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Throughout the wider Caribbean, marine protected areas (MPAs) are rapidly gaining momentum as a conservation tool, but management performance of existing MPAs is considered low. To enhance MPA management performance, stakeholders are increasingly being invited to discuss, debate, and develop rules about how people should interact with marine ecosystems. Using social and ecological data from a rapid assessment of 31 MPAs and their associated communities in the wider Caribbean, this study investigates stakeholder participation in MPA planning and management, and how participants' views of process quality relate to MPA performance. Findings indicate that (1) participants tended to be male, resource users, participate in community organizations, and have lived fewer years in the community associated with an MPA than non-participants; (2) simply participating was not associated with perceptions of the social and ecological performance of MPAs, however, perceptions of process quality were positively related to views of performance; and (3) resource users' perceptions of an MPA's ecological performance were likely shaped by a variety of factors. Conservation practitioners should be aware that participatory MPA processes are complex and require careful planning if they are to contribute positively to marine conservation efforts. 相似文献
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Michael G. Dalton 《Journal of Environmental Economics and Management》1997,33(3):221-239
This article analyzes the welfare effects of climatic variability from global warming in a stochastic economic growth model and shows that these may be significant. An empirical analysis indicates that the effects of climate change with variability are greater than the corresponding effects without it. Effects with variability are also shown to be more sensitive to variations in the rate of climate change. 相似文献
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Influence of soil type and extraction conditions on perchlorate analysis by ion chromatography 总被引:1,自引:0,他引:1
Perchlorate is a stable anion that has been introduced into the environment through activities related to its production and use as a solid rocket propellant. Perchlorate is thought to transport through soils without being adsorbed; thus, for determination of perchlorate in soil, samples are typically extracted with water prior to analysis. The completeness of extraction depends on perchlorate existing as a free ion within the soil matrix. In this study, perchlorate extraction efficiency was evaluated with five soil types under two different oxygen states. For each soil, 30% (w/w) slurries were prepared and equilibrated under either oxic or anoxic conditions prior to spiking with a stock solution of sodium perchlorate, and the slurries were then maintained for 1-week or 1-month. At the end of the exposure, slurries were centrifuged and separated into aqueous and soil phases. After phase separation, the soil was washed first with deionized water and then with 50mM NaOH, producing second and third aqueous phases, respectively. Perchlorate concentrations in the three aqueous phases were determined using ion chromatography. The results obtained from this study suggest that matrix interference and signal suppression due to high conductivity have greater effects upon observed perchlorate concentrations by ion chromatography than does perchlorate interaction with soil. Thus, a single water extraction is sufficient for quantitative determination of perchlorate in soil. 相似文献
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D. R. Crapper McLachlarf C. D. McLachlan B. Krishnan S. S. Krishnan A. J. Dalton J. C. Steele 《Environmental geochemistry and health》1989,11(2):45-53
Low calcium and high aluminium concentrations in the soils, waters and native foods have been hypothesised as environmental factors contributing to the unusually high incidence of amyotrophic lateral sclerosis and parkinsonism with dementia (ALS-PD) found on the island of Guam. The amounts of elemental aluminium and calcium were measured in foods of the native diet of the Chamorro people of Guam. The amount of aluminium eluted from topsoil by water at pH 7 at 22 °C was also measured. For comparison, food, water and soil samples were collected from two islands which have not reported a high incidence of ALS-PD syndromes: Palau and Jamaica.Compared with agricultural soils of Jamaica or Palau, the agricultural soils of Guam averaged 42-fold higher yield of elutable aluminium. The food data, however, do not indicate a differentially high exposure to elemental aluminium or low calcium intake in the diet of any one population. While this study did not detect an unusually high dietary aluminium or low dietary calcium content, the soils and possibly the dusts of Guam may be a major source of aluminium entering the body of the native people, particularly through the respiratory epithelium. Since iipid soluble organic ligands of aluminium more readily penetrate epithelial membranes, further study of soil aluminium ligands is required. 相似文献
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Ximenes Carolina Falcão Rodrigues Samya Mere Lima Podratz Priscila Lang Merlo Eduardo de Araújo Julia Fernandez Puñal Rodrigues Lívia Carla Melo Coitinho Juliana Barbosa Vassallo Dalton Valentim Graceli Jones Bernardes Stefanon Ivanita 《Environmental science and pollution research international》2017,24(31):24509-24520
Environmental Science and Pollution Research - Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine... 相似文献
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A. L. Vereshchaka G. M. Vinogradov A. Yu. Lein S. Dalton F. Dehairs 《Marine Biology》2000,136(1):11-17
The carbon and nitrogen isotopic composition of 18 faunistic groups collected during the 39th cruise of the R.V. “Akademik
Mstislav Keldysh” in September 1996 at the Broken Spur vent field, MAR, was studied. The trophic structure of the Broken Spur
vent community is considered. All age stages of the shrimp Rimicaris exoculata living 5 m below the main aggregations at black smokers show higher δ15N and more depleted δ13C values than the same stages inhabiting the black smokers themselves. The shrimps R. exoculata and Chorocaris chacei demonstrate ontogenetic changes in δ13C (the former also in δ15N), with smaller individuals showing higher δ15N and more depleted δ13C values than larger shrimps. Benthopelagic and benthic components of the vent community differ significantly in δ13C and δ15N, the benthic fauna being less dependent upon chemosynthetic production.
Received: 30 March 1999 / Accepted: 28 September 1999 相似文献
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Dalton JS Janes PA Jones NG Nicholson JA Hallam KR Allen GC 《Environmental pollution (Barking, Essex : 1987)》2002,120(2):415-422
The bandgap of solid-state TiO2 (3.2 eV) enables it to be a useful photocatalyst in the ultraviolet (lambda < 380 nm) region of the spectrum. A clean TiO2 surface in the presence of sunlight therefore enables the removal of harmful NOx gases from the atmosphere by oxidation to nitrates. These properties, in addition to the whiteness, relative cheapness and non-toxicity, make TiO2 ideal for the many de-NOX catalysts that are currently being commercially exploited both in the UK and Japan for concrete paving materials in inner cities. There is need, however, for further academic understanding of the surface reactions involved. Hence, we have used surface specific techniques, including X-ray photoelectron spectroscopy and Raman spectroscopy, to investigate the NOx adsorbate reaction at the TiO2 substrate surface. 相似文献
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