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91.
As climate change has driven dramatic changes in Northern sea ice regimes, marine mammals have gained iconic status around the world reflecting the perils of global warming. There is a tension between policies that have international support like a ban on seal hunting or whaling, and the adoption of adaptive, flexible rules that are likely to work in Northern places. Whereas most wildlife policy focuses on biological information to inform policy strategy, this analysis focuses on the “human dimensions” of Northern marine mammal management. This research examines ways in which human relationships and modes of governance affect conservation success. Standard analyses of risk to animal populations focused on direct sources of take are inadequate to address multi-causal, complex problems such as climate-induced habitat loss or increased industrialization of the Arctic Ocean. Early conservation policy strategies focusing on the moratorium of take have eliminated or reduced such practices as commercialized hunting and high levels of fisheries bycatch, but may be less relevant in an era in which habitats and climate changes are key drivers of population dynamics. This paper argues that effective adaptive policy requires new ways of learning about and governing human interactions with marine mammals. Through an exploration of marine mammal management in three Northern regions (Alaska, Nunavut, and the Finnish Baltic Sea coast), the paper analyzes the extent to which these marine mammal management regimes are practicing adaptive governance, that is, building cross-scale (local to international) understanding while allowing actors at the local scale the flexibility to direct the creation of rules that are ecologically robust and likely to succeed. Lessons are taken from these examples and used to propose selected policy and research recommendations for the marine mammal policy community.  相似文献   
92.
On voyages in the Iceland Basin in 2007 and 2009, we observed low (ca. 0.1 nM) total dissolved iron concentrations [dFe] in surface waters (<150 m), which increased with depth to ca. 0.2–0.9 nM. The surface water [dFe] was low due to low atmospheric Fe inputs combined with biological uptake, with Fe regeneration from microbial degradation of settling biogenic particles supplying dFe at depth. The organic ligand concentrations [LT] in the surface waters ranged between 0.4 and 0.5 nM, with conditional stability constants (log KFeL) between 22.6 and 22.7. Furthermore, [LT] was in excess of [dFe] throughout the water column, and dFe was therefore largely complexed by organic ligands (>99%). The ratio of [LT]/[dFe] was used to analyse trends in Fe speciation. Enhanced and variable [LT]/[dFe] ratios ranging between 1.6 and 5.8 were observed in surface waters; the ratio decreased with depth to a more constant [LT]/[dFe] ratio in deep waters. In the Iceland Basin and Rockall Trough, enhanced [LT]/[dFe] ratios in surface waters resulted from decreases in [dFe], likely reflecting the conditions of Fe limitation of the phytoplankton community in the surface waters of the Iceland Basin and the high productivity in the Rockall Trough.Below the surface mixed layer, the observed increase in [dFe] resulted in a decrease of the [LT]/[dFe] ratios (1.2–2.6) with depth. This indicated that the Fe binding ligand sites became occupied and even almost saturated at enhanced [dFe] in the deeper waters. Furthermore, our results showed a quasi-steady state in deep waters between dissolved organic Fe ligands and dFe, reflecting a balance between Fe removal by scavenging and Fe supply by remineralisation of biogenic particles with stabilisation through ligands.  相似文献   
93.
We present results from the United Kingdom Infrared Telescope observations of the impact of Deep Impact with Comet 9P/Tempel 1, on July 4, 2005 UT. These observations were carried out in conjunction with the worldwide observing campaign co-ordinated by K.J. Meech [Meech, K.J., and 208 colleagues, 2005. Science 310, 265-269]. The UKIRT team was the first to observe and announce the successful impact. At 05:50:52 (±2.5 s) UT the visible camera that is used to guide the telescope on the comet showed the start of a rapid rise in intensity, such that the visible brightness of Tempel 1 approximately doubled in 70 s. After that time there was a steady increase in the visible flux from the comet until it reached a maximum around 35 min post-impact, at which point it was more than ten times its original intensity. From an average of the time to maximum brightness and the time to noticeable intensity decline, we deduce that the material ejected by the impact expanded with a range of velocities between ∼125 and ∼390 m/s. We also observed water emission lines in the spectral region from 2.8945 to 2.8985 μm. We noted several water lines, which are known to be pumped by sunlight. But there was a lower intensity spectral component, which we propose may result from solar heating of icy grains freshly exposed by the impact.  相似文献   
94.
Alaska is among the fastest warming places on Earth, and the Interior region is warming the most statewide. Significant regional-scale ecosystem services disruptions are affecting Alaska Natives’ subsistence hunting and harvest success. The well-being of rural native communities is still highly dependent on access and ability to harvest wild foods such as salmon and moose (Alces alces gigas) among many others. Over the last decade communities in the Koyukuk-Middle Yukon (KMY) region of Interior Alaska report an inability to satisfy their needs for harvesting moose before the hunting season closes, citing warmer falls, changing precipitation and water levels, and the regulatory framework as primary causes. Through the integration of ethnographic methods to record indigenous observations and understanding of climate (IC) with analysis of meteorological data, we provide a comprehensive picture of vulnerability to recent warming trends in the Koyukuk-Middle Yukon region of Interior Alaska, one that captures more than statistical analysis of “norms” can provide. We will demonstrate how low exposure resulting in a small shift in seasonality has truly socially significant effects to people “on the ground” when community sensitivity is high because of the convergence of multiple social-ecological stressors. In this case, a seemingly small climatic exposure when combined with high social-ecological system sensitivity results in vulnerability to this climate change-related seasonality shift because of: (a) the effects on moose and the social-ecological dynamics of the system, and (b) the importance of this time of the year to meeting annual subsistence needs.  相似文献   
95.
Magellanic penguins (Spheniscus magellanicus) are non-breeding winter visitors to the Brazilian coast. In 2008 and 2010, plastic items and other marine debris were found in the stomachs and intestines of 15% of 175 dead penguins collected in the Lagos Region of the state of Rio de Janeiro. One bird had its stomach perforated by a plastic straw, which may have caused its death. There are few records of penguins ingesting plastic litter, but previous studies have found similar levels of debris ingestion among Magellanic penguins stranded on the Brazilian coast (35.8% of 397 birds). The high incidence of marine debris in this species in Brazil may result at least in part from the predominance of juveniles reaching these waters, as juvenile penguins may have a broader diet than adults. It is unclear to what extent plastic ingestion affects the mortality rate in this species and whether the incidence in stranded birds reflects that in the entire population. The present study addresses the increasing impact of plastic debris on marine life.  相似文献   
96.
Geomorphic mapping in the upper Conejos River Valley of the San Juan Mountains has shown that three distinct periods of aggradation have occurred since the end of the last glacial maximum (LGM). The first occurred during the Pleistocene–Holocene transition (~ 12.5–9.5 ka) and is interpreted as paraglacial landscape response to deglaciation after the LGM. Evidence of the second period of aggradation is limited but indicates a small pulse of sedimentation at ~ 5.5 ka. A third, more broadly identifiable period of sedimentation occurred in the late Holocene (~ 2.2–1 ka). The latest two periods of aggradation are concurrent with increases in the frequency of climate change in the region suggesting that Holocene alpine and sub-alpine landscapes respond more to rapid changes in climate than to large singular climatic swings. Soil development and radiocarbon dating indicate that hillslopes were stable during the Holocene even while aggradation was occurring in valley bottoms. Thus, we can conclude that erosion does not occur equally throughout the landscape but is focused upslope of headwater streams, along tributary channels, or on ridge tops. This is in contrast to some models which assume equal erosion in headwater basins.  相似文献   
97.
98.
The Okhimath area in the Uttarakhand state of India witnessed a large-scale occurrence of landslides on 14 September 2012 due to intense rainfall. As per news reports, this event resulted in the death of 51 people and a significant loss of property. In this study, the damage assessment results of the Okhimath landslides derived from the analysis of very high resolution (VHR) images received from Cartosat-2, Resourcesat-2, Kompsat-2 and GeoEye-1 satellites are presented. These datasets were acquired through a coordinated effort of the Indian Space Research Organisation and International Charter Space and Major Disasters. A total of 126 buildings, 34.5 ha of agricultural land and 7.78 km of road were identified as damaged through the VHR satellite data analysis. Using a semi-automatic landslide detection technique, 473 landslides covering a 2.25-km2 area were also identified. Villages such as Mangali, Chunni, Brahman Kholi, Semla, Paldwadi, Saari and Giriyagaon are found to be most affected due to this event. The damage is mainly attributed to rock slides which originated in the escarpment zone which later converted to debris flows by scouring the material along the run-out zone.  相似文献   
99.
The northern mid-latitudes of Uranus produce greater episodes of bright cloud formation than any other region on the planet. Near 30°N, very bright cloud features were observed in 1999, 2004, and 2005, with lifetimes of the order of months. In October 2011, Gemini and HST observations revealed another unusually bright cloud feature near 23°N, which was subsequently identified in July 2011 observations and found to be increasing in brightness. Observations obtained at Keck in November 2011 revealed a second bright spot only 2°N of the first, but with a substantially different drift rate (?9.2°E/day vs ?1.4°E/day), which we later determined would lead to a close approach on 25 December 2011. A Hubble Target of Opportunity proposal was activated to image the results of the interaction. We found that the original bright spot had faded dramatically before the HST observations had begun and the second bright spot was found to be a companion of a new dark spot on Uranus, only the second ever observed. Both spots exhibited variable drift rates during the nearly 5 months of tracking, and both varied in brightness, with BS1 reaching its observed peak on 26 October 2011, and BS2 on 11 November 2011. Altitude measurements based on near-IR imaging in H and Hcont filters showed that the deeper BS2 clouds were located near the methane condensation level (≈1.2 bars), while BS1 was generally ~500 mb above that level (at lower pressures). Large morphological changes in the bright cloud features suggest that they are companion clouds of possibly orographic nature associated with vortex circulations, perhaps similar to companion clouds associated with the Great Dark Spot on Neptune, but in this case at a much smaller size scale, spanning only a few degrees of longitude at their greatest extents.  相似文献   
100.
The seismic risk evaluation usually works with a fragmented concept of risk, which depends on the scientific discipline in charge of the assessment. To achieve an effective performance of the risk management, it is necessary to define risk as the potential economic, social and environmental consequences due to a hazardous phenomenon in a period of time. This article presents a methodology which evaluates the seismic risk from a holistic perspective, which means, it takes into account the expected physical damage and also the conditions related to social fragility and lack of resilience, which favour the second order effects when a hazard event strikes an urban centre. This seeks to obtain results which are useful in the decision making process for risk reduction. The proposed method for urban seismic risk evaluation uses the fuzzy sets theory in order to handle qualitative concepts and variables involved in the assessment, the physical risk level and aggravation level, related to the social fragility and the lack of resilience, are evaluated and finally a total risk level is determinate.  相似文献   
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