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71.
Melissa M. Foley Benjamin S. Halpern Fiorenza Micheli Matthew H. Armsby Margaret R. Caldwell Caitlin M. Crain Erin Prahler Nicole Rohr Deborah Sivas Michael W. Beck Mark H. Carr Larry B. Crowder J. Emmett Duffy Sally D. Hacker Karen L. McLeod Stephen R. Palumbi Charles H. Peterson Helen M. Regan Mary H. Ruckelshaus Paul A. Sandifer Robert S. Steneck 《Marine Policy》2010
The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits. 相似文献
72.
Spatial and temporal variation in subtidal molluscan diversity amongst temperate estuarine habitats 下载免费PDF全文
Effective management of marine ecosystems is enhanced when detailed information on biodiversity is available. Key information to underpin management actions and conservation planning includes relationships between species assemblages and environmental gradients, and information on species distributions. We conducted a subtidal biodiversity assessment of surface‐dwelling subtidal molluscs in eight a priori defined habitat types using underwater visual censuses to quantitatively explore relationships between molluscan assemblages, and their correlation with benthic habitats and abiotic variables. In addition, variations in diversity were examined for two key habitat types (areas dominated by Dendronephthya australis and by filter feeders) over a period of 15 months to examine temporal change. We found that molluscs form distinct assemblages within subtidal habitats, but that assemblages within key habitats show inherent temporal variability. Regional (gamma) diversity of molluscs was found to result from a combination of: (i) within habitat alpha diversity, which increased with habitat complexity; (ii) between habitat beta diversity, with significant differences in molluscan assemblages amongst habitats with differing benthic growth, substrate type, and depth; and (iii) temporal beta diversity, with significant changes detected in molluscan assemblages over time. The results demonstrate how habitats and abiotic variables (principally depth and substrate type) combine to contribute to molluscan biodiversity in temperate estuaries, and illustrate the value of these factors as surrogates for surface‐dwelling subtidal molluscs in conservation planning. 相似文献
73.
England is about to embark on the introduction of an integrated approach to the management of its marine environment, known as marine planning. The management of human activity in the marine environment is a central function of marine planning; therefore, stakeholder involvement will be crucial for the successful development and subsequent implementation of marine plans. The range of stakeholder activities, their connection to the marine environment and interest in its management are likely to vary considerably on a local, regional and national scale. It is realistic to assume that it will not be possible to involve every stakeholder all the time; therefore in order to develop efficient and effective stakeholder involvement during the marine planning process it is sensible to determine who to involve, when to involve them, and how to involve them from the outset. This paper discusses the role of stakeholders in the marine planning process through consideration of the results of a stakeholder analysis, which was informed by primary data collated from stakeholders within the Solent. The paper concludes with a proposed mechanism, comprising different organisational units, for managing stakeholder involvement in the marine planning process. 相似文献
74.
Ruarri J. Day-Stirrat Kitty L. Milliken Shirley P. Dutton Robert G. Loucks Stephen Hillier Andrew C. Aplin Anja M. Schleicher 《Marine and Petroleum Geology》2010
Wilcox Group mudstones have been mechanically and geochemically transformed over a temperature range of 20–200 °C. Our research controlled for provenance and age by sampling from five wells, parallel to the paleodepositional axis, all within the Houston delta system. Across the sampled depths, mudstone porosity has been reduced from ∼25 to <10% and bulk mineralogical change as documented by quantitative X-ray diffraction includes decreases in quartz, K-feldspar and kaolinite content whereas illite + illite − smectite, chlorite, and plagioclase increase. These mineral transformations transfer elements at a scale of less than 1 mm from one mineralogical form to another, however, X-ray fluorescence data suggest that among major elements only Al2O3 and TiO2 are fully conserved within the system (trace-element ZrO2 is also conserved). K2O has been added to and SiO2 released from the Wilcox Group mudstones. Cathodoluminescence and secondary electron imaging did not find this SiO2 locally precipitated. We, therefore, document an open-system geochemical behavior. 相似文献
75.
76.
Samples of lake water and coastal seawater from Nova Scotia, Canada, were irradiated with natural or artificial sunlight to investigate the potential for photochemical hydrogen production. Hydrogen photo-production was observed in all natural water samples. Rates of hydrogen formation were highest in coloured lake water (range: 98–163 pmol L− 1h− 1) and lower in seawater (range: 19–45 pmol L− 1 h − 1). Dilutions of the most highly coloured lake sample (Kejimkujik Lake) showed a positive linear relationship between H2 production rates and CDOM concentration. Photo-production rates normalised to UV absorption coefficients at 350 nm indicated that the photochemical efficiency of hydrogen formation varied between samples, perhaps due to differences in the CDOM composition. Photochemical hydrogen formation was also seen in solutions of syringic acid and acetaldehyde: two low-molecular-weight carbonyl compounds found in natural waters. Photochemistry may therefore offer least a partial explanation for the persistently high levels of hydrogen observed in the low-latitude surface ocean. 相似文献
77.
On October 3 and 4, 1986, DSRVAlvin dives encountered a strong current at 2,300 m in South Wilmington Canyon. The current, estimated at 1 knot, transported surficial
sediment and constructed and modified bedforms. It appears to have been constant in its direction of flow from 30 to 40°.
The observed current was probably a burst of fast flow in a region of slow average currents in the Deep Western Boundary Undercurrent.
Such episodic events may have a greater influence on the stratigraphic record than the temporally longer more tranquil flow
conditions. 相似文献
78.
Here we report the results of the first molecular enzymological study of fish UDP-glucuronosyltransferase (UDPGT). UDPGT activities of plaice liver microsomes were greatest for planar phenols and there was low but measurable conjugation of bilirubin, testosterone and androsterone. A highly purified preparation was isolated which possessed activities towards 1-naphthol, bilirubin and testosterone, containing several molecular weight species of Mr 52–56 kDa. On immunoblot analysis these proteins cross-reacted with a polyspecific anti-rat UDPGT antibody, suggesting that a number of plaice UDPGT isoforms with epitopes in common with the corresponding rat enzymes had been purified. 相似文献
79.
cDNA clones for glutathione S-transferases A (GST-A) and A1 (GST-A1) from plaice (Pleuronectes platessa) were expressed as N-terminally 6XHis tagged proteins in Escherichia coli and purified to homogeneity from Ni-NTA silica. GST-A was an efficient catalyst for conjugation of unsaturated alkenals derived from peroxidation of polyunsaturated fatty acids with the highest activity observed with trans-non-2-enal (8 micromol min(-1) mg(-1)). GST-A1 was a very efficient Se-independent glutathione peroxidase with an activity towards cumene hydroperoxide of 25 micromol min(-1) mg(-1). Although the enzymes exhibited moderately high activities towards the model substrate 1-chloro-2,4-dinitrobenzene (CDNB) they exhibited little or no activity towards other common prototypical xenobiotic substrates. Together with data for ontogeny, tissue distribution and inducibility of these enzymes, we contend that a primary function of these enzymes is protection from the harmful effects of lipid peroxidation products generated naturally or exacerbated by xenobiotic exposure. 相似文献
80.