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91.
Roger H. Green Brian A. McArdle Robert van Woesik 《Environmental monitoring and assessment》2011,178(1-4):455-460
Contemporary coral reefs are forced to survive through and recover from disturbances at a variety of spatial and temporal scales. Understanding disturbances in the context of ecological processes may lead to accurate predictive models of population trajectories. Most coral-reef studies and monitoring programs examine state variables, which include the percentage coverage of major benthic organisms, but few studies examine the key ecological processes that drive the state variables. Here we outline a sampling strategy that captures both state and process variables, at a spatial scale of tens of kilometers. Specifically, we are interested in (1) examining spatial and temporal patterns in coral population size-frequency distributions, (2) determining major population processes, including rates of recruitment and mortality, and (3) examining relationships between processes and state variables. Our effective sampling units are randomly selected 75 × 25 m stations, spaced approximately 250?C500 m apart, representing a 103 m spatial scale. Stations are nested within sites, spaced approximately 2 km apart, representing a 104 m spatial scale. Three randomly selected 16 m2 quadrats placed in each station and marked for relocation are used to assess processes across time, while random belt-transects, re-randomized at each sampling event, are used to sample state variables. Both quadrats and belt-transects are effectively sub-samples from which we will derive estimates of means for each station at each sampling event. This nested sampling strategy allows us to determine critical stages in populations, examine population performance, and compare processes through disturbance events and across regions. 相似文献
92.
Several Torres Strait communities have significant infrastructure and sacred sites located only a few metres above sea level. As a consequence, these areas are vulnerable to erosion due to the projected increase in storm surge intensity caused by climate change. Common sense suggests that Islanders would welcome new scientific research about how climate change might affect them, in order to understand the significance of these impacts and the timeframes involved. However, one leader has taken a seemingly counterintuitive stance, and has refused to let new climate research occur. We explore why this position was taken, and the implications of this decision for ongoing scientific research. In order to carry out this analysis, we provide a contextual background by assessing Islanders' recent experience with scientific researchers, and the response of policy-makers to it. We find that despite a clearly documented problem with “top-down” decision-making, this process remains. In this instance, we find that there is a systemic lack of collaboration with Islanders to allow them to prioritise their concerns, and a lack of adequate resources to allow them to build their resilience to climate impacts. We conclude that only through a genuine collaborative approach to climate adaptation can activities be properly developed, prioritised and undertaken. 相似文献
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Taggart MA Senacha KR Green RE Jhala YV Raghavan B Rahmani AR Cuthbert R Pain DJ Meharg AA 《Environment international》2007,33(6):759-765
Gyps vulture populations across the Indian subcontinent are declining rapidly and evidence indicates that veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac is the major cause. Exposure of vultures to diclofenac is likely to arise from the consumption of livestock carcasses that have been treated shortly before death, however, detailed information regarding the prevalence and residual levels of diclofenac in carcasses available to vultures in India remains unreported. Here, we present data on diclofenac residues in 1848 liver samples taken from carcasses of dead livestock sampled at 67 sites in 12 states within India, between May 2004 and July 2005. Diclofenac residues were detected in carcasses in all states except Orisa, where only one site was sampled. The overall prevalence of detectable diclofenac (>10 microg kg(-1)) across all states was 10.1% and varied significantly among states, with up to 22.3% prevalence determined in Bihar. The geometric mean concentration of diclofenac found in samples in which the drug was detected was 352 microg kg(-1). The prevalence of carcasses containing diclofenac is similar to that previously proposed to be required to have caused the observed Gyps vulture declines in India. On the 11th of May 2006, the Drug Controller General (India) ordered the withdrawal of all licenses granted for the manufacture of diclofenac for veterinary use within India. However, if Gyps vultures are to be protected, potentially substantial existing stocks now need to be quickly and effectively removed from the Indian veterinary market. 相似文献
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地下水铀污染的原位微生物还原与固定:在美国能源部田纳西橡树岭放射物污染现场的试验 总被引:4,自引:0,他引:4
吴唯民 Jack Carley David Watson 顾宝华 Scott Brooks Shelly D. Kelly Kenneth Kemner Joy D. van Nostran 吴力游 许玫英 周集中 罗剑 Erick Cardenas 黃家琪 Matthew W. Fields Terence L. Marsh James M. Tiedje Stefan J. Green Joel E. Kostk Peter K. Kitanidis Philip M. Jardine Craig S. Criddle 《环境科学学报》2011,31(3):449-459
总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇... 相似文献
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Historical trends of trace metals in a sediment core from a contaminated tidal salt marsh in San Francisco Bay 总被引:1,自引:0,他引:1
Sedimentation of metals preserves historical records of contaminant input from local and regional sources, and measurement
of metals in sediment cores can provide information for reconstruction of historical changes in regional water and sediment
quality. Sediment core was collected from Stege Marsh located in central San Francisco Bay (California, USA) to investigate
the historical input of trace metals. Aluminum-normalized enrichment factors indicate that inputs from anthropogenic sources
were predominant over natural input for Ag, Cu, Pb, and Zn. Among these, lead was the most anthropogenically impacted metal
with enrichment factors ranging from 32 to 108. Depth profiles and coefficients of variation show that As, Cd, and Se were
also influenced by anthropogenic input. The levels of these anthropogenically impacted metals decline gradually towards the
surface due to regulation of the use of leaded gasoline, municipal and industrial wastewater discharge control, and closure
of point sources on the upland of Stege Marsh. Although trace metal contamination is expected to be continuously declining,
the rates of decline have slowed down. For lead, it is estimated to take 44, 82, and 153 years to decrease to probable effects
level (112 μg/g), the San Francisco Bay ambient surface sediment level (43.2 μg/g), and the local baseline levels (5 μg/g),
respectively. Some metals in surface sediments (0–6 cm) are still higher than sediment quality guidelines such as the probable
effects level. To further facilitate the recovery of sediment quality, more efficient management plans need to be developed
and implemented to control trace metals from non-point sources such as stormwater runoff. 相似文献