Toxicity comparison of biosurfactants and synthetic surfactants used in oil spill remediation to two estuarine species   总被引：1，自引：0，他引：1  

Edwards KR  Lepo JE  Lewis MA 《Marine pollution bulletin》2003,46(10):1309-1316

The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbiologically produced surfactants were determined and compared in this study for the estuarine epibenthic invertebrate, Mysidopsis bahia and the inland silverside, Menidia beryllina. The toxicities of the surfactant were determined in standard laboratory static and static-renewal tests of 4-7 d duration. Results were specific to the surfactant, response parameter and test species. The LC50 values (nominal concentrations) for M. bahia ranged from 3.3 mg/l (Triton X-100) to >1000 mg/l (PES-61) and 2.5 mg/l (Triton X-100) to 413.6 mg/l (PES-61) for M. beryllina. Chronic first-effect concentrations (mg/l) for the six surfactants ranged from 2.3 to 465.0 (M. beryllina) and 1.0 to >1000.0 (M. bahia) based on reductions in growth and fecundity. Few generalizations could be made concerning the results due to their variability but M. bahia was generally the more sensitive species and the toxicities of the biosurfactants were intermediate to those of the synthetic surfactants.  相似文献   

Dissolved Pb Concentrations and Stable Pb Isotope Ratios in the Ulleung Basin,East/Japan Sea     

Choi  Seonghu  Choi  Man-Sik  Joe  Dongjin  Park  Sojung  Kim  Jinwoo  Ra  Kongtae  Kim  Intae  Kim  Kyung-Tae  Lee  Kyoung-Seok  Lim  Jean-Sun 《Ocean Science Journal》2022,57(3):436-450

Ocean Science Journal - The spatial distributions of dissolved lead (Pb) concentrations and stable Pb isotope ratios in the Ulleung Basin, East/Japan Sea, were investigated to identify the Pb...  相似文献   

Status of the major lobster fisheries in India     

E.V. Radhakrishnan  V.D. Deshmukh  Mary K. Manisseri  M. Rajamani  Joe K. Kizhakudan  R. Thangaraja 《新西兰海洋与淡水研究杂志》2013,47(3):723-732

Commercial exploitation of lobsters from the Indian seas began in the 1950s. Annual landings have been declining from a peak of 4075 t in 1985 to 1364 t in 2002. Major fisheries were located on the north‐west, south‐west, and south‐east coasts. Among the 12 species recorded, only four species of spiny lobsters (three littoral and one deep sea) and one species of slipper lobster are commercially important. At Kayalpattinam and Tharuvaikulam, on the south‐east coast, lobster landings sharply declined for the gill‐net fishery. Of the two species that contributed to the fishery, Panulirus ornatus and Panulirus homarus, the latter has been more affected owing to high vulnerability to fishing activities. Catch composition analysis of the trammel‐net fishery showed that 35% of the landings consisted of P. homarus in the size range of 23–50 mm carapace length. On the north‐west coast, the spiny lobster Panulirus polyphagus and the slipper lobster Thenus orientalis are incidentally caught in trawl nets. However, the fishery for T. orientalis in the waters off Mumbai lasted only up to 1994. Large‐scale exploitation of spawning females, which formed 60% of the total catch, might have been detrimental to the recruitment process resulting in rapid decline and total collapse of the fishery. Abundance of P. polyphagus reached its maximum during September, constituting 23% of the average annual landing during 1988–2002. A high exploitation ratio (>0.7) indicated over‐fishing of the stock. Repeated spawning and high annual egg production are probably responsible for sustaining the stock, despite over‐exploitation. Major problems confronting the resource management of the multi‐gear and multi‐species lobster fisheries in India are discussed. An operational project, involving fisher community, has been taken up for creating awareness of the need for sustainable exploitation of the resource. Regulatory measures, such as closure of the fishery during the peak of the breeding season, ban on trammel‐net, mandatory release of egg‐bearing lobsters, and establishment of lobster sanctuaries are suggested to the State Governments for implementation.  相似文献   

Establishing boundary classes for the classification of UK marine waters using phytoplankton communities   总被引：2，自引：0，他引：2  

Devlin M  Best M  Coates D  Bresnan E  O'Boyle S  Park R  Silke J  Cusack C  Skeats J 《Marine pollution bulletin》2007,55(1-6):91-103

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Hydroclimatic river discharge and seasonal trends assessment model using an advanced spatio-temporal model     

Srinivas  R.  Singh  Ajit Pratap  Dhadse  Kunal  Magner  Joe 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(2):381-396

Stochastic Environmental Research and Risk Assessment - Climatic changes have a significant impact on the hydrologic behavior of a river especially its discharge. Sustainable management of water...  相似文献   

An alternative method for interpreting jet erosion test (JET) data: part 1. Theory          下载免费PDF全文

Calvin W. Rose  Jon M. Olley  Arman Haddadchi  Andrew P. Brooks  Joe McMahon 《地球表面变化过程与地形》2018,43(3):735-742

The jet erosion test (JET) is a widely applied method for deriving the erodibility of cohesive soils and sediments. There are suggestions in the literature that further examination of the method widely used to interpret the results of these erosion tests is warranted. This paper presents an alternative approach for such interpretation based on the principle of energy conservation. This new approach recognizes that evaluation of erodibility using the jet tester should involve the mass of soil eroded, so determination of this eroded mass (or else scour volume and bulk density) is required. The theory partitions jet kinetic energy flux into that involved in eroding soil, the remainder being dissipated in a variety of mechanisms. The energy required to erode soil is defined as the product of the eroded mass and a resistance parameter which is the energy required to entrain unit mass of soil, denoted J (in J/kg), whose magnitude is sought. An effective component rate of jet energy consumption is defined which depends on depth of scour penetration by the jet, but not on soil type, or the uniformity of the soil type being investigated. Application of the theory depends on experimentally determining the spatial form of jet energy consumption displayed in erosion of a uniform body of soil, an approach of general application. The theory then allows determination of the soil resistance parameter J as a function of depth of scour penetration into any soil profile, thus evaluating such profile variation in erodibility as may exist. This parameter J has been used with the same meaning in soil and gully erosion studies for the last 25 years. Application of this approach will appear in a companion publication as part 2. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

An alternative method for interpreting JET erosion test (JET) data: Part 2. Application          下载免费PDF全文

Arman Haddadchi  Calvin W. Rose  Jon M. Olley  Andrew P. Brooks  Joe McMahon  Timothy Pietsch 《地球表面变化过程与地形》2018,43(3):743-754

This paper reports the results of jet tester experiments on soil samples of uniform properties which allow quantitative application of the new theory proposed in part 1 of these publications. This theory explores the possibly that a more adequate indicator of soil erodibility may be obtained by using the mass (and so volume) of soil eroded by the jet and the depth of scour penetration, rather than by using penetration depth alone, as assumed in the commonly‐used data interpretation method. It is shown that scour geometry can be well described using a generalized form of the Gaussian function, defined by its standard deviation and maximum depth. Using a published expression for jet kinetic energy flux, the new theory divides this flux into that used to erode soil, and the remainder which is dissipated in a variety of ways. Jet experiments on a specially‐prepared uniform soil sample are reported which provide the key to determining the spatial variability in the profile resistance to erosion offered by field soils. This resistance is expressed in the work required to erode unit mass of soil, denoted as J (in J/kg). The paper also gives results obtained on the profile variation in J for jet tests carried out at riverine sites on the upper Brisbane River, Queensland, Australia. As expected in most natural soil profiles, the results show an increase in J with depth in the profile. The soil resistance (J) is compared to the traditional interpretation of soil erodibility, (k_d). The graphical comparison of these two indicators illustrates the inverse type of relationship between them which is expected from their respective definitions, but this relationship is associated with significant scatter. Possible reasons for this scatter are given, together with comments on jet tester experience in a wide variety of soil types. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Crustal structure of the deepwater west Niger Delta passive margin from the interpretation of seismic reflection data     

Sepribo Eugene Briggs  Joe Cartwright  Richard J. Davies 《Marine and Petroleum Geology》2009

The interpretation of 2D and 3D seismic reflection data complemented with gravity data allows the crustal architecture of the deepwater west Niger Delta passive margin to be defined. The data show that the area is underlain by oceanic crust that is characterised by a thickness of 5–7 km and by internal reflectivity consisting of both dipping and sub-horizontal reflectors. Some of the dipping reflections can be traced up to the top of the basement where they offset it across a series of minor to major thrust faults. Other internal reflections are attributed to extensional shear zones and possibly due to intrusions in the lower crust. The Moho can be correlated as a discrete reflection over >70% of the study area. It is generally smooth, but localised relief of up to 1 km is observed. The southeastern part of the study area is dominated by a zone of SW–NE striking basement thrusts.  相似文献   

The upper ocean response to a moving typhoon   总被引：1，自引：0，他引：1  

Yaling Tsai  Ching-Sheng Chern  Joe Wang 《Journal of Oceanography》2008,64(1):115-130

The upper ocean response to the translation speed of typhoons is studied using a three-dimensional primitive equation model. Similar models studied previously have applied stability criteria rather than the diffusion term to simulate the vertical mixing process. This study retains the diffusion term and uses the level-2 turbulence closure scheme to estimate the vertical eddy viscosity. The model results indicate that in the forced period, the mixed-layer temperature decrease is greater for a slow-moving storm due to stronger upwelling caused by the longer residence time. A fast-moving storm can attain a similar cooling intensity in the wake period if its residence time allows the wind to resonate with the current. The significant downward momentum diffusion and advection in the first few inertial periods of these events leads to strong, persistent inertial pumping throughout the upper ocean in the wake period. The mixed layer is further cooled by turbulent mixing supported by vertical current shears. Meanwhile, the upper thermocline exhibits a compensating temperature increase. The vertical transfer magnitude and penetration scale are smaller in the slow-moving case, when the inertial motion decays rapidly. The model results also indicate that the dominant cooling process can be inferred from the non-dimensional storm speed. However, this value may be misleading for rapidly moving storms in which the current response is so distant from the storm that little wind work is performed on the ocean.  相似文献   

MTD distribution on a ‘passive’ continental margin: The Espírito Santo Basin (SE Brazil) during the Palaeogene     

Davide Gamboa  Tiago Alves  Joe Cartwright  Pedro Terrinha 《Marine and Petroleum Geology》2010

Mass-wasting on the Brazilian margin during the Mid-Eocene/Oligocene resulted in the accumulation of recurrent Mass Transport Deposits (MTDs) offshore Espírito Santo, SE Brazil. In this paper, we use three-dimensional seismic data to characterize a succession with stacked MTDs (Abrolhos Formation), and to assess the distribution of undeformed stratigraphic packages (i.e. turbidites) with reservoir potential separating the interpreted MTDs. High-amplitude strata in less deformed areas of MTDs reflect their internal heterogeneity, as well as possible regions with a higher sand content. Separating MTDs, turbiditic intervals reach 100 ms Two-Way Travel Time (TWTT), with thicker areas coincident with the flanks of growing diapirs and areas of the basin where mass-wasting is less apparent. Turbiditic strata laterally grade into, or are eroded by MTDs, with transitional strata between MTDs and turbidites being also influenced by the presence of diapirs. MTDs show average thickness values ranging from 58 to 82 ms TWTT and constitute over 50% of Eocene-Oligocene strata along the basin slope. Low average accumulations of 58 ms TWTT in areas of high confinement imposed by diapirs suggest sediment accumulation upslope, and/or bypass into downslope areas. This character was induced by the high sediment input into the basin associated with coastal erosion and growth of the Abrolhos volcanic plateau. Our results suggest that significant amounts of sediment derive from the northwest, and were accumulated in the middle-slope region. Interpretations of (palaeo)-slope profiles led to the establishment of a model of margin progradation by deposition of MTDs, contrasting with the retrogressive erosional margins commonly associated with these settings.  相似文献