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1.
Water samples have been collected at the surface and bottom layers at 51 locations throughout Chesapeake Bay. The suspended particulate and dissolved fractions of these samples have been analyzed for Cd, Ce, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sc, Sn, Th, U, and Zn using neutron activation analysis and atomic absorption spectrometry. Special chemical procedures were used to preconcentrate the elements of interest in the dissolved samples and separate them from the salt water matrix. The elemental concentrations observed in the dissolved samples were evaluated by direct comparison to those found in coastal seawater; however, the elemental concentrations in the particulate samples (mass per volume of water) were strongly influenced by the total amount of particulate material suspended in the water at time of collection. A double normalization procedure was used to calculate crustal enrichment factors for each sample, and these enrichment factors provided both a means to observe sample-to-sample variations, and also allowed a crude comparison with the natural levels occurring in the earth's crust. 相似文献
2.
P. F. Kingston 《Marine Biology》1974,28(4):317-323
Two allopatric populations of Cardium edule and two of C. glaucum were sampled over a period of 16 months and their gonad maturity cycles compared by histological methods. The onset of both spermatogenesis and oogenesis in C. edule took place between September and October; in C. glaucum it was slightly later, between October and November. Development of the gonads continued slowly throughout the winter, C. glaucum developing marginally faster than C. edule. Maturation accelerated in April and May, with the gonads of both species becoming fully ripe in late May and early June. Spawning of the two species approximately coincided at all the localities investigated. Spawning in C. edule was better coordinated than in C. glaucum. Transplanting cockles of one species to the typical habitat of the other did not appreciably alter the spawning period. The separation of spawning periods in sympatric associations of the two cockles is discussed. 相似文献
3.
Dynamics in the global protected-area estate since 2004 总被引:1,自引:0,他引:1
Edward Lewis Brian MacSharry Diego Juffe-Bignoli Nyeema Harris Georgina Burrows Naomi Kingston Neil D. Burgess 《Conservation biology》2019,33(3):570-579
Nations of the world have committed to a number of goals and targets to address global environmental challenges. Protected areas have for centuries been a key strategy in conservation and play a major role in addressing current challenges. The most important tool used to track progress on protected-area commitments is the World Database on Protected Areas (WDPA). Periodic assessments of the world's protected-area estate show steady growth over the last 2 decades. However, the current method, which uses the latest version of the WDPA, does not show the true dynamic nature of protected areas over time and does not provide information on sites removed from the WDPA. In reality, this method can only show growth or remain stable. We used GIS tools in an approach to assess protected-area change over time based on 12 temporally distinct versions of the WDPA that quantify area added and removed from the WDPA annually from 2004 to 2016. Both the narrative of continual growth of protected area and the counter-narrative of protected area removal were overly simplistic. The former because growth was almost entirely in the marine realm and the latter because some areas removed were reprotected in later years. On average 2.5 million km2 was added to the WDPA annually and 1.1 million km2 was removed. Reasons for the inclusion and removal of protected areas in the WDPA database were in part due to data-quality issues but also to on-the-ground changes. To meet the 17% protected-area component of Aichi Biodiversity Target 11 by 2020, which stood at 14.7% in 2016, either the rate of protected-area removal must decrease or the rate of protected-area designation and addition to the WDPA must increase. 相似文献
4.
JC Gaillard Emmanuel A. Maceda Elodie Stasiak Iwan Le Berre Maria Victoria O. Espaldon 《Journal of Coastal Conservation》2009,13(2-3):119-129
The present study investigates into the link between people’s vulnerability in the face of coastal hazards and sustainable livelihoods. It focuses on the town of Borongan in the Philippines and draws on questionnaire-based surveys and focus group discussions. This research shows that local fishermen are often compelled to go out fishing despite pending typhoon or storm surge to sustain the daily needs of their family. Its also demonstrates that the capacity of these people to protect themselves from the threat is constrained by poor and fragile livelihoods. In the event of a crisis, the study argues that people resort to a range of adjustments on their daily life which is rooted in the strength and diversity of their livelihoods. To reduce people’s vulnerability and enhance capacities to face coastal hazards, the study fosters Community-Based Disaster Risk Reduction with special emphasis to sustainable livelihoods. 相似文献
5.
Helen M. Boylan Randy D. Cain H.M. “Skip” Kingston 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1318-1325
Abstract U.S. Environmental Protection Agency (EPA) Method 7473 for the analysis of mercury (Hg) by thermal decomposition, amalgamation, and atomic absorption spectroscopy has proved successful for use in Hg assessment at coal-fired power stations. In an analysis time of ~5 min per sample, this instrumental methodology can directly analyze total Hg—with no discrete sample preparation—in the solid matrices associated with a coal-fired power plant, including coal, fly ash, bottom ash, and flue gas desulfurization (FGD) material. This analysis technique was used to investigate Hg capture by coal combustion byproducts (CCBs) in three different coal-fired power plant configurations. Hg capture and associated emissions were estimated by partial mass balance. The station equipped with an FGD system demonstrated 68% capture on FGD material and an emissions estimate of 18% (11 kg/yr) of total Hg input. The power plant equipped with low oxides of nitrogen burners and an electrostatic precipitator (ESP) retained 43% on the fly ash and emitted 57% (51 kg/yr). The station equipped with conventional burners and an ESP retained less than 1% on the fly ash, emitting an estimated 99% (88 kg/yr) of Hg. Estimated Hg emissions demonstrate good agreement with EPA data for the power stations investigated. 相似文献
6.
Björklund Blom L Morrison GM Kingston J Mills GA Greenwood R Pettersson TJ Rauch S 《Journal of environmental monitoring : JEM》2002,4(2):258-262
A passive sampler has been developed and is demonstrated in situ for urban runoff. The passive sampler is compared to conventional composite (time-dependent and flow-weighted) bottle sampling during and between storm events. The sampling was carried out at established stormwater stations; before and after a stormwater detention pond. In situ deployment of the passive sampler provides the metal concentrations, corresponding to the electrochemically available fraction of total metal, for time-dependent samples collected in parallel. The sampler provides improved accuracy compared to bottle sampling because contamination during sample transport and handling is minimised. Laboratory handling is reduced by direct analysis of the accumulated metals on the receiving membrane by laser ablation inductively coupled plasma mass spectrometry. Passive sampling also solves the problem of metal speciation change during transport to the laboratory, which is a potential problem for bottle samples. The low cost and convenience of the passive sampler and subsequent analysis should allow significantly more extensive spatial and temporal monitoring of metals in the aquatic environment than has previously been possible. 相似文献
7.
Dr Helen M. Kingston Consultant Clinical Geneticist Umberto Nicolini John Haslam Tony Andrews 《黑龙江环境通报》1993,13(7):637-642
46,XY/47,XY, + 17p + mosaicism was found in two primary amniotic fluid cultures (AFCs). Fetal blood karyotype was normal, but ultrasonography revealed Dandy-Walker malformation and bilateral choroid plexus cysts. Following termination of pregnancy, fetal examination revealed post-axial polydactyly and neuroblastoma-in-situ affecting both adrenals in addition to the cerebellar abnormalities. Mosaicism for the aberrant cell line was confirmed in all fetal tissues sampled and in the placenta. 相似文献
8.
Parth K. Rajyaguru Kimberly V. Pegram Alexandra C. N. Kingston Ronald L. Rutowski 《Die Naturwissenschaften》2013,100(6):507-513
In many animals, males bear bright ornamental color patches that may signal both the direct and indirect benefits that a female might accrue from mating with him. Here we test whether male coloration in the Pipevine Swallowtail butterfly, Battus philenor, predicts two potential direct benefits for females: brief copulation duration and the quantity of materials the male passes to the female during mating. In this species, males have a bright iridescent blue field on the dorsal hindwing surface, while females have little or no dorsal iridescence. Females preferentially mate with males who display a bright and highly chromatic blue field on their dorsal hindwing. In this study, we show that the chroma of the blue field on the male dorsal hindwing and male body size (forewing length) significantly predict the mass of material or spermatophore that a male forms within the female’s copulatory sac during mating. We also found that spermatophore mass correlated negatively with copulation duration, but that color variables did not significantly predict this potential direct benefit. These results suggest that females may enhance the material benefits they receive during mating by mating with males based on the coloration of their dorsal hindwing. 相似文献
9.
R. G. Harcourt J. J. Kingston M. F. Cameron J. R. Waas M. A. Hindell 《Behavioral ecology and sociobiology》2007,61(4):643-652
For polygynous mammals with no paternal care, the number of offspring sired is often the sole measure of male reproductive
success. The potential for polygyny is highest when resources or other environmental factors such as restricted breeding sites
force females to aggregate. In these circumstances, males compete intensely for females and mating success may vary greatly
among males, further intensifying selection for those traits that confer an advantage in reproduction. Hence, determinants
of male success in competition for females are likely to be under strong sexual selection. Paternity analysis was used in
conjunction with measures of age, site fidelity, and behavior during the breeding season to assess variance in male breeding
success in Weddell seals (Leptonychotes weddellii) breeding at Turtle Rock, McMurdo Sound (77.727S, 166.85E) between 1997 and 2000. Paternity could be assigned to 177 pups
at relaxed or 80% confidence level or 111 pups at strict or 95% confidence levels. Weddell seals at Turtle Rock show a modest
degree of polygyny with the greatest number of pups sired by any individual male in a single season equalling 5 or ∼10% of
the pups born. Over four consecutive years, most (89.2%) males sired at least one pup. In a generalized linear model (GLM),
age and the age first seen at the study site as an adult were unrelated to mating success, but adult experience, either site-specific
or elsewhere in McMurdo Sound, over the reproductive life span of males explained nearly 40% of variance in total mating success
with 80% confidence and 24% of variance at 95% confidence. While learning where females are likely to be may enhance male
reproductive success, aquatic mating reduces the ability of males to monopolize females, and thereby increases equity in mating
success. 相似文献
10.
Danz NP Regal RR Niemi GJ Brady VJ Hollenhorst T Johnson LB Host GE Hanowski JM Johnston CA Brown T Kingston J Kelly JR 《Environmental monitoring and assessment》2005,102(1-3):41-65
Understanding the relationship between human disturbance and ecological response is essential to the process of indicator development. For large-scale observational studies, sites should be selected across gradients of anthropogenic stress, but such gradients are often unknown for a population of sites prior to site selection. Stress data available from public sources can be used in a geographic information system (GIS) to partially characterize environmental conditions for large geographic areas without visiting the sites. We divided the U.S. Great Lakes coastal region into 762 units consisting of a shoreline reach and drainage-shed and then summarized over 200 environmental variables in seven categories for the units using a GIS. Redundancy within the categories of environmental variables was reduced using principal components analysis. Environmental strata were generated from cluster analysis using principal component scores as input. To protect against site selection bias, sites were selected in random order from clusters. The site selection process allowed us to exclude sites that were inaccessible and was shown to successfully distribute sites across the range of environmental variation in our GIS data. This design has broad applicability when the goal is to develop ecological indicators using observational data from large-scale surveys. 相似文献