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11.
McMahon C  van den Hoff J  Burton H 《Ambio》2005,34(6):426-429
This study addresses the consequences of repeated human handling on the survival of an endangered phocid, the southern elephant seal and the implications for wildlife research. Southern elephant seal pups were repeatedly handled during the first six weeks of their lives. The possibility that such anthropogenic research may have altered the very parameters that were being investigated is a topical and relevant study area that we address here. Our results show that there were no measurable effects on pups that were repeatedly handled and subjected to invasive research methods with respect to survivorship in the short term (the 24-day nursing period) nor in the long term (the first year of life and beyond) and hence fitness one year after handling. In support of this conclusion we were unable to detect any significant differences in the survival rates of the most intensively handled seals and the least intensively handled seals.  相似文献   
12.
Some Lessons Learned from Public Health on the Process of Adaptation   总被引:1,自引:1,他引:0  
Lessons learned from more than 150 years of public health research and intervention can provide insights to guide public health professionals and institutions as they design and implement specific strategies, policies, and measures to increase resilience to climate variability and change. This paper identifies both some modifications to public health systems that may enhance adaptive capacity, and lessons drawn from the history of managing environmental and other threats in the public health sector that may have relevance for other sectors as they design approaches to increase their adaptive capacity to more effectively cope with climate variability and change. The views expressed are the author’s own and do not represent official US EPA policy.  相似文献   
13.
The effect of aging on the solid/pore-water partitioning and desorption behaviour of tributyltin (TBT) in sediments was examined. Three sediment samples with contrasting physical and chemical properties were spiked with 10 mg/kg TBT and aged under sterile conditions for periods of time ranging from 1 to 84 days. Aging had a negligible effect on partitioning and desorption behaviour in a sandy sample with very low organic carbon content (0.2% w/w). In contrast, for samples with larger amounts of organic carbon (2.6% and 4.8% w/w), aging caused substantial increases in TBT sorption. For these samples, apparent distribution coefficients (KD,app) obtained from sequential 2 h desorption experiments also exhibited a twofold increase between spiked sediments subjected to aging for 1 day and 84 days. This study demonstrates that aging effects may be an important aspect of TBT fate in contaminated sediments.  相似文献   
14.
Despite high potential for dispersal, the purple sea urchin Strongylocentrotus purpuratus was found to have significant genetic subdivision among locations. Ten geographic locations along the coast of California and Baja California were sampled between 1994 and 1995. Samples from some locations included both adult and recruit urchins. Allozyme analyses revealed a genetic mosaic, where differentiation over short geographic distances could exceed differentiation over much larger distances. Significant allozyme differentiation was found among subpopulations of adults (standardized variance, F ST =0.033), among subpopulations of recruits (F ST =0.037), and between adults and recruits from the same location. DNA-sequence data for the mitochondrial cytochrome oxidase I gene also showed significant heterogeneity among locations, with a mild break in haplotype frequencies observed 300 km south of Point Conception. California. Repeated sampling over time is necessary to determine whether these patterns of differentiation are stable and to begin to understand what forces produce them.  相似文献   
15.
The distribution and enrichment of selected trace metals (Cd, Cr, Cu, Ni, Pb, Sn, Zn) in benthic sediments of the Southport Broadwater, a semi-enclosed coastal body of water adjacent to the Gold Coast city, south-eastern Queensland, Australia, was studied with the objective of assessing the extent and degree of sediment contamination. Sediment samples from the 0–10 cm and 10–20 cm depth intervals of 32 sites within the Southport Broadwater and surrounding residential canals were analysed for particle size distribution, pH, organic C and ‘near-total’ major (Al, Ca, Fe, Mn) and trace (Cd, Cr, Cu, Ni, Pb, Sn, Zn) metal contents. Sediment contamination for each trace metal was assessed by (1) comparison with Australian sediment quality guidelines, (2) calculation of the index of geoaccumulation based on regional background values, and (3) geochemical normalisation against Al (i.e. the abundance of alumino-silicate clay minerals). Based on this approach, the results indicate that submerged sediments in the study area are not presently enriched with Cd, Cr or Ni, with the spatial distribution of these metals being very well explained by the abundance of alumino-silicate clay minerals. However, several sites were strongly enriched with Cu, Pb, Sn and Zn, arising from sources related to either urban runoff or vessel maintenance activities. The study indicates that several varying approaches are needed for a satisfactory assessment of contaminant enrichment in estuarine sediments.  相似文献   
16.
The broad objective of this special issue of Mitigation and Adaptation Strategies for Global Change is to address some of the gaps in our knowledge and understanding of the policies, programs, and measures that might be applied to natural hazards and their impacts in an era of climate change. Given the global impacts of climate change and world-wide pattern of increasing losses from natural hazards we necessarily adopt an international perspective. The specific goals of the special issue are to: (a) encompass experiential aspects, emphasizing current practice of mitigation and its associated measures, and their results; and (b) explore primary or root causes of alarming shifts in human and economic costs of environmental extremes. Special emphasis is placed on how human activities are playing a key role in enhancing vulnerability to NTEE (nature-triggered environmental extremes), quite independently from the anthropogenic causes of climate change. The goals are also (c) to examine costs, risks, and benefits (of all kinds including social, political, ecological) of mitigation, and adjustment and adaptation measures; and (d) analyze policy implications of alternative measures. These components are expected to make significant contributions to policy considerations – formulation, implementation and evaluation. There is much uncertainty about the rate of climate change; however, the fact of increase of the atmospheric temperature in the last century is no longer a subject of scientific or policy debate. Due to such changes in the geophysical parameters, certain types of nature-triggered environmental extreme events are likely to continue to increase. How global warming will affect regional climates and pertinent variables is not well known, limiting our ability to predict consequential effects. This factor poses serious constraints against any straightforward policy decisions. Research findings of the work of this volume reaffirm that human dimensions, specifically our awareness and decision-making behavior, are powerful explanatory factors of increasing disaster losses. Disaster mitigation through addressing human, social, and physical vulnerability is one of the best means for contributing to ‘climate change adaptation plans’, and sustainable development goals. Recent lessons from various countries have depicted that the formulation of mitigation strategies cannot be exclusively top-down as it requires social, political, and cultural acceptance and sense of ownership. An interactive, participatory process, involving local communities, produces best expected outcomes concerning mitigation, preparedness, and recovery. An emerging consensus is that there is a need to move towards the ‘mission’ of the International Strategy for Disaster Reduction which aims at building disaster resilient communities by promoting increased awareness of the importance of disaster reduction as an integral component of sustainable development, with the goal of reducing human, social, economic and environmental losses due to natural hazards and related technological and environmental disasters. Sharing of best practices and lessons globally is certain to produce more efficiency and understanding in policy and decision making.  相似文献   
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Understanding how population density influences mating systems may lead to important insights into the plasticity of breeding behavior, but few natural systems allow for such studies. Antarctic fur seals (Arctocephalus gazella) provide an interesting model system because they breed in colonies of varying densities. Previous studies have largely focused on a high-density site at Bird Island, South Georgia. Here, 13 highly polymorphic microsatellite loci were used to conduct a genetic analysis of a low-density breeding colony of this species at Livingston Island, approximately 1,600 km south of South Georgia. The majority of adults seen ashore (n?=?54) were sampled together with every pup born (n?=?97) over four consecutive years. Paternities were confidently assigned for 34 out of the 97 pups. Two out of 23 sampled males accounted for the paternity of 28 % of all pups sampled during the study and 82 % of the pups with an assigned father. Moreover, a full likelihood pedigree inference method assigned a further eight paternities to a single unsampled male seal that is inferred to have held a territory during the season before the study began. The most successful males in our study easily surpassed the previous record for the total number of pups sired per male seal for the species. Furthermore, we identified two triads of full siblings implying that their parents remated in three consecutive years. These findings suggest that territorial male fur seals may achieve greater success in monopolizing access to breeding females when population density is relatively low.  相似文献   
20.
ABSTRACT

Civil society’s potential as a force for solving complex societal problems – particularly those that require a challenge to the status quo – has provoked practical and theoretical interest, with its potential largely reliant on the perception that it is a ready if variable source of social capital resources. However, there are no guarantees that civil society will use its social capital for the greater good. Civil society encompasses a range of groups, some more inward-looking and oriented to private interests, and others more outward-looking and oriented to public interests. This divergent character of civil society was evident in the three campaigns for greenspace protection that eventually led to the creation of the Toronto region greenbelt, where civil society organisations (CSOs) from both growth and conservation camps contended for influence, each succeeding at different times. But over time (a time when state actors were increasingly in need of non-state partners to help solve complex governance problems), coalitions of environmental CSOs in the three campaigns – to protect the Niagara Escarpment, Oak Ridges Moraine and surrounding countryside – became more effective at influencing government to protect greenspace. A comparison of the coalitions using a framework based on key attributes of CSOs – missions and memberships – suggests that the environmental coalitions were more effective when they recruited more members with a diverse set of resources arising from both bonding and bridging social capital. In general, the more inclusive and public-interested the CSOs, the more effective the challenge to the status quo.  相似文献   
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