Trophic structure and functioning in a eutrophic and poorly flushed lagoon in southwestern Taiwan

Tapong Bay, a eutrophic and poorly flushed tropical lagoon, supports intensive oyster culture. Using the Ecopath approach and network analysis, a mass-balanced trophic model was constructed to analyze the structure and matter flows within the food web. The lagoon model is comprised of 18 compartments with the highest trophic level of 3.2 for piscivorous fish. The high pedigree index (0.82) reveals the model to be of high quality. The most-prominent living compartment in terms of matter flow and biomass in the lagoon is cultured oysters and bivalves, respectively. The mixed trophic impacts indicate that phytoplankton and periphyton are the most-influential living compartments in the lagoon. Comparative analyses with the eutrophic and well-flushed Chiku Lagoon and non-eutrophic tropical lagoons show that high nutrient loadings might stimulate the growth and accumulation of phytoplankton and periphyton and therefore support high fishery yields. However, net primary production, total biomass, fishery yields per unit area, and mean transfer efficiency of Tapong Bay were remarkably lower than those of Chiku Lagoon. The lower transfer efficiency likely results from the low mortality of cultured oysters and invasive bivalves from predation or the lower density of benthic feeders constrained by the hypoxic bottom water as a result of poor flushing. This might therefore result in a great proportion of flows to detritus. However, the hypoxic bottom water might further reduce the recycling of the entering detritus back into the food web. In contrast to many estuaries and tropical lagoons, poor flushing of this eutrophic tropical lagoon might induce a shift from detritivory to herbivory in the food web.     

A cluster perspective of the development of the deep ocean water industry

This paper explores the practical experiences of the cluster development of the deep ocean water (DOW) industry in the U.S., Japan, and Taiwan. The DOW industry is emerging as a new sector for utilizing diverse applications in the water, aquaculture, agriculture, pharmaceutical, cosmetic, tourism, and energy industries. Porter's perspective of the cluster is used to compare DOW commercialization in the three countries and to analyze their interactions with the economy, society, and technology. Using a multiple case study, this paper presents some implications beyond the geographical proximity, especially the triple-helix of academy, industry, and government within the borderless cluster. Finally, a comprehensive comparison among the three countries is examined to offer implications to managers and policy makers in the DOW industry.     

ISEE: Internet‐based Simulation for Earthquake Engineering—Part I: Database approach

An Internet‐based framework, named Internet‐based Simulation for Earthquake Engineering (ISEE) was developed to facilitate collaborative earthquake engineering experiments performed by multiple laboratories in a network environment. One of the approaches in the ISEE framework, named Database Approach, offers an easy way to perform multi‐site networked collaborative pseudo‐dynamic experiments. The Database Approach uses the Structured Query Language (SQL), a common and standardized computer language used in database management systems, for inter‐laboratory communications. Using the SQL protocol, it is easy to monitor the experiments' progress, access the data, as well as develop additional programs to expand the functions for a networked experiment. This approach offers consistency and durability of selected experimental data both during and after experiments. Two networked pseudo‐dynamic experiments were conducted to demonstrate the feasibility and expansibility of the Database Approach in ISEE. Copyright © 2007 John Wiley & Sons, Ltd.     

Toxicity identification evaluation (TIE) of pore water of contaminated marine sediments collected from Hong Kong waters

Marine sediment can function both as a source and as a sink of marine chemical contaminants. The toxicity of contaminated marine sediment can be assessed by toxic evaluation of its pore water, the inter-particle water of sediment, because toxicants in the pore water may be bioavailable to marine organisms. In this study, the toxicity identification evaluation (TIE) was performed to identify the major toxicants in the pore water of marine sediment collected in Hong Kong waters. In Phase 1 TIE, the suspected toxicants were characterized as anions or organic compounds that are either oxidizable or filterable in alkaline medium. In Phase 2 TIE, the suspected toxicants were identified as sulfide (S²⁻) based on the reduction of toxicity due to lowering of sulfide concentrations by experimental manipulations. The mass balance and spiking analyses in Phase 3 confirmed that S²⁻ was one of the major toxicants and that some non-toxic unknown compounds measured by LC–MS, which was removed by C18 solid phase extraction, enhanced the toxicity of S²⁻ in the pore water samples.     

Evaluation of Linear and Non-Linear Downscaling Methods in Terms of Daily Variability and Climate Indices: Surface Temperature in Southern Ontario and Quebec,Canada

We downscaled atmospheric reanalysis data using linear regression and Bayesian neural network (BNN) ensembles to obtain daily maximum and minimum temperatures at ten weather stations in southern Quebec and Ontario, Canada. Performance of the linear and non-linear downscaling models was evaluated using four different sets of predictors, not only in terms of their ability to reproduce the magnitude of day-to-day variability (i.e., “weather,” mean absolute error between the daily values of the predictand(s) and the downscaled data) but also in terms of their ability to reproduce longer time scale variability (i.e., “climate,” indices of agreement between the predictand's observed annual climate indices and the corresponding downscaled values). The climate indices used were the 90th percentile of the daily maximum temperature, 10th percentile of the daily minimum temperature, number of frost days, heat wave duration, growing season length, and intra-annual temperature range.

Our results show that the non-linear models usually outperform their linear counterparts in the magnitude of daily variability and, to a greater extent, in annual climate variability. In particular, the best model simulating weather and climate was a BNN ensemble using stepwise selection from 20 reanalysis predictors, followed by a BNN ensemble using the three leading principal components from the aforementioned predictors. Finally, we showed that, on average, the first three indices presented higher skills than the growing season length, number of frost days, and the heat wave duration.     

Impact of climate change on stream discharge and sediment yield in Northern Viet Nam

The purpose of this paper is to apply “Soil and Water Assessment Tool (SWAT)” model to assess the impacts of climate change on stream discharge and sediment yield from Song Cau watershed in Northern Viet Nam. Three climate change scenarios B1, B2, and A2; representing low, medium, and high levels of greenhouse gas emission, respectively, were considered in this study. The highest changes in stream discharge (up to 11.4%) and sediment load (15.3%) can be expected in wet season in 2050s according to the high emission scenario (A2), while for the low emission scenario the corresponding changes equal to 8.8% and 12.6%. The results show that the stream discharge is likely to increase in the future during the wet season with increasing threats of sedimentation.     

Using differential SAR interferometry to map land subsidence: a case study in the Pingtung Plain of SW Taiwan

Synthetic aperture radar (SAR) interferometry (InSAR) is a geodetic tool widely applied in the studies of earth-surface deformation. This technique has the benefits of high spatial resolution and centimetre-scale accuracy. Differential SAR interferometry (DInSAR) is used to measure ground deformation with repeat-pass SAR images. This study applied DInSAR and persistent scatterers InSAR (PSInSAR) for detecting land subsidence in the Pingtung Plain, southern Taiwan, between 1995 and 2000. In recent years, serious land subsidence occurred along coastal regions of Taiwan as a consequence of over-pumping of underground water. Results of this study revealed that the critical subsidence region is located on the coast near the estuary of Linpien River. It is also found that subsidence was significantly higher during the dry season than the wet season. The maximum annual subsidence rate of the dry season is up to −11.51 cm/year in critical subsidence region and the vertical land movement rate is much slower during the wet season. The average subsidence rates in wet and dry seasons are −0.31 and −3.37 cm/year, respectively. As a result, the subsidence rate in dry seasons is about 3 cm larger than in wet seasons.     

Solar wind plasma protrusion into the martian magnetosphere: ASPERA-3 observations

The ASPERA-3 experiment onboard the Mars Express spacecraft revealed, near the wake boundary of Mars, a spatially narrow, strip-like plasma structure composed of magnetosheath-like electrons and planetary ions. The peak electron energy often exceeds the peak energy at the bow shock that indicates a significant heating (acceleration) during the structure formation. It is shown that this structure is formed during efficient plasma penetration into the martian magnetosphere in the region near the terminator. The penetration of sheath electrons and their gradual heating (acceleration) is accompanied by a change of the ion composition from a solar wind plasma to a planetary plasma dominated by oxygen ions. A possible mechanism of plasma inflow to the magnetosphere is discussed.     

PAPPA: Primordial anisotropy polarization pathfinder array

The primordial anisotropy polarization pathfinder array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20° × 20° patch at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212, and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip transmission line to combine the phase modulation techniques used in radio astronomy with the sensitivity of transition-edge superconducting bolometers. Each switched circuit modulates the incident polarization on a single detector, allowing nearly instantaneous characterization of the Stokes I, Q, and U parameters. We describe the instrument design and status.     

A Borehole Test for Chlorinated Solvent Diffusion and Degradation Rates in Sedimentary Rock

We present a new field measurement and numerical interpretation method (combined termed “test”) to parameterize the diffusion of trichloroethene (TCE) and its biodegradation products (DPs) from the matrix of sedimentary rock. The method uses a dual-packer system to interrogate a low-permeability section of the rock matrix adjacent to a previously contaminated borehole and uses the borehole monitoring history to establish the pretest condition. TCE and its DPs are removed from the groundwater between the packers at the onset of the testing. The parameters estimated by fitting a radial diffusion model to the concentration history and borehole concentration data, also termed back diffusion, are the tortuosity factor and sorption coefficients of TCE and DPs in the rock matrix and the TCE and DP biodegradation rate coefficients in the borehole. We demonstrate the equipment design and the interpretive method using a borehole accessing the gray mudstone at a TCE contaminated site in the Newark Basin. In this test, both nonreactive (bromide) and reactive (trichlorofluoroethene) tracers are used to constrain the estimated parameters; however, the bromide tracer was not needed to estimate the parameters in this test. The parameters estimated from the field test are consistent with values measured independently in laboratory experiments using field samples of similar lithology. From the interpretation, we compute the TCE and DP concentration distributions in the rock matrix prior to the test to illustrate how the results can be used to enhance understanding of contaminant distribution in the rock matrix.