Marine renewable energy: The ecological implications of altering the hydrodynamics of the marine environment     

Mark A. Shields  David K. WoolfEric P.M. Grist  Sandy A. KerrA.C. Jackson  Robert E. HarrisMichael C. Bell  Robert BeharieAndrew Want  Emmanuel OsalusiStuart W. Gibb  Jonathan Side 《Ocean & Coastal Management》2011,54(1):2-9

Many countries now recognise the need for mitigation of climate change induced by human activities and have incorporated renewable energy resources within their energy policy. There are extensive resources of renewable energy within the marine environment and increasing interest in extracting energy from locations with either large tidal range, rapid flow with and without wave interaction, or large wave resources. However, the ecological implications of altering the hydrodynamics of the marine environment are poorly understood. Ecological data for areas targeted for marine renewable developments are often limited, not least because of the considerable challenges to sampling in high energy environments. In order to predict the scale and nature of ecological implications there is a need for greater understanding of the distribution and extent of the renewable energy resource and in turn, of how marine renewable energy installations (MREIs) may alter energy in the environment. Regional ecological implications of a MREI need to be considered against the greater and global ecological threat of climate change. Finally, it is recommended that the identification of species and biotopes susceptible to the removal of hydrokinetic energy could be a suitable strategy for understanding how a MREI may alter flow conditions.  相似文献   

Metal dynamics in an Antarctic food chain     

Nygård T  Lie E  Røv N  Steinnes E 《Marine pollution bulletin》2001,42(7):598-602

The concentrations of copper, zinc, cadmium, selenium and mercury were determined in eggs, muscle, liver, kidney and stomach content of nestilings and adults of the Antarctic petrel, Thalassoica antarctica, and its predator, the south polar skua, Chataracta maccormicki, from Svarthamaren, Dronning Maud Land, Antarctica. The dominant food of the petrels is krill, Euphausia superba. The results show relatively high levels of cadmium in krill, which is assumed to be the main reason for the high levels of cadmium in petrels and skuas. Cadmium is almost absent in eggs, but accumulates very rapidly with age in nestlings. The copper concentrations in livers of nestling petrels reach very high levels during growth. This may be seen in connection with physiological development processes. Mercury seems to be accumulated with age and between trophic levels. Among the nestlings, the mercury levels decrease with increasing age, which may be accomplished by the excretion of mercury through the growth of feathers and as a dilution effect during growth. Selenium and mercury are inversely correlated in nestlings. The levels of zinc were similar for different nestling stages and between nestlings and adults in skuas and petrels.  相似文献   

Rehabilitation of industrial areas: case histories from England and Germany   总被引：4，自引：0，他引：4  

F. G. Bell  D. D. Genske  A. W. Bell 《Environmental Geology》2000,40(1-2):121-134

 Contaminated and possibly hazardous ground represents a problem in all of the industrialized countries of the world. The investigation of a site that is suspected of being contaminated differs somewhat from a routine site investigation. Sampling of soils, groundwater and gas-producing material may be required. Various precautions may be necessary in doing this and operatives may have to wear protective clothing. Four case histories have been chosen to illustrate different aspects of the rehabilitation of abandoned contaminated land, namely, investigation, assessment, ground treatment and redevelopment. The first comes from Leeds in West Yorkshire, England, and outlines how a site investigation was undertaken and the nature of the contamination present, together with a note on the suggested redevelopment. The remaining three case histories are taken from the heavily industrialized district of the Ruhr in Germany, where extensive mining of coal and associated industries were developed from the mid-19th century onwards. The first considers the site of the former Graf Moltke mine near Essen. In this instance, the somewhat novel methods of data assessment and ground treatment are dealt with. The Mont Cenis site at Herne-Sodingen is one of the more notable old mining/industrial sites undergoing redevelopment in the state of North Rhine Westphalia. Hence, the case history concentrates of this aspect of rehabilitation. This involves not only the construction of new and interesting structures but an attempt to reduce energy consumption in an attempt to effect the concept of sustainable development of an urban area. The last example deals with the abandoned site of the Minister Achenbach mine at Lünen, where the ground conditions were further complicated by the presence of old bomb craters that had been filled with a variety of materials. In addition, because of the suspected presence of former foundation structures in the ground an electromagnetic survey was carried out across part of the site, the areas of high conductivity suggesting their presence. Received: 15 September 1999 · Accepted: 14 March 2000  相似文献   

Comparative ecophysiology of active zoobenthic filter feeding, essence of current knowledge     

H. U. Riisgrd  P. S. Larsen 《Journal of Sea Research》2000,44(3-4)

The present contribution gives an overview of current knowledge of a comprehensive and steadily growing research field. The first section deals with water pumping and particle retention mechanisms in ciliary and muscular filter feeders. The second section examines the biological filter pumps in order to assess adaptation to the environment. Filter-feeding benthic invertebrates have evolved filter pumps to solve common basic problems. This has led to a large degree of similarity between otherwise distant standing species, which makes comparative studies interesting and important. The present review of zoobenthic filter feeding aims at accentuating such recognition.  相似文献   

Non-linear amplification of a magnetic field driven by cosmic ray streaming     

S. G. Lucek  A. R. Bell 《Monthly notices of the Royal Astronomical Society》2000,314(1):65-74

One-, two- and three-dimensional numerical results of the non-linear interaction between cosmic rays and a magnetic field are presented. These show that cosmic ray streaming drives large-amplitude Alfvénic waves. The cosmic ray streaming energy is very efficiently transferred to the perturbed magnetic field of the Alfvén waves, and the non-linear time-scale of the growth of the waves is found to be very rapid, of the order of the gyro-period of the cosmic ray. Thus, a magnetic field of interstellar values, assumed in models of supernova remnant blast wave acceleration, would not be appropriate in the region of the shock. The increased magnetic field reduces the cosmic ray acceleration time and so increases the maximum cosmic ray energy, which may provide a simple and elegant resolution to the highest energy Galactic cosmic ray problem, where the cosmic rays themselves provide the fields necessary for their acceleration.  相似文献   

S-asteroids 387 Aquitania and 980 Anacostia: Possible fragments of the breakup of a spinel-bearing parent body with C03/CV3 affinities     

Thomas H. Burbine  Michael J. Gaffey  Jeffrey F. Bell 《Meteoritics & planetary science》1992,27(4):424-434

Abstract— Asteroids 387 Aquitania and 980 Anacostia are anomalous members of the S-class. Their reflectance spectra exhibit a strong broad absorption feature longwards of 1.5 μm and no significant feature near 1 μm. Their spectra indicate the presence of spinel, an aluminum-magnesium oxide mineral commonly present in inclusions in CV3 and CO3 meteorites. Spinel probably makes up only a small percentage of the surface assemblages of these asteroids, but its spectral effect may be enhanced by its presence in fine-grained white inclusions in immature asteroid regoliths. It is speculated that Aquitania and Anacostia represent material formed in the same nebular zone as the CV3 and CO3 chondrites but either: A) at an earlier time in the nebula when such inclusions might have been a relatively larger fraction of the nebular grain population, or B) in local regions where nebular processes (e.g., settling to the midplane) had concentrated such inclusions. The close similarity of two orbital elements (a, i) suggests that Aquitania and Anacostia may be members of a partially dispersed asteroid family produced by the early disruption of a spinel-bearing parent body.  相似文献   

Interplanetary diffusive shock acceleration: Exponential or power-law spectra?     

M. Savopulos  J. J. Quenby  A. R. Bell 《Solar physics》1995,157(1-2):349-366

A new method for solving the transport equation and boundary condition describing diffusive shock acceleration for interplanetary corotating interaction regions is provided. It involves inverting a quindiagonal matrix. Application of this method to realistic parameters indicates that the parallel diffusion coefficient magnitude is critical in determining whether observed particle distribution functions are exponential or power law.  相似文献   

Some problems associated with past mining at a mine in the Witbank coalfield, South Africa   总被引：2，自引：0，他引：2  

S. E. T. Bullock  F. G. Bell 《Environmental Geology》1997,33(1):61-71

 Mining in the Witbank Coalfield commenced at the turn of the century. Initially there was little environmental degradation associated with mining activities; however, in the late 1930s and early 1940s a pillar-robbing programme commenced. At one particular mine this has had marked effects on the environment. Primary effects include subsidence, the appearance of tension cracks at the surface and crownhole development. Secondary effects include spontaneous combustion of the coal worked, as air has been provided with ready access to the mine, accelerated subsidence due to the strength of many pillars being reduced by burning, and a marked deterioration in groundwater quality in the area. Spoil heaps also form blemishes on the landscape. These contain significant amounts of coal and have undergone spontaneous combustion. The deterioration in the water quality has led to the decimation of vegetation in some areas and the eradication of aquatic flora and fauna in a nearby stream. Received: 5 March 1997 · Accepted: 1 July 1997  相似文献   

Late Triassic fluvial and marine shelf succession, Quebrada Doña Inés Chica, Atacama region, northern Chile     

C.M. Bell  M. Suarez   《Journal of South American Earth Sciences》1991,4(4)

A 400-meter-thick volcanic and fine-grained clastic sedimentary succession in Quebrada Doña Ines Chica (26°07′S latitude; 69°20'W longitude) provides a record of Late Triassic deposition in the Atacama region of northern Chile. The strata are conformably overlain by fossiliferous marine limestones and sandstones of Late Triassic to Early Jurassic (Sinemurian) age which contain the oldest ichthyosaur remains known from Central and South America. The clastic succession is interpreted as coastal fluvial deposits, with the overlying limestones representing shelf deposits.  相似文献   

Fault‐controlled fluid flow inferred from hydrothermal vents imaged in 3D seismic reflection data,offshore NW Australia          下载免费PDF全文

Craig Magee  Oliver B. Duffy  Kirsty Purnell  Rebecca E. Bell  Christopher A.‐L. Jackson  Matthew T. Reeve 《Basin Research》2016,28(3):299-318

Fluid migration pathways in the subsurface are heavily influenced by pre‐existing faults. Although studies of active fluid‐escape structures can provide insights into the relationships between faults and fluid flow, they cannot fully constrain the geometry of and controls on the contemporaneous subsurface fluid flow pathways. We use 3D seismic reflection data from offshore NW Australia to map 121 ancient hydrothermal vents, likely related to magmatic activity, and a normal fault array considered to form fluid pathways. The buried vents consist of craters up to 264 m deep, which host a mound of disaggregated sedimentary material up to 518 m thick. There is a correlation between vent alignment and underlying fault traces. Seismic‐stratigraphic observations and fault kinematic analyses reveal that the vents were emplaced on an intra‐Tithonian seabed in response to the explosive release of fluids hosted within the fault array. We speculate that during the Late Jurassic the convex‐upwards morphology of the upper tip‐lines of individual faults acted to channelize ascending fluids and control where fluid expulsion and vent formation occurred. This contribution highlights the usefulness of 3D seismic reflection data to constraining normal fault‐controlled subsurface fluid flow.  相似文献