Coral assemblages and reef growth in the Commonwealth of the Northern Mariana Islands (Western Pacific Ocean)

Reef development varies considerably around the high, raised‐limestone islands of the Commonwealth of the Northern Mariana Islands (CNMI). Here we examine the modern assemblages at 30 sites for coral composition, colony density, colony size, and fidelity. We defined four reef types and hypothesize the presence of environmentally driven ecological stasis, whereby the environment continuously selects for coral species membership, defines colony sizes, and over time creates the noted reef types. Our results show that constructional spur‐and‐groove reefs supported significantly larger coral‐colony sizes and higher coral species richness compared with high‐relief interstitial framework, low‐relief incipient, and non‐constructional coral assemblages. Non‐constructional reefs supported much smaller coral colony sizes, despite similar population densities, and were consistently found in association with high wave exposure. The distinct coral assemblages found on interstitial framework and low‐relief incipient reefs were not affiliated with any wave exposure regime, but were located adjacent to large watersheds and on islands with unique geological history. These assemblages were nested within the spur‐and‐groove species pool. Overall, modern coral cover was well predicted by bathymetric slope and watershed size, while species richness was additively influenced by two proxies of pollution, suggesting the latter is better suited for establishing management targets. In contrast with previous studies that suggested modern assemblages were biologically controlled in the CNMI, we show reef assemblages and reef development are highly influenced by long‐term environmental forcing.     

The sheltering effect of the Balearic Islands in the hindcast wave field

The sheltering effect of the Balearic Islands in the hindcast wave field was studied for typical Mediterranean wave situations of Llevant, Tramuntana and Mestral and for mild conditions such as the Garbí and Ponent winds. For this purpose, a third generation wave model was applied to the Mediterranean Sea and different patterns of the sheltered areas were found for the various representative situations depending on the wind variability and on the magnitude of the wind speed. From the analysis it was concluded that the sheltered zones created during storms generally persist for short periods of time of the order of 6 h, possibly reaching a maximum of 12 h. In contrast with earlier results obtained for swell dominated ocean areas, it was observed that in this area, due to the short fetches the sea states are mainly local wind seas and thus the wave field behind the islands depends on the local wind.     

Spatial variability of soil nutrients in Punta Fort William,Greenwich Island,maritime Antarctic

This study aims to report baseline soil nutrients, specifically the organic carbon, nitrogen and phosphorus profile, in soil samples collected from Puntta Fort William on Greenwich Island in maritime Antarctic. Samples were collected along two transect lines during the early summer of 2008. Ward＇s method of hierarchical agglomerative clustering was employed to group the sampling points based on their physico-chemical properties. In this context, the soil samples can be grouped into three major clus- ters： （1） Samples with intensive biological activities, （2） samples from the area recently exposed by glacial retreat and （3） samples from barren and dried areas. Nutrient contents in Punta Fort William are driven by the intensity of biological activities as well as melt water from the Qnito glacier.     

Wavenumber and depth properties of temperature finestructure in the region around the Ryukyu Islands

INTRODUCTIONTheoceanicfinestructureintheEastChinaSea (ECS)Kuroshioregionhadbeenstudiedbyvariousresearchers.Fangetal.(1 988)studiedthefeaturesofthefinestructureinthesouthernshelfareaandtheKuroshioareaintheECSbyusingCTDdata .Baoetal.(1 996)analyzedsomefeaturesofthermohalinefinestructureandrevealeditsrelationwiththewatermassesandcurrentssysteminthenorthernECS .ButoceanicfinestructureintheeasternregionoftheKuroshiohassel dombeenstudied .Inthispaper,basedon 4 2CTDprofilesgatheredinsum…     

长山群岛海洋农牧化海域环境分区研究

海洋农牧化就是要在海域中,对贝、藻、鱼、虾类生物资源进行人工养殖、增殖以提高资源量。从捕天然生物资源转变成为以捕增养殖资源为主的生产方式。通过对长山群岛海域发展海洋农牧化的海域环境以及海水的理化因子等进行评价,并对该海域海水增养殖的发展状况、养殖品种及构成变化特征进行了分析,最后,应用主成份-聚类分析方法,将长山群岛海域环境划分为三个海洋农牧化区域,为因海制宜、合理布局海水增养殖生产提供科学依据。     

Comment on ‘García‐Santos G,Bruijnzeel LA. 2011. Rainfall,fog and throughfall dynamics in a subtropical ridge top cloud forest,National Park of Garajonay (La Gomera,Canary Islands,Spain). Hydrological Processes 25: 411–417’

A previous study aiming to characterize the water dynamics of a cloud forest in the Garajonay National Park (La Gomera) from measurements taken in a plot located in the upper part of a selected watershed within the park is here commented. Reported magnitudes of hydrological variables and conclusions based on them are in disagreement with those of numerous studies carried out previously at the same site. Large data dispersion and inapplicability of some of the hypothesis assumed are shown to invalidate most of the results. Copyright © 2011 John Wiley & Sons, Ltd.     

Biomarker characterisation and hydrous pyrolysis of bitumens from Tertiary volcanics, queen Charlotte islands, British Columbia, Canada

A number of bitumen samples have been recovered from vugs and fractures in outcropping Tertiary basalts of the Queen Charlotte Islands off the west coast of British Columbia, Canada. n-Alkanes and acyclic isoprenoids are not present and the polycyclic biomarker distribution of the four samples analyzed by GC and GC-MS has been altered. One sample contains no remaining recognizable biomarkers. Two bitumens were also obtained from Lower Jurassic potential source rocks, including one from the Sandilands Formation, which was considered previously to be the most likely source of the Tertiary bitumens. Although these two bitumens were also taken from outcrops, they are considerably less biodegraded. The Sandilands Formation bitumen contains 28, 30-bisnorhopanes and since these compounds were not detected in the Tertiary bitumens, there is no evidence from the initial results for a Sandilands Formation contribution to the hydrocarbons in the Tertiary basalts. The presence of 18α(H)-oleanane in the saturate fraction of two of the Tertiary bitumens from widely separated locations indicates that they are at least partially sourced from Tertiary organic matter.Because the distribution of biomarkers in some samples has been severely affected by biodegradation, the asphaltenes of the bitumens were hydrously-pyrolysed and the saturate fractions of the resulting pyrolysates analysed for possible additional information on the origin of the bitumens. The pyrolysates from the more degraded samples contain compounds not detected in the saturate fractions of the original bitumen and show some of the expected characteristics of the original non-degraded bitumen. However, the compounds most useful for correlation are not present in the pyrolysates apparently due to their non-incorporation into the kerogen macromolecule. Our results suggest that hydrous-pyrolysis of asphaltenes is of limited use in the correlation of biodegraded samples and in determining their origins.     

Statistical analysis and long-term prediction of seismicity for linear zones

The model of the Poisson point process is too vague for earthquake locations in space and time: earthquakes tend to cluster in middle distances and to repulse in large ones. The Poisson point model with variable density makes it possible to describe the tendency for clustering but does not reveal the periodicity of clusters. The author proposes the point-process model where locations of points are determined not by densities of point distribution, but by densities of interpoint differences distribution. In the model, a latent periodicity is revealed and used for prediction of a point process. In 1983, the point-process model prediction was made for the Kuril Islands for 1983–1987 and two signs of danger in time and location were determined. Then they were confirmed by strong earth-quakes. In 1989, a similar prediction was made for North Armenia. The Spitak earthquake in 1988 is clearly seen from the data of previous earthquakes.