Spatial assessment of fishing effort around European marine reserves: implications for successful fisheries management   总被引：7，自引：0，他引：7  

Stelzenmüller V  Maynou F  Bernard G  Cadiou G  Camilleri M  Crec'hriou R  Criquet G  Dimech M  Esparza O  Higgins R  Lenfant P  Pérez-Ruzafa A 《Marine pollution bulletin》2008,56(12):2018-2026

We examined the spatial dynamic of artisanal fishing fleets around five European marine protected areas (MPAs) to derive general implications for the evaluation of MPAs as fisheries management tools. The coastal MPAs studied were located off France, Malta and Spain and presented a variety of spatial designs and processes of establishment. We developed a standardized methodology to define factors influencing effort allocation and to produce fishing effort maps by merging GIS with geostatistical modelling techniques. Results revealed that in most cases the factors “distance to the no-take”, “water depth”, and “distance to the port” had a significant influence on effort allocation by the fishing fleets. Overall, we found local concentration of fishing effort around the MPA borders. Thus, neglecting the pattern of fishing effort distribution in evaluating MPA benefits, such as spillover of biomass, could hamper sound interpretation of MPAs as fisheries management tools.  相似文献   

Carbonation and decarbonation of eclogites: the role of garnet   总被引：3，自引：0，他引：3  

Ruth Knoche  Russel J. Sweeney  Robert W. Luth 《Contributions to Mineralogy and Petrology》1999,135(4):332-339

Carbonates are potentially significant hosts for primordial and subducted carbon in the Earth's mantle. In addition, the coexistence of carbonate with silicates and reduced carbon (diamond or graphite), allows constraints to be placed on the oxidation state of the mantle. Carbonate-silicate-vapor reactions control how carbonate + silicate assemblages may form from carbon-bearing vapor + silicate assemblages with increasing pressure. In olivine-bearing rocks such as peridotite, considered the dominant rock type in the upper mantle, the lowest-pressure carbonate-forming reactions involve olivine (±clinopyroxene) reacting with CO₂ (e.g., Wyllie et al. 1983). In eclogitic rocks, the essential mineral assemblage is omphacitic clinopyroxene + garnet, without olivine. Therefore, alternative carbonate-forming reactions must be sought. The carbonation of clinopyroxene via the reaction dolomite + 2 coesite = diopside + 2 CO₂ was studied experimentally by Luth (1995). The alternative possibility that garnet reacts with CO₂ is explored here by determining the location of the reaction 3 magnesite + kyanite + 2 coesite = pyrope + 3 CO₂ between 5 and 11 GPa in multi-anvil apparatus. At the temperatures ≥1200 °C, carbonation of eclogitic rocks with increasing pressure will proceed initially by reaction with clinopyroxene, because the pyrope-carbonation reaction lies at higher pressures for a given temperature than does the diopside-carbonation reaction. Diluting the pyrope component of garnet and the diopside component of clinopyroxene to levels appropriate for mantle eclogites does not change this conclusion. At lower temperatures, appropriate for “cold” slabs, it is possible that the converse situation will hold, with initial carbonation proceeding via reaction with garnet, but this possibility awaits experimental confirmation. Decarbonation of an eclogite under “normal mantle” geothermal conditions by a decrease in pressure, as in an ascending limb of a mantle convection cell, would be governed by the formation of clinopyroxene + CO₂. At higher pressure than this reaction, any CO₂ produced by the breakdown of magnesite reacting with kyanite and coesite would react with clinopyroxene to produce dolomite + coesite. Release of CO₂ from eclogite into mantle peridotite would form carbonate at sub-solidus conditions and produce a dolomitic carbonate melt if temperatures are above the peridotite-CO₂ solidus. Received: 4 May 1998 / Accepted: 23 December 1998  相似文献   

A palaeomagnetic secular variation record from c. 120 000 yr-old New Zealand cave sediments     

Gillian M. Turner  Ruth G. Lyons 《Geophysical Journal International》1986,87(3):1181-1192

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U-Pb zircon dating of mafic dykes and its application to the Proterozoic geological history of the Vestfold Hills,East Antarctica   总被引：3，自引：0，他引：3  

Ruth Lanyon  Lance P. Black  Hans-Michael Seitz 《Contributions to Mineralogy and Petrology》1993,115(2):184-203

The Vestfold Hills, one of several Archaean cratonic blocks within the East Antarctic Shield, comprises a high-grade metamorphic basement complex intruded by at least nine generations of Early to Middle Proterozoic mafic dykes. Extensive U-Pb ion microprobe (SHRIMP) analyses of zircons, derived predominantly from late-stage felsic differentiates of the mafic dykes, provide precise crystallisation ages for several dyke generations. These new ages enable constraints to be placed on both the history of mafic magmatism in the Vestfold Hills and the timing of the various interspersed Proterozoic deformation events. In addition to demonstrating the utility of zircons derived from felsic late-stage differentiates for the dating of co-genetic mafic dykes, this study also places doubt on previous wholerock Rb-Sr dating of mafic dyke suites in this and other areas of East Antarctica. The ²⁰⁷Pb/²⁰⁶Pb zircon ages of 2241±4 Ma and 2238±7 Ma for the Homogeneous and Mottled Norites, respectively, provide a younger emplacement age for associated group 2 High-Mg tholeiite dykes than the whole-rock Rb-Sr date (2424±72 Ma) originally interpreted as the age of all high-Mg intrusives in the Vestfold Hills. Zircon ages of 1754±16 Ma and 1832±72 Ma confirm the previously defined Rb-Sr age of the group 2 Fe-rich tholeiites. Two later dyke generations, the group 3 and 4 Fe-rich tholeiites, are distinguished on the basis of field orientations and cross-cutting relationships, and yield zircon emplacement ages of 1380±7 Ma and 1241±5 Ma which also define minimum ages for two suites of lamprophyre dykes. Xenocrystic zircons within both felsic segregations and mafic dykes yield zircon ages of 2478±5 Ma to 2740 Ma, indicating the presence of Archaean crustal source rocks of this antiquity beneath the Vestfold Hills.  相似文献   

Dependence of radio emission in large Hα flares 1967–1970 upon the orientation of the local solar magnetic field     

Edmond C. Roelof  Helen W. Dodson  E. Ruth Hedeman 《Solar physics》1983,85(2):339-349

During 1967–1970, the greatness of 90 large flares (H importance 2) was influenced by the orientation of the large-scale ( 100 000 km) magnetic field structure over the flare site. Although the average X-ray and optical emissions are only slightly larger for flares with their overlying fields directed southward, as opposed to northward, the meter-wave-length prompt flux maxima are, on average, an order of magnitude greater for the flares with southward oriented magnetic fields. There is a comparable, but possibly smaller difference in the 10 cm- fluxes. We therefore conclude that, during this period, the orientation of the overlying magnetic field affects the amount of electromagnetic flare energy radiated promptly in the corona (10 cm- and m-), relative to that radiated in the chromosphere (X-ray and optical). We demonstrate that this statistical effect shows some variability in degree during the period, although the trend is consistent throughout.  相似文献   

A pollution history of Chesapeake Bay     

Edward D. Goldberg  Vern Hodge  Minoru Koide  John Griffin  Eric Gamble  Owen P. Bricker  Gerry Matisoff  George R. Holdren  Ruth Braun 《Geochimica et cosmochimica acta》1978,42(9):1413-1425

Present day anthropogenic fluxes of some heavy metals to central Chesapeake Bay appear to be intermediate to those of the southern California coastal region and those of Narragansett Bay. The natural fluxes, however, are in general higher. On the bases of Pb-210 and Pu-239 + 240 geochronologies and of the time changes in interstitial water compositions, there is a mixing of the upper 30 or so centimeters of the sediments in the mid-Chesapeake Bay area through bioturbation by burrowing mollusks and polychaetes. Coal, coke and charcoal levels reach one percent or more by dry weight in the deposits, primarily as a consequence of coal mining operations.  相似文献   

What information do policy makers need to develop climate adaptation plans for smallholder farmers? The case of Central America and Mexico   总被引：1，自引：1，他引：0  

Camila I. Donatti  Celia A. Harvey  M. Ruth Martinez-Rodriguez  Raffaele Vignola  Carlos Manuel Rodriguez 《Climatic change》2017,141(1):107-121

Scientific and technical information can increase the ability of policy makers to make strategic decisions. However, climate change policy is often formulated without significant input from science. We examine whether the availability and accessibility of information related to climate change is a major barrier for policy action on climate change adaptation for smallholder farmers. We also investigate whether scientific information related to climate change is available and used in policy making in Central America and Mexico. Our online survey of 105 decision makers indicated that a lack of scientific and technical information hinders policy makers from developing policies to help smallholder farmers adapt to climate change. Specific needs include information on the impacts of climate change on water availability for agriculture and the areas that are or will be prone to flooding, droughts or landslides. Information about the location of the farmers who are most vulnerable to climate change, the projected temperature and precipitation in agricultural areas and the expected impacts of climate change on crop yields or animal productivity, is also needed. Despite high interest in having scientific information guide policy making, many respondents indicated that policy makers rarely use this information in adaptation planning. In addition to ensuring that relevant information is available to inform policy making, technical and scientific information must be published in venues that are readily accessible for policy makers, easy to understand, and written in a format that is policy-relevant. It is also critical that scientific articles provide specific recommendations for achieving desired policy outcomes.  相似文献   

Glucose fluxes and concentrations of dissolved combined neutral sugars (polysaccharides) in the Ross Sea and Polar Front Zone, Antarctica     

David L. Kirchman  Benedikt Meon  Hugh W. Ducklow  Craig A. Carlson  Dennis A. Hansell  Grieg F. Steward 《Deep Sea Research Part II: Topical Studies in Oceanography》2001,48(19-20)

We hypothesized that dissolved carbohydrates would be large components of the labile dissolved organic carbon (DOC) pool and would support much bacterial growth in Antarctic waters, especially the Ross Sea, since previous work had observed extensive phytoplankton blooms with potentially high production rates of carbohydrates in Antarctic seas. These hypotheses were tested on cruises in the Ross Sea and Antarctic Polar Front Zone as part of the US JGOFS program. Concentrations and fluxes of free glucose (the only free sugar detected) were very low, but dissolved polysaccharides appeared to be important components of the DOC pool. Concentrations of dissolved combined neutral sugars increased >3-fold during the phytoplankton bloom in the Ross Sea and were a large fraction (ca. 50%) of the semi-labile fraction of DOC. The relatively high concentrations of dissolved combined neutral sugars, which are thought to be quite labile, appear to explain why DOC accumulated during the phytoplankton bloom was degraded so quickly once the bloom ended. Some of the polysaccharides appeared to be more refractory, however, since dissolved combined neutral sugars were observed in deep waters (>550 m) and in early spring (October) in the Ross Sea, apparently having survived degradation for >8 months. The molecular composition of these refractory polysaccharides differed from that of polysaccharides sampled during the phytoplankton bloom. Fluxes of DOC were low in the Ross Sea compared to standing stocks and fluxes of particulate material, but the DOC that did accumulate during the phytoplankton bloom appeared to be sugar-rich and relatively labile.  相似文献   

Die Messung ultravioletter Strahlung mit einem Photoresist als Empfänger     

Dr. Ruth Lotmar  Dr. Ernst Rüst 《Theoretical and Applied Climatology》1966,14(3-4):360-383

Zusammenfassung Es wird ein photochemisches UV-Meßverfahren angegeben, das als Empfänger eine strahlungsempfindliche Härtungsschicht (Photoresist) benutzt. Das Maß der Härtung ist die der eingestrahlten Energie proportionale Schichtdicke, welche interferometrisch bestimmt wird.Das Verfahren ist vor allem als Feldmethode gedacht; Messung und Auswertung lassen sich zeitlich und räumlich trennen. Das Meßzubehör ist leicht, transport-unempfindlich und ohne besondere Kenntnis zu bedienen. Eine zentrale Stelle kann zu beliebigem Zeitpunkt die Messungen zahlreicher Beobachter auswerten.Die praktische Anwendungsmöglichkeit des Resist-Verfahrens wurde in über 300 Feldversuchen im Tiefland und in Höhenlagen geprüft. Unter Verwendung von Filtergläsern, dem Flüssigkeitsfilter nach Bäckström und zweier Interferenzfilter wurden das Gesamt-UV, das UV-A und das UV-B getrennt gemessen.Dem Resist-Verfahren sind wie jeder integrierenden UV-Meßmethode bestimmte Grenzen gesetzt, bedingt durch den nicht linearen Verlauf der spektralen Empfindlichkeitskurve des Empfängers, und durch die nicht senkrecht abfallenden Transmissionskurven der verwendeten Filter. Dieser Umstand ist bei vergleichenden UV-Intensitätsbestimmungen zu berücksichtigen, da er gewisse Fehlerquellen in sich schließt. Trotz dieser Einschränkung, die speziell für das Gesamt-UV und für das UV-B gilt, nicht dagegen für das UV-A, dürfte sich das feldmäßig anwendbare Resist-Verfahren zur Lösung bestimmter medizinisch-bioklimatologischer UV-Strahlungsprobleme als brauchbar erweisen.

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Summary The authors discuss a photo-chemical ultra-violet measuring procedure which uses as receiver a hardening coating (photoresist) sensitive to radiation. The measure of hardening is the thickness of the coating which is proportional to the irradiated energy interferometrically determined.The procedure is mainly intended as a field method; measurement and evaluation can be separated relating to time and place. The measuring accessories are light, insensible to transport and can be worked without special knowledge. A central institute may evaluate the measurements of various observers at any date chosen.The practical application of the resist procedure has been examined in the lowland and in altitudes by more than 300 field measurements. UV total, UV-A und UV-B have been measured separately by means of filter glasses, the Bäckström liquid filter and two interference filters.Limits are set to the resist procedure as to every integrating UV measuring method, caused by the non-linear course of the spectral sensitivity curve of the receiver and by the transmission curves of the filters not vertically falling off. This fact has to be considered for the comparative determinations of UV intensity since it includes certain sources of error. In spite of this restriction which applies especially to UV total and UV-B, but not to UV-A, the resist procedure may prove useful, especially for field measurements, for the solution of certain medical-bioclimatological UV radiation problems.

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Résumé On décrit ici une méthode de mesure photochimique de l'ultraviolet. Cette méthode utilise comme récepteur une couche d'insolubilisation (photorésist) sensible au rayonnement. Le degré d'insolubilisation est donné par l'épaisseur de la couche qui est, elle, proportionnelle à l'énergie du rayonnement reçu. Cette épaisseur est ensuite déterminée par interférométrie.Cette méthode est applicable surtout en campagne. En effet, la mesure et son évaluation peuvent être disjointes aussi bien dans le temps que dans l'espace. L'appareil de mesure est léger, robuste et peut être utilisé par un personnel n'ayant pas de connaissances particuliéres. Un poste centralisateur peut mettre en valeur les mesures faites par plusieurs observateurs et cela à un moment choisi librement.Les possibilités d'utilisation du procédé «résist» ont été mises à l'épreuve au cours de plus de 300 essais et cela aussi bien en plaine qu'en montagne. En utilisant des verres filtrants, un filtre à liquide selon Bäckström et deux filtres à interférence, on a pu mesurer séparément l'ultra-violet complet, l'UV-A et l'UV-B.Comme pour chaque méthode de mesure par intégration de l'ultraviolet, le procédé «résist» n'est utilisable que dans certaines limites. Celles-ci sont conditionnées par l'état non linéaire de la courbe de sensibilité spectrale du récepteur et par le fait que les courbes de transmission des filtres utilisés ne sont pas perpendiculaires. Ces phénomènes doivent être pris en considération lors de la détermination comparative de l'intensité des rayons ultra-violets, car ils impliquent certaines sources d'erreurs. Malgré ces restrictions—valables surtout pour l'ultra-violet total et l'UV-B, mans pas pour l'UV-A, le procédé «résist» devrait s'imposer pour la solution de certains problèmes de rayonnement ultra-violet en bioclimatologie médicale.

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Site characterisation of a basin-scale CO<Subscript>2</Subscript> geological storage system: Gippsland Basin,southeast Australia     

C. M. Gibson-Poole  L. Svendsen  J. Underschultz  M. N. Watson  J. Ennis-King  P. J. van Ruth  E. J. Nelson  R. F. Daniel  Y. Cinar 《Environmental Geology》2008,54(8):1583-1606

Geological storage of CO₂ in the offshore Gippsland Basin, Australia, is being investigated by the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) as a possible method for storing the very large volumes of CO₂ emissions from the nearby Latrobe Valley area. A storage capacity of about 50 million tonnes of CO₂ per annum for a 40-year injection period is required, which will necessitate several individual storage sites to be used both sequentially and simultaneously, but timed such that existing hydrocarbon assets will not be compromised. Detailed characterisation focussed on the Kingfish Field area as the first site to be potentially used, in the anticipation that this oil field will be depleted within the period 2015–2025. The potential injection targets are the interbedded sandstones of the Paleocene-Eocene upper Latrobe Group, regionally sealed by the Lakes Entrance Formation. The research identified several features to the offshore Gippsland Basin that make it particularly favourable for CO₂ storage. These include: a complex stratigraphic architecture that provides baffles which slow vertical migration and increase residual gas trapping and dissolution; non-reactive reservoir units that have high injectivity; a thin, suitably reactive, lower permeability marginal reservoir just below the regional seal providing mineral trapping; several depleted oil fields that provide storage capacity coupled with a transient production-induced flow regime that enhances containment; and long migration pathways beneath a competent regional seal. This study has shown that the Gippsland Basin has sufficient capacity to store very large volumes of CO₂. It may provide a solution to the problem of substantially reducing greenhouse gas emissions from future coal developments in the Latrobe Valley.  相似文献