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71.
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73.
Xavier López-Medellín Alicia CastilloExequiel Ezcurra 《Ocean & Coastal Management》2011,54(4):318-329
Mangroves in Northwestern Mexico are vital to maintain coastal environments healthy, to provide nutrients for several food chains, and to supply valuable goods and services that sustain and improve human livelihoods. Many of these values offer a range of opportunities for economic development that attract workers, investors and developers. Recently, federal privatization policies have promoted an accelerated coastal development of this region to obtain large profits in short times, creating competing and overlapping interests to use coastal environments and control key resources. Such intense developments are modifying the ecological conditions of many coastal areas, threatening the provision of important ecosystem services to society. After years of centralized decisions, new paradigms are needed to achieve a coastal management that ensures long-term ecosystem maintenance, fair resource use and social equity. Recognizing the multiplicity of actors involved in coastal management and using a qualitative research methodology, we identified and explored the perspectives of different key stakeholders in the states of Baja California Sur and Sonora, Mexico, to better understand their views on mangroves use and management as well as the interaction among them. We discuss similarities and/or discrepancies found among stakeholders’ perceptions by describing their central ideas and identifying overlapping interests that may create conflicts when defining development and conservation programs or formulating policies. This information also intends to encourage further research on the social-ecological system of the coasts in Northwestern Mexico and to contribute to address coastal management issues in integrated ways that consider the social dimension through documenting stakeholders’ narratives in the future. 相似文献
74.
Marton G. Hidas Roger Proctor Natalia Atkins Julian Atkinson Laurent Besnard Peter Blain Philip Bohm Jon Burgess Kim Finney Dan Fruehauf Guillaume Galibert Xavier Hoenner Jacqui Hope Craig Jones Sebastien Mancini Benedicte Pasquer David Nahodil Kate Reid Katherine Tattersall 《Earth Science Informatics》2016,9(4):525-534
Australia’s Integrated Marine Observing System (IMOS, imos.org.au) is research infrastructure to establish an enduring observing program for Australian oceanic waters and shelf seas. The observations cover physical, biological, and chemical variables to address themes of multi-decadal ocean change, climate variability and weather extremes, boundary currents and inter-basin flows, continental shelf processes and ecosystem responses.IMOS observations are collected by national facilities based on various platform types and operated by partner institutions around the country. In this paper we describe the infrastructure and workflows developed to manage and distribute the data to the public. We highlight the existing standards and open-source software we have adopted, and the contributions we have made. To demonstrate the value of this infrastructure we provide some illustrations of use and uptake.All IMOS data are freely and openly available to the public via the Ocean Portal (https://imos.aodn.org.au). All IMOS-developed software is open-source and accessible at https://github.com/aodn. 相似文献
75.
V. Tu Do Xavier de MontaudouinNicolas Lavesque Hugues BlanchetHervé Guyard 《Estuarine, Coastal and Shelf Science》2011
This study provided evidence that Zostera noltii presence affects macrofauna community structure independently from median sediment grain-size and that the notion of ecosystem health is rather subjective: in the present case, we recorded “good health” in terms of seagrass development, “no impact” in terms of macrobenthic biotic indices and “negative effect” for a given key-population. The occurrence and development of a Z. noltii seagrass bed was surveyed at Banc d’Arguin, Arcachon Bay (France), to estimate the modification of the macrozoobenthic community and of the dynamics of a key-population for the local ecosystem, – the cockle Cerastoderma edule. Even though median grain-size of the sediment decreased only at the very end of the survey, i.e. when seagrass totally invaded the area, most of the macrofauna community characteristics (such as abundance and biomass) increased as soon as Z. noltii patches appeared. The structure of the macrofauna community also immediately diverged between sand and seagrass habitats, without however modifying the tested biotic indices (BENTIX, BOPA, AMBI). The health of the cockle population (growth, abundance, recruitment) was impacted by seagrass development. Related parasite communities slowly diverged between habitats, with more parasites in the cockles from seagrass areas. However, the number of parasites per cockle was always insufficient to alter cockle fitness. 相似文献
76.
Elena Roget Iossif Lozovatsky Xavier Sanchez Manuel Figueroa 《Progress in Oceanography》2006,70(2-4):126
Modern approaches to microstructure data processing, including wavelet denoising, are discussed. The wavelet procedure is applied to small-scale shear signals before estimating the dissipation rate ε and to the temperature/density profiles used to calculate Thorpe scales. Microstructure data obtained on the Mediterranean shelf of Catalonia are used to illustrate various approaches to the Thorpe displacement calculations. It is suggested that the Weibull probability function is an appropriate model for the Thorpe scale distribution. Microstructure measurements from the upper layer of the Boadella reservoir (Catalonia, Spain) support this finding.A new analytical approximation for the 1D Panchev–Kesich spectrum is deduced and the results of ε computation are compared with spectral fitting by the widely used Nasmyth spectrum. Applying the Kraichnan spectral model to compute ε from temperature spectra in the convective-viscous sub-range is examined as an alternative to the Batchelor spectrum. Microstructure measurements taken in Lake Banyoles (Catalonia, Spain) and in the North Atlantic were used for spectral calculations.Statistical analysis of eddy Kb and thermal Kθ diffusivities measured on a shallow shelf of the Black Sea shows the importance of process-orientated domain averaging of the diffusivities in obtaining good correspondence between Kb and Kθ in active turbulent regions. In weakly turbulent, stratified interior layers, the averaged Kb and Kθ differ significantly, which may point to the inapplicability of isotropic formulae used for ε and temperature dissipation χθ estimates, as well as to a dependence of the mixing efficiency γ on the Richardson number or in some cases on regions of fossil turbulence. 相似文献
77.
Jean-Pierre Lefebvre Sylvain Ouillon Vu Duy Vinh Robert Arfi Jean-Yves Panché Xavier Mari Chu Van Thuoc Jean-Pascal Torréton 《Geo-Marine Letters》2012,32(2):103-121
In the Bach Dang–Cam Estuary, northern Vietnam, mechanisms governing cohesive sediment aggregation were investigated in situ
in 2008–2009. As part of the Red River delta, this estuary exhibits a marked contrast in hydrological conditions between the
monsoon and dry seasons. The impact on flocculation processes was assessed by means of surveys of water discharge, suspended
particulate matter concentration and floc size distributions (FSDs) conducted during a tidal cycle at three selected sites
along the estuary. A method was developed for calculating the relative volume concentration for the modes of various size
classes from FSDs provided by the LISST 100X (Sequoia Scientific Inc.). It was found that all FSDs comprised four modes identified
as particles/flocculi, fine and coarse microflocs, and macroflocs. Under the influence of the instantaneous turbulent kinetic
energy, their proportions varied but without significant modification of their median diameters. In particular, when the turbulence
level corresponded to a Kolmogorov microscale of less than ∼235 μm, a major breakup of flocs resulted in the formation of
particles/flocculi and fine microflocs. Fluctuations in turbulence level were governed by seasonal variations in freshwater
discharge and by the tidal cycle. During the wet season, strong freshwater input induced a high turbulent energy level that
tended to generate sediment transfer from the coarser size classes (macroflocs, coarse microflocs) to finer ones (particles/flocculi
and fine microflocs), and to promote a transport of sediment seawards. During the dry season, the influence of tides predominated.
The turbulent energy level was then only episodically sufficiently high to generate transfer of sediment between floc size
classes. At low turbulent energy, modifications in the proportions of floc size classes were due to differential settling.
Tidal pumping produced a net upstream transport of sediment. Associated with the settling of sediment trapped in a near-bed
layer at low turbulent energy, this causes the silting up of the waterways leading to the harbour of Haiphong. 相似文献
78.
J.E. Cinner Xavier BasurtoPedro Fidelman John KuangeRachael Lahari Ahmad Mukminin 《Marine Policy》2012,36(1):278-285
There are considerable efforts by governments, non-governmental organizations (NGOs), and academia to integrate marine conservation initiatives and customary practices, such as taboos that limit resource use. However, these efforts are often pursued without a fundamental understanding of customary institutions. This paper examines the operational rules in use and the presence of institutional design principles in long-enduring and dynamic customary fisheries management institutions in Papua New Guinea, Indonesia, and Mexico. Rather than a “blue print” for devising long-enduring institutions, this study relies on the design principles as a starting point to organize an inquiry into the institutional diversity found in customary governance regimes. Three important trends emerged from this comparative analysis: (1) despite it being notoriously difficult to define boundaries around marine resources, almost 3/4 of the cases in this study had clearly defined boundaries and membership; (2) all of the customary institutions were able to make and change rules, indicating a critical degree of flexibility and autonomy that may be necessary for adaptive management; (3) the customary institutions examined generally lacked key interactions with organizations operating at larger scales, suggesting that they may lack the institutional embeddedness required to confront some common pool resources (CPR) challenges from the broader socioeconomic, institutional and political settings in which they are embedded. Future research will be necessary to better understand how specific institutional designs are related to social and ecological outcomes in commons property institutions. 相似文献
79.
Fate characteristics of nitrogen in runoff from a small agricultural watershed on the south of Huaihe River in China 总被引:2,自引:0,他引:2
Zhan-yu Zhang Li-li Kong Lei Zhu Ji-hong Xia Xavier Patricia 《Environmental Earth Sciences》2012,65(3):835-848
Qualitative and quantitative evolution of the Swarna estuary, during the past 38 years (1967–2005), has been analysed by integrating
the results of field surveys, satellite images, hydrodynamic modelling and topographic data in GIS context. Significant changes
in erosion/accretion patterns of the estuarine banks, inlet configuration and adjacent spits, and origin, morphology, orientation
and areal extent of fifteen braided islands have been estimated. Hydrodynamics of the region is studied through modelling,
and probable flow pattern that is responsible for morphological changes is discussed. The simulated flow patterns indicate
that current speeds are of the order of 10–20 cm/s inside the estuary and of the order of 40 cm/s at the mouth. The Right
bank (Rb) of the estuary is subject to net erosion and the Left bank (Lb) is subject to net accretion. On an average, 20–30%
of the area of all braided islands would be flooded, if the water level rises by 0.7 to 1.0 m. Islands of this estuary are
morphologically very dynamic (migrating towards north, northeast and southwest directions) and subject to net accretion, whereas
only one island (i.e., the Padu) has lost its major portion of landmass. A conceptual inverse distance weighted (IDW) interpolation
model has been generated and evaluated possible flooding on the estuarine shoals and braided islands, due to heavy rainfall
and/or sea-level rise. The model reveals that the possibility of flooding will be higher for those islands which are located
close to the Rb than those close to the Lb. 相似文献
80.
The diversity of serphitid wasps (Proctotrupomorpha: Serphitoidea) in Early Cretaceous (Albian) amber from Spain is described. Four new species have been found representing the genera Serphites Brues 1937, Aposerphites Kozlov and Rasnitsyn 1979, and Microserphites Kozlov and Rasnitsyn 1979. From the Peñacerrada I (Moraza) outcrop two species are described as Aposerphites angustus Ortega-Blanco, Delclòs, Peñalver and Engel, new species and Serphites lamiak, new species. A single species was found at the San Just (Teruel) outcrop and is described as S. silban, new species. Another single specimen was found in El Soplao (Cantabria) outcrop, described as Microserphites soplaensis, new species. This last specimen is especially interesting in sharing typical serphitid and mymarommatoid characters, giving additional support to the apparent close relationship of both groups. 相似文献