Estimation of nearshore groundwater discharge and its potential effects on a fringing coral reef

Radon (²²²Rn) measurements were conducted in Shiraho Reef (Okinawa, Japan) to investigate nearshore submarine groundwater discharge (SGD_nearshore) dynamics. Estimated average groundwater flux was 2-3 cm/h (maximum 7-8 cm/h). End-member radon concentration and gas transfer coefficient were identified as major factors influencing flux estimation accuracy. For the 7-km long reef, SGD_nearshore was 0.39-0.58 m³/s, less than 30% of Todoroki River’s baseflow discharge. SGD_nearshore was spatially and temporally variable, reflecting the strong influence of subsurface geology, tidal pumping, groundwater recharge, and hydraulic gradient. SGD_nearshore elevated nearshore nitrate concentrations (0.8-2.2 mg/l) to half of Todoroki River’s baseflow -N (2-4 mg/L). This increased nearshore Chl-a from 0.5-2 μg/l compared to the typically low Chl-a (<0.1-0.4 μg/l) in the moat. Diatoms and cyanobacteria concentrations exhibited an increasing trend. However, the percentage contributions of diatoms and cyanobacteria significantly decreased and increased, respectively. SGD may significantly induce the proliferation of cyanobacteria in nearshore reef areas.     

Sorption of heavy oil onto Jiaozhou Bay sediment

The sorption of heavy oil onto sediment collected from Jiaozhou Bay was studied in a series of kinetic and equilibrium experiments using NaCl solutions. The effects of temperature, salinity, and pH of the medium on sorption behavior were investigated.Sorption equilibrium of the heavy oil and sediment was established within 60 min. The process was shown to follow a pseudo-second-order kinetic rate model. The sorption rate decreased with increasing initial heavy oil concentration in the solution. Batch equilibrium experiments showed that the sorption isotherm could be described by the Freundlich model. The standard free energy change and enthalpy change at the temperatures studied (283, 288, 293, and 298 K) were negative. These findings indicated that the process was spontaneous and exothermic. Salinity, pH and temperature influenced sorption performance. Sorption was favored by higher concentrations of NaCl, by lower pH values and by lower temperatures.     

Assessment of sacrificial anode impact by aluminum accumulation in mussel Mytilus edulis: a large-scale laboratory test

Since the early 1960s, the application of aluminum alloy sacrificial anodes to mitigate marine corrosion has been well known. The aim of this work was to study aluminum bioconcentration in Mytilus edulis by an in vitro test performed in two tanks: the first containing non-contaminated water (NCW) and the second containing aluminum-contaminated water (CW) (530 μg L⁻¹) released by sacrificial anode. The mussels were collected and examined over a period of 8 weeks. A comparison between the aluminum concentrations in the digestive glands of mussels from the CW and NCW tanks shows that the highest value (1700 mg/kg d.w.) was found in the CW mussels collected after 13 days. In NCW, the mean aluminum concentration in digestive glands during the test was 281 mg/kg d.w. The rapid concentration decrease in digestive glands is probably due to the inhibition of filtering activity due to valve closure at the high concentration as well as the induction of the detoxification response.     

Modelling the biological half-life and seasonality of ¹⁴C in Fucus vesiculosus from the east coast of Ireland: implications for the estimation of future trends

Radiocarbon levels were recorded in Fucus vesiculosus samples collected on a monthly basis over a three-year period at a site on the east coast of Ireland. The resulting data was analysed using a numerical model which estimates the transit times from the Sellafield plant to the sampling location, and the mean availability time of ¹⁴C in seaweed. With the inclusion of a model parameter allowing for seasonal variability in uptake by the Fucus, good correlation was observed between the predicted and measured concentrations. Future temporal trends of ¹⁴C Fucus concentrations along the eastern Irish coastline were modelled with the application of three possible prospective discharge scenarios, predicting ¹⁴C Fucus concentrations to reduce to ambient background levels within 2.5-years of discharges being set to zero. Such projections may prove helpful in assessing the consequences of discharge management and policy making in the context of the OSPAR convention.     

Wetland conservation and sustainable coastal governance in Japan and England

Coastal wetlands present particular challenges for coastal governance and for the implementation of the Ramsar Convention, not least because coastal areas are focal points of human activity and of governance ambiguity. Through the evaluation of Ramsar delivery at both national and local levels in Japan and England, the relationship between Ramsar implementation and coastal governance was examined. In England, Ramsar status is primarily treated as a nature conservation designation which limits the wider opportunities inherent in the designation. In contrast, in Japan, the Ramsar Convention is used as a policy driver at the national level and as a leverage to encourage citizen engagement, economic benefit, and wetland conservation at the local level. It was concluded that through the implementation of the Ramsar Convention in important coastal wetland areas, significant steps can be taken towards delivering integrated approaches to coastal governance.     

Macrobenthos habitat mapping in a tidal flat using remotely sensed data and a GIS-based probabilistic model

This paper proposes and tests a method of producing macrofauna habitat potential maps based on a weights-of-evidence model (a probabilistic approach) for the Hwangdo tidal flat, Korea. Samples of macrobenthos were collected during field work, and we considered five mollusca species for habitat mapping. A weights-of-evidence model was used to calculate the relative weights of 10 control factors that affect the macrobenthos habitat. The control factors were compiled as a spatial database from remotely sensed data combined with GIS analysis. The relative weight of each factor was integrated as a species potential index (SPI), which produced habitat potential maps. The maps were compared with the surveyed habitat locations, revealing a strong correlation between the potential maps and species locations. The combination of a GIS-based weights-of-evidence model and remote sensing techniques is an effective method in determining areas of macrobenthos habitat potential in a tidal flat setting.     

ANN application for prediction of atmospheric nitrogen deposition to aquatic ecosystems

The occurrences of increased atmospheric nitrogen deposition (ADN) in Southeast Asia during smoke haze episodes have undesired consequences on receiving aquatic ecosystems. A successful prediction of episodic ADN will allow a quantitative understanding of its possible impacts. In this study, an artificial neural network (ANN) model is used to estimate atmospheric deposition of total nitrogen (TN) and organic nitrogen (ON) concentrations to coastal aquatic ecosystems. The selected model input variables were nitrogen species from atmospheric deposition, Total Suspended Particulates, Pollutant Standards Index and meteorological parameters. ANN models predictions were also compared with multiple linear regression model having the same inputs and output. ANN model performance was found relatively more accurate in its predictions and adequate even for high-concentration events with acceptable minimum error. The developed ANN model can be used as a forecasting tool to complement the current TN and ON analysis within the atmospheric deposition-monitoring program in the region.     

苏门答腊地震的构造控制因素探讨

最近,在苏门答腊俯冲带展开了一系列相互关联的海上及陆地研究,重点针对印度尼西亚2004年和2005年的板块边界地震破裂。这项由英国(英国苏门答腊联盟)、印度尼西亚、美国、法国和德国的科学家联手开展的研究计划旨在对这一边缘的地壳结构进行成像,以分析沿走向和上倾方向地震破裂     

88小时:美国地质调查局国家地震信息中心对2011年3月11日Mw9.0日本地震的响应

引言 2011年3月11日日本本州岛东海岸附近海域发生的M9．0地震（Tohoku earthquake,以下称“东日本大地震”——译者注）及其引发的海啸造成数以万计的人员死亡,造成的财产损失可能超过1万亿美元,这是有历史记录以来最严重的自然灾害之一。     

Braiding process and bank erosion in the Brahmaputra River

The present work explores relations between stream power,braiding intensities and bank erosion in certain stretches of the Brahmaputra River.In this paper,an objective approach is presented to enable quantitative assessment of spatio-temporal behaviour of channel braiding process of the Brahmaputra River by using the Plan Form Index and corresponding estimation of stream power to establish a behavioural pattern of variability of potential energy expenditure.The braiding index is compared for discrete years to understand the morphological behaviour.Subsequently,a real time estimation of stream power for certain stretches of Brahmaputra River is done in order to analyse its variability in braiding intensity and bank erosion.The paper presents the dynamic behaviour of the channel pattern of the Brahmaputra River System in Assam valley of India over a time span of 18 years.The procedure addresses the selection of input parameters from digital satellite images,comprising scenes for the years 1990,1997 and 2007 with specific dates,from Dhubri near Indo-Bangladesh Border to Upper Assam.Deployment of GIS technique has been made to extract the required parameters to derive Plan Form Indices for the entire study reach.Stream power estimation is done for corresponding latest floods and for corresponding dates of image scenes.The study indicated that due to consistent aggradation of riverbed inducing temporal declination of stream power,there is an occurrence of wide spread braiding.This in turn incurs substantial yearly land loss due to bank erosion,caused by flow concentrations due to temporal evolution of multiple channels in the Brahmaputra River.