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311.
312.
Human Influences on Water Quality in Great Lakes Coastal Wetlands   总被引:2,自引:0,他引:2  
A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP), total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected, open coastal) and biogeography (two ecoprovinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems.  相似文献   
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314.
Bathymetry, the underwater topography, is a fundamental property of oceans, seas, and lakes. As such it is important for a wide range of applications, like physical oceanography, marine geology, geophysics and biology or the administration of marine resources. The exact requirements users may have regarding bathymetric data are, however, unclear. Here, the results of a questionnaire survey and a literature review are presented, concerning the use of Baltic Sea bathymetric data in research and for societal needs. It is demonstrated that there is a great need for detailed bathymetric data. Despite the abundance of high-quality bathymetric data that are produced for safety of navigation purposes, the digital bathymetric models publicly available to date cannot satisfy this need. Our study shows that DBMs based on data collected for safety of navigation could substantially improve the base data for administrative decision making as well as the possibilities for marine research in the Baltic Sea.  相似文献   
315.
Santhi VA  Hairin T  Mustafa AM 《Chemosphere》2012,86(10):1066-1071
A study to assess the level of organochlorine pesticides (OCPs) and bisphenol A (BPA) in edible marine biota collected from coastal waters of Malaysia was conducted using GC-MS and SPE extraction. An analytical method was developed and validated to measure the level of 15 OCPs and BPA simultaneously from five selected marine species. It was observed that some samples had low levels of p,p′-DDE, p,p′-DDT and p,p′- DDD ranging from 0.50 ng g−1 to 22.49 ng g−1 dry weight (d.w) but significantly elevated level of endosulfan I was detected in a stingray sample at 2880 ng g−1 d.w. BPA was detected in 31 out of 57 samples with concentration ranging from below quantification level (LOQ: 3 ng g−1) to 729 ng g−1 d.w. The presence of OCPs is most likely from past use although there is also indication of illegal use in recent times. The study also reveals that BPA is more widely distributed in coastal species caught off the coast of the most developed state. The potential health risk from dietary intakes of OCPs and BPA from the analysed fish species was negligible.  相似文献   
316.
The Persian Gulf is a semi-enclosed marine system surrounded by eight countries, many of which are experiencing substantial development. It is also a major center for the oil industry. The increasing array of anthropogenic disturbances may have substantial negative impacts on marine ecosystems, but this has received little attention until recently. We review the available literature on the Gulfs marine environment and detail our recent experience in the United Arab Emirates (U.A.E.) to evaluate the role of anthropogenic disturbance in this marine ecosystem. Extensive coastal development may now be the single most important anthropogenic stressor. We offer suggestions for how to build awareness of environmental risks of current practices, enhance regional capacity for coastal management, and build cooperative management of this important, shared marine system. An excellent opportunity exists for one or more of the bordering countries to initiate a bold and effective, long-term, international collaboration in environmental management for the Gulf.  相似文献   
317.
A methodology has been developed to carry out an integrated oil spill vulnerability index, V, for coastal environments. This index takes into account the main physical, biological and socio-economical characteristics by means of three intermediate indexes. Three different integration methods (worst-case, average and survey-based) along with ESI-based vulnerability scores, VESI, proposed for the Cantabrian coast during the Prestige oil spill, have been analyzed and compared in terms of agreement between the classifications obtained with each one for this coastal area. Results of this study indicate that the use of the worst-case index, VR, leads to a conservative ranking, with a very poor discrimination which is not helpful in coastal oil spill risk management. Due to the homogeneity of this coastal stretch, the rest of the methods, VI, VM and VESI, provide similar classifications. However, VM and VI give more flexibility allowing three indexes for each coastal segment and including socio-economic aspects. Finally, the VI procedure is proposed here as the more advisable as using this index promotes the public participation that is a key element in the implementation of Integrated Coastal Zone Management (IZCM).  相似文献   
318.
Demarcation of Coastal High Hazard Areas (CHHAs) in Florida dates back to the passage of the landmark Growth Management Act (GMA) of 1985. There have been two subsequent legislative changes in 1994 and 2006. This paper draws on theories of policy implementation, policy framing and policy learning to shed light on this ‘natural experiment’ and to offer clues about factors that impact how and why policies evolve and devolve even after multiple revisions. Although the case study is focused on Florida, the lessons are transferable to land use and environmental policy makers seeking a balance between economic development, property rights and environmental risk.  相似文献   
319.
The Assessment of Estuarine Trophic Status (ASSETS) screening model has been extended to allow its application to both estuarine and coastal systems. The model, which combines elements of pressure, state and response, was tested on four systems: Maryland Coastal Bays and Long Island Sound in the United States and The Firth of Clyde (Scotland) and Tagus Estuary (Portugal) in the European Union. The overall scores were: Maryland Coastal Bays: Bad; Firth of Clyde: Poor; Tagus Estuary: Good. Long Island Sound was modelled along a timeline, using 1991 data (score: Bad) and 2002 data (score: Moderate). The improvement registered for Long Island Sound is a consequence of the reduction in nutrient loading, and the ASSETS score changed accordingly. The two main areas where developments are needed are (a) In the definition of type-specific ranges for eutrophication parameters, due to the recognition that natural or pristine conditions may vary widely, and the use of a uniform set of thresholds artificially penalizes some systems and potentially leads to misclassification; (b) In the definition and quantification of measures which will result in an improved state through a change in pressures, as well as in the definition of appropriate metrics through which response may be assessed. One possibility is the use of detailed research models where different response scenarios potentially produce changes in pressure and state. These outputs may be used to drive screening models and analyze the suitability of candidate metrics for evaluating management options.  相似文献   
320.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10, 13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period, and then forecast commodity price for the same harvest intervals. Integration of those parameters in our model led us to conclude that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns for coastal plantations does not necessarily require a sacrifice of ecological benefits. Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given.  相似文献   
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