A risk assessment approach to contaminants in Port Curtis, Queensland, Australia     

Jones MA  Stauber J  Apte S  Simpson S  Vicente-Beckett V  Johnson R  Duivenvoorden L 《Marine pollution bulletin》2005,51(1-4):448-458

Port Curtis is one of Australia's leading ports for which substantial industrial expansion is proposed over the next decade. However, there has been little attempt to date to assess the extent of contamination in waters, sediments and biota or to characterize the potential impacts of contaminants on aquatic biota. Contaminants of potential concern to biota and human health were investigated in the Port Curtis estuary using a screening-level risk assessment approach. Dissolved metal concentrations in waters were below [ANZECC/ARMCANZ, 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Vol. 1. The Guidelines, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand] trigger values, suggesting low risk of these contaminants. In sediments, arsenic, nickel and chromium concentrations exceeded interim sediment quality guidelines-low (ISQG-low), but were also high in the reference zone suggesting a natural origin. Historical data on naphthalene in Harbour sediments showed that it was also of potential concern. Bioaccumulation of contaminants in a range of biota was also used as an indicator of contaminant exposure. Biota were generally enriched in metals and tributyltin, which was also elevated in water and sediments. Although not unique to Port Curtis, mercury in barramundi was identified as a potential risk to human health.  相似文献   

Quantitative evaluation of the performance of a permit auction system in reducing bycatch of sea turtles in the Hawaii Swordfish longline fishery     

Feng Tao Ning  Chao Zhang  Rod Fujita 《Marine Policy》2009

Many authors have suggested the use of a cap and trade auction system to help reduce bycatch—the incidental take of species by fishing gear targeting other species—of sea turtles in the Hawaii-based swordfish longline fishery. However, we know of no quantitative evaluations of the method. We present a simple mathematical model to serve as a framework to evaluate bycatch auction systems quantitatively. We conclude that cap and trade auction systems have the potential to reduce sea turtle bycatch by creating a financial incentive, while keeping permit costs down to 2–3% of total revenues. While stringent regulations aimed at conserving endangered sea turtles would still be essential, implementation of an auction for issuing transferable bycatch permits would likely enhance the economic efficiency of the fleet. Sea turtle mortality could be reduced further if a shrinking cap on total turtle mortality was introduced, taking advantage of the incentives for reducing turtle mortality that are introduced by the cap and trade auction system.  相似文献   

Quaternary over-elevated torrential channels. Characteristics and depositional significance: the Maresme model (Catalonia,NE Spain)     

Colombo  Ferran  Rivero  Lluis 《International Journal of Earth Sciences》2017,106(7):2489-2502

International Journal of Earth Sciences - Channel-levee deposits that occur in some large sand-dominated fluvial systems are commonly elevated above the surrounding floodplain. However, the...  相似文献   

Trace element concentrations in nesting flatback turtles (Natator depressus) from Curtis Island, Queensland, Australia     

Ikonomopoulou MP  Olszowy H  Limpus C  Francis R  Whittier J 《Marine environmental research》2011,71(1):10-16

The blood and eggs of the flatback turtle (Natator depressus) sampled when nesting at Curtis Island, Queensland, Australia. In the blood, zinc was present at the highest concentration of 151.15 ± 1.45 μg/L followed by copper (7.74 ± 0.09 μg/L). Lead was found only in some individuals. The measured trace elements in the blood were maternally transferred into the eggs. Other metals and metalloids detected in eggs were chromium, manganese, arsenic and selenium. Eggs showed a more complex trace element profile than blood, suggesting that they provided more representative tissues for determining maternal levels of trace element accumulation in N. depressus. Intra-clutch variation was over 15% for most of the studied trace elements suggesting one egg is not in sufficient to determine trace element accumulation within a clutch. Copper was the only element which was positively correlated with breeding age. Furthermore, no detectable levels of tin compound derivates were measured in N. depressus.  相似文献   

A new damage model based on non‐local displacements     

Antonio Rodríguez‐Ferran  Irene Morata  Antonio Huerta 《国际地质力学数值与分析法杂志》2005,29(5):473-493

A new non‐local damage model is presented. Non‐locality (of integral or gradient type) is incorporated into the model by means of non‐local displacements. This contrasts with existing damage models, where a non‐local strain or strain‐related state variable is used. The new model is very attractive from a computational viewpoint, especially regarding the computation of the consistent tangent matrix needed to achieve quadratic convergence in Newton iterations. At the same time, its physical response is very similar to that of the standard models, including its regularization capabilities. All these aspects are discussed in detail and illustrated by means of numerical examples. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

First results from the Very Small Array – III. The cosmic microwave background power spectrum     

Paul F. Scott  Pedro Carreira  Kieran Cleary  Rod D. Davies  Richard J. Davis  Clive Dickinson  Keith Grainge  Carlos M. Gutiérrez  Michael P. Hobson  Michael E. Jones  Rüdiger Kneissl  Anthony Lasenby  Klaus Maisinger  Guy G. Pooley  Rafael Rebolo  José Alberto Rubiño-Martin †  Pedro J. Sosa Molina  Ben Rusholme ‡  Richard D. E. Saunders  Richard Savage  An&#;e Slosar  Angela C. Taylor  David Titterington  Elizabeth Waldram  Robert A. Watson §  Althea Wilkinson 《Monthly notices of the Royal Astronomical Society》2003,341(4):1076-1083

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Source subtraction for the extended Very Small Array and 33-GHz source count estimates   总被引：1，自引：0，他引：1  

Kieran A. Cleary †  Angela C. Taylor ‡  Elizabeth Waldram  Richard A. Battye  Clive Dickinson §  Rod D. Davies  Richard J. Davis  Ricardo Genova-Santos  Keith Grainge  Michael E. Jones ¶  Rüdiger Kneissl  G. G. Pooley  Rafael Rebolo  José Alberto Rubiño-Martín  Richard D. E. Saunders  Paul F. Scott  An&#;e Slosar &#;  David Titterington  Robert A. Watson 《Monthly notices of the Royal Astronomical Society》2005,360(1):340-353

We describe the source subtraction strategy and observations for the extended Very Small Array (VSA), a cosmic microwave background interferometer operating at 33 GHz. A total of 453 sources were monitored at 33 GHz using a dedicated source subtraction baseline. 131 sources brighter than 20 mJy were directly subtracted from the VSA visibility data. Some characteristics of the subtracted sources, such as spectra and variability, are discussed. The 33-GHz source counts are estimated from a sample selected at 15 GHz. The selection of VSA fields in order to avoid bright sources introduces a bias into the observed counts. This bias is corrected and the resulting source count is estimated to be complete in the flux-density range 20–114 mJy. The 33-GHz source counts are used to calculate a correction to the VSA power spectrum for sources below the subtraction limit.  相似文献   

Possible usage of carbamide tar for creating artificial grounds with high sorption capacity     

I. A. Rod’kina  E. N. Samarin 《Moscow University Geology Bulletin》2009,64(6):390-393

Filtering a lead solution through model samples prepared on the basis of alluvial sand mixed with carbamide tar at the ratio of 1: 1 and 1: 2 resulted in a sorption capacity of 30 and 160 mg/g of sample, respectively. Direct and reverse potentiometric titration of carbamide tar with a 0.1 N Pb (NO₃)₂ solution showed that these results are due to the fact that the curing of carbamide tar in acidic conditions is accompanied by irreversible lead sorption, which is not extracted by conventional buffer solutions. Thus, lead atoms become tightly integrated in the polymer structure of the tar with N-Pb-N bonding.  相似文献   

Dynamical linkage of tropical and subtropical weather systems to the intraseasonal oscillations of the Indian summer monsoon rainfall. Part I: observations     

S. Ma  X. Rodó  Y. Song  B. A. Cash 《Climate Dynamics》2012,39(3-4):557-574

The Indian summer monsoon rainfall (ISMR) over the Western Ghats (WG) and the Bay of Bengal (BoB) is marked by the intraseasonal oscillations (ISOs) with preferred 10–20-day and 30–50-day bands. On the basis of pentad Climate Prediction Center Merged Analysis Precipitation and daily sea level pressure and winds at 850?hPa derived from European Center for Medium-range Weather Forecast reanalysis, we present the structure and evolution of the ISOs linked to the ISMR variations over the WG and the BoB and the associated anomalies of the atmospheric circulation using the approaches of wavelet analysis, bandpass filtering and composite analysis. This study reveals that the activities of both the intertropical convergence zone (ITCZ) and the western Pacific subtropical high (WPSH) contribute strongly to the structure and propagation of the ISOs on intraseasonal time scales. Northward development and propagation of the ITCZ plays a critical role in the northward-propagating ISOs, but not in the westward-propagating BoB 10–20-day ISOs. The latter ISOs may be linked, instead, to the activity of synoptic-scale weather systems to the east over the western tropical Pacific. The enhanced ITCZ in the tropical Indian Ocean plays a strong role in the sudden strengthening of the WPSH during the transition from the break to active phase of the 30–50-day ISOs. We find that the strong WPSH in the Asian summer monsoon season, with generally northward advance and eastward withdrawal, promotes the formation of a northwest to southeast tilted anomalous rainfall belt over the East Asian tropical summer monsoon region and the western tropical Pacific in the 30–50-day low-frequency band. Positive (Negative) elongated rainfall anomalies with an unbroken northwest-southeast tilt, strong easterly (westerly) anomalies in the tropical Pacific, and northward advance and eastward movement of strong (weak) WPSH are favorable for maintaining the eastward propagation of the 30–50-day ISOs in the Pacific. Daily high-resolution sea surface temperature obtained from the National Oceanic and Atmospheric Administration is used to explain the propagation features of the 10–20-day ISOs in the Indian Ocean.  相似文献   

Variations in seasonal rainfall in Southern Europe during the present century: relationships with the North Atlantic Oscillation and the El Niño-Southern Oscillation   总被引：2，自引：0，他引：2  

X. Rodó  E. Baert  F. A. Comín 《Climate Dynamics》1997,13(4):275-284

 Analysis of data from seventeen rainfall stations in the Iberian Peninsula, Balearic Islands and Northern Africa has revealed significant El Ni?o-Southern Oscillation (ENSO) signals in Europe. Both North Atlantic Oscillation (NAO) and Southern Oscillation (SO) exert an influence on Iberian climate, but at different temporal and spatial scales. Though most of the peninsula is under NAO influence in winter, some stations in the eastern region show no connection with this phenomenon. The same is found for ENSO, with a positively correlated region appearing in the eastern part of Spain, while the rest of the peninsula remains insensitive. The correlation between ENSO and Iberian rainfall has increased towards the end of the present century, with strong positive signals spanning over half of the area studied. The percentage of springtime variability due to ENSO has similarly increased, reaching up to 50% in certain areas. We also show how there are outstanding climatic sensors of these phenomena such as Lake Gallocanta, which manifests a positive response to ENSO while appears insensitive to NAO. Common long-term patterns are observed between SOI and an inferred lake level series, suggesting a constant influence of the low-frequency component of ENSO throughout the period considered. Lake drying phases every 14 years reflect the impact of this signal, approximately every four ENSO events. Received: 6 June 1996/Accepted: 30 October 1996  相似文献