequence of the Cenozoic northward movement of the Indian-Australian plate. The temperate climatic conditions that applied off northeast Australia during the early Tertiary were progressively replaced by tropical conditions. The present-day south-to-north facies distribution along the eastern Australian continental margin mimics the Cenozoic vertical facies sequence through the northern part of the Great Barrier Reef region.     

Coral reef morphogenesis: a multidimensional model

Windward reef morphogenesis is a dynamic process directly controlled by the growth potential of dominant corals and coralline algae relative to wave energy and sea level rise. Moderate wave energy favors vertically rapid growth that is porous and uncemented; high wave energy favors slow but compact growth. Growth potentials of Caribbean and Indo-Pacific reefs are probably equivalent. Major differences are probably not due to biological or direct climatic factors but are in part related to differing patterns of sea level rise resulting from Holocene crustal adjustment. The nature and position of antecedent foundations developed by high interglacial and interstadial sea levels is especially critical and is largely controlled by regional tectonic factors, especially long-term subsidence.     

Coral chronometers: seasonal growth bands in reef corals

Autoradiagraphs and x-radiographs have been made of vertical sections through the centers of reef corals from Eniwetok. Radioactivity bands in the coral structure are caused by strontium-90 and are related to specific series of nuclear tests, thus making possible calculation of long-term growth rates. These data indicate that the cyclic variations in radial density revealed by x-radiography are annual.     

Coral reef death during the 1997 Indian Ocean Dipole linked to Indonesian wildfires

Geochemical anomalies and growth discontinuities in Porites corals from western Sumatra, Indonesia, record unanticipated reef mortality during anomalous Indian Ocean Dipole upwelling and a giant red tide in 1997. Sea surface temperature reconstructions show that although some past upwelling events have been stronger, there were no analogous episodes of coral mortality during the past 7000 years, indicating that the 1997 red tide was highly unusual. We show that iron fertilization by the 1997 Indonesian wildfires was sufficient to produce the extraordinary red tide, leading to reef death by asphyxiation. These findings highlight tropical wildfires as an escalating threat to coastal marine ecosystems.     

Jupiters great red spot: a free atmospheric vortex?

A simple hydrodynamic model yields steady-state solutions with many of the properties of the Great Red Spot and the neighboring belts and zones of Jupiter. No special forcing mechanism is necessary to maintain the circulation of the Spot. This is consistent with observations which indicate that the Great Red Spot and the zones have similar dynamic properties.     

Spatiotemporal patterns in the energy release of great earthquakes

For the past 80 years, the energy released in great strike-slip and thrust earthquakes has occurred in alternating cycles of 20 to 30 years. This pattern suggests that a global transfer mechanism from poloidal to toroidal components of tectonic plate motions is operating on time scales of several decades. The increase in seismic activity in California in recent years may be related to an acceleration of global strike-slip moment release, as regions of shear deformation mature after being reached by stresses that have propagated away from regions of great subduction decoupling earthquakes in the 1960s.     

Isotopic composition and origin of the red sea and salton sea geothermal brines

Abstract. Deuterium and oxygen-18 measurements show that the Red Sea and Salton Sea brines are the results of a single process, the leaching of sediments by surface water circulating downward to a geothermal reservoir. The Salton Sea brine is derived from local precipitation but the Red Sea brine originates 1000 kilometers south of its basin, on the shallow sill which controls the circulation of the Red Sea. On this sill sea water penetrates a thick evaporite sequence to a depth of 2000 meters, and, driven by its increased density relative to sea water, flows northward to emerge in the brine-filled deeps.     

Circular feature among dunes of the great sand sea, egypt

A circular crater, about 4 kilometers in diameter and located at 24.2 degrees N, 26.4 degrees E, was discovered in Landsat images among the linear dunes of the Great Sand Sea, Egypt. The crater has a sharp and crenulated rim crest, a terraced wall, a discontinuous inner structure (approximately 1.6 kilometers in diameter), and a few rim blocks. Its morphological and morphometric characteristics are similar to those of meteorite impact craters and other circular structures on the moon and the terrestrial planets. Because of its interaction with windblown sand, it is particularly comparable with craters on Mars.     

海州湾人工鱼礁海域鱼类和大型无脊椎动物群落组成及结构特征

为了解人工鱼礁区鱼类和大型无脊椎动物的数量变动及群落扰动情况,于2003、2004、2005和2007年采用底拖网对人工鱼礁区及邻近对照区进行了调查。结果表明:海州湾人工鱼礁区调查共鉴定鱼类和大型无脊椎动物96种,其中鱼类和节肢类是人工鱼礁区游泳生物的主要种类,分别占55.21%和35.42%,而软体类与棘皮类则分别占7.29%和2.08%。鱼礁区的生物种类数、生物量、丰富度和多样性指数除了呈现明显的季节变化外,年平均生物种类数、生物量、丰富度和多样性均高于对照区,鱼礁增殖效果明显。此外,通过ABC曲线分析发现:除投礁后第4年的鱼礁区春季和秋季外,投礁前和投礁后第1年、第2年的鱼礁区以及对照区各季节的鱼类和大型无脊椎动物群落结构都处于一个扰动状态。     

软颗粒饲料在真鲷网箱养殖中的应用研究

2010年5月于福建省连江县岗屿网箱养殖海区,采用2组不同干粉料原料添加小杂鱼配制而成的软颗粒饲料,与40%冰鲜小杂鱼进行了投喂真鲷对比试验,经过350～355 d的养殖,以小杂鱼投喂的对照组收获总重量372.00 kg,比实验组Ⅰ、实验组Ⅱ分别减少2.62%和8.37%,差异显著(P<0.05);对照组收获尾均重636.86 g,比实验组Ⅰ、实验组Ⅱ分别增重7.10%(P<0.05)和2.75%(P>0.05);对照组增重率为236.00%,比实验组Ⅰ、实验组Ⅱ分别降低3.75%(P>0.05)和10.84%(P<0.05);对照组特定生长率为0.492%,比实验组Ⅰ、实验组Ⅱ分别增加2.50%(P>0.05)、0.08%(P>0.05);对照组成活率为58.53%,比实验组Ⅰ、实验组Ⅱ分别降低了9.69%和11.91%,差异显著(P<0.05);对照组饵料系数为7.32,比实验组Ⅰ、实验组Ⅱ分别增加1.48倍和1.61倍,差异显著(P<0.05);对照组真鲷每增重1 kg所需饲料成本为19.77元,比实验组Ⅰ、实验组Ⅱ分别增加15.68%和8.51%,差异显著(P<0.05)。     

A unique symbiosis in the gut of tropical herbivorous surgeonfish (acanthuridae: teleostei) from the red sea

Herbivorous surgeonfish (Acanthurus species) in the Red Sea harbor gut symbionts that include bacteria, trichomonadid flagellates, and a peculiar putative protist that attains densities of 20,000 to 100,000 cells per milliliter of gut contents. The structure, mode of reproduction, and within-gut distribution of the latter are described. This may be the first report of an organism of this type and the first evidence of a consistent endosymbiosis in the gut of a herbivorous marine fish.     

Glacial and pluvial periods: their relationship revealed by pleistocene sediments of the red sea and gulf of aden

Oxygen isotope analyses of planktonic foraminifera from the Red Sea and Gulf of Aden indicate that during periods of maximum continental and polar glaciation in the late Pleistocene, the Red Sea was subject to strong evaporation. Between glacial maximums the salinity of the Red Sea was equal to or below that of the open ocean. This suggests that high-latitude glacial periods corresponded in time to interpluvial stages in the present-day desert belt of northern Africa, whereas high-latitude interglacial periods coincided with pluvial stages.