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91.
This paper is the first to address the suitability and potential of the cytochrome oxidase-1 (CO1) region of the parasitic marine nematode Anisakis simplex sensu stricto as a genetic marker. A. simplex s.s. is an ubiquitous parasite of many marine organisms and has been used as a ‘biological tag’ for population studies of pelagic fish stocks. The CO1 marker informs not only about nematode population structure but also about its hosts. The large CO1 sub-unit (∼800 bp) was analysed from third stage larvae of A. simplex s.s. from Atlantic herring, Clupea harengus L. caught off the north-west coast of Scotland. In total 161 A. simplex s.s. CO1 sequences were analysed from 37 herring that represented three spawning periods over 2 years. Overall very high haplotype and low nucleotide diversities were observed (h = 0.997 and π = 0.008, respectively). These results are in keeping with studies investigating parasitic nematodes of ungulates and are symptomatic of the high rate of substitutions accumulated by mtDNA and effective dispersal strategies of the parasite. The Tamura-Nei I + Г (Г = 1.2243) model of nucleotide substitution best suited the present data which were dominated by a high thymine bias and associated transitions. Large within population differences were highlighted by hierarchal AMOVAs with little variation related to spawning events or years which may indicate localised temporal stability. Temporal homogeneity in the CO1 gene coupled with the ubiquitous and widespread nature of the parasite indicates both the potential and limitations for its incorporation in stock-separation studies of its hosts. This work was carried out at the School of Biological Sciences, Liverpool University, Crown Street, Liverpool. L69 7ZB, UK.  相似文献   
92.
Quantifying the impact of alien invasive species on ecosystem services is an essential step in developing effective practices and policy for invasive species management. Here we develop a stochastic bioeconomic model that enables the economic impact of an invasive pest to be estimated before its arrival, based on relatively poorly specified ecological and economic parameters. We developed the model by using a hypothetical invasion of the varroa bee mite (Varroa destructor) into Australia and the negative flow-on effects that it would have on pollination by reducing honey bee populations, giving rise to a loss of pollination services, reduced crop yields, and additional production costs. If the mite were to continue to be prevented from entering the country over the next 30 years, we estimate that the economic costs avoided would be U.S. $16.4-38.8 million (Aus $21.3-50.5 million) per year. We suggest that current invasion response funding arrangements in Australia, which do not acknowledge these avoided damages, require amendment.  相似文献   
93.
Small changes in agricultural practices have a large potential for reducing greenhouse gas emissions. However, the implementation of such practices at the local level is often limited by a range of barriers. Understanding the barriers is essential for defining effective measures, the actual mitigation potential of the measures, and the policy needs to ensure implementation. Here we evaluate behavioural, cultural, and policy barriers for implementation of mitigation practices at the local level that imply small changes to farmers. The choice of potential mitigation practices relevant to the case study is based on a literature review of previous empirical studies. Two methods that include the stakeholders’ involvement (experts and farmers) are undertaken for the prioritization of these potential practices: (a) Multi-criteria analysis (MCA) of the choices of an expert panel and (b) Analysis of barriers to implementation based on a survey of farmers. The MCA considers two future climate scenarios – current climate and a drier and warmer climate scenario. Results suggest that all potential selected practices are suitable for mitigation considering multiple criteria in both scenarios. Nevertheless, if all the barriers for implementation had the same influence, the preferred mitigation practices in the case study would be changes in fertilization management and use of cover crops. The identification of barriers for the implementation of the practices is based on the econometric analysis of surveys given to farmers. Results show that farmers’ environmental concerns, financial incentives and access to technical advice are the main factors that define their barriers to implementation. These results may contribute to develop effective mitigation policy to be included in the 2020 review of the European Union Common Agricultural Policy.  相似文献   
94.
This paper provides a culturally-informed understanding of the impacts of climate change on a highly important subsistence activity that has been practiced by First Nations of central British Columbia for thousands of years. The paper begins with a review of the science regarding sockeye salmon and climate change. It discusses harvest patterns, and how the timing of runs has changed. A survey was conducted by the first author regarding St’át’imc traditional fishing at a historic site on the Fraser River, in 2005. The results show that the impacts of climate change are apparent to those conducting traditional fishing practices, in terms of changed timing and abundance of salmon runs. These perceptions fit closely with the information available from scientists and management agencies. These changes are highly problematic for the St’át’imc, in that the preservation method (drying) is tied to seasonal weather patterns. The whole cultural setting, and the relevance of salmon for subsistence would be highly altered by climate change that leads to changes in the timing and abundance of sockeye salmon. The paper discusses mitigation and adaptation alternatives, but also indicates the scope of these seem limited, given the resource systems and the context of these activities.  相似文献   
95.
This paper seeks to contribute to understanding of the factors associated with an effective emergent emergency response organisation and to provide new insights into this understudied area. It examines, through an analysis of a range of textual resources, the emergence and re‐emergence of the Student Volunteer Army (SVA) during the devastating earthquakes in Canterbury, New Zealand, in 2010–11. This evaluation is conducted in relation to the four key features of an effective emergency response organisation: adaptability; direction; leadership; and communication. In addition, the paper aims to further understanding of ‘emergency entrepreneurship’ and thus of the values and strategies that underpin social entrepreneur organisations in times of normalcy. The paper concludes that the unique position of the SVA as a ‘repeat emergent’ emergency response organisation enabled it to innovate continually and to improve repeatedly its systems, relationships, and image, such that it exhibited features common to emergent and established emergency response organisations.  相似文献   
96.
Snails of the genus Partula are highly endangered, with many species occurring solely in captivity. Captive populations experience periodic crashes, some of which have resulted in extinction. Pathologic investigations of the last individuals of a species that had undergone such a crash ( Partula turgida ) showed infection with a protozoan parasite as the cause of death. The parasite was identified as a member of the microsporidian genus Steinhausia , other members of which are known to cause mortality in aquatic pulmonate snails. We believe this is the first definitive report of an infectious disease causing the extinction of a species.

Extinción de una especie de Caracol Terrestre Debido a una Infección por un Parásito Microsporidio

Los caracoles del género Partula estan altamente amenazados junto con muchas especies existiendo únicamente en cautividad. Las poblaciones cautivas experimentan colapsos periódicos, algunos de los cuales han resultado en extinciones. Investigaciones patológicas de los últimos individuos de una especie que ha pasado por este tipo de colapso ( Partula turgida ) muestran infecciones de un protozoario parásito como la causa de su muerte. El parásito ha sido identificado como un miembro del género Steinhausia , otros miembros de este género han sido identificados como los causantes de mortalidades en caracoles pulmonados acuáticos. Creemos que este es un reporte definitivo de una enfermedad infecciosa causante de la extinción de una especie.  相似文献   
97.
We report reptile and arboreal marsupial responses to vegetation planting and remnant native vegetation in agricultural landscapes in southeastern Australia. We used a hierarchical survey to select 23 landscapes that varied in the amounts of remnant native vegetation and planted native vegetation. We selected two farms within each landscape. In landscapes with plantings, we selected one farm with and one farm without plantings. We surveyed arboreal marsupials and reptiles on four sites on each farm that encompassed four vegetation types (plantings 7-20 years old, old-growth woodland, naturally occurring seedling regrowth woodland, and coppice [i.e., multistemmed] regrowth woodland). Reptiles and arboreal marsupials were less likely to occur on farms and in landscapes with comparatively large areas of plantings. Such farms and landscapes had less native vegetation, fewer paddock trees, and less woody debris within those areas of natural vegetation. The relatively large area of planting on these farms was insufficient to overcome the lack of these key structural attributes. Old-growth woodland, coppice regrowth, seedling regrowth, and planted areas had different habitat values for different reptiles and arboreal marsupials. We conclude that, although plantings may improve habitat conditions for some taxa, they may not effectively offset the negative effects of native vegetation clearing for all species, especially those reliant on old-growth woodland. Restoring suitable habitat for such species may take decades to centuries.  相似文献   
98.
99.
Warmwater fish habitat in the San Juan River of the southwestern United States has been reduced by over 30% as a result of water depletion, reservoir inundation, and cold-water dam releases combined with drought-related changes in hydrology. This reduction and a suite of other factors have contributed to declines in native fish populations including the federally endangered Colorado Pikeminnow (Ptychocheilus lucius) and Razorback Sucker (Xyrauchen texanus). Conservation efforts for these species include determining flow needs; protecting, managing, and augmenting habitats; and stocking hatchery fish. But the young of stocked fish have low survival due largely to a paucity of nursery habitat not being reformed and maintained under current conditions. Flow recommendations for Navajo Dam releases designed to mimic the river's natural hydrograph have not been met due to water shortages, and the desired outcomes of increased channel complexity and enhanced fish habitat have not been observed. Forecasted hydrology that includes ongoing drought shows that achieving the flow targets through further dam reoperations is unlikely. Mechanical construction of early life-stage habitats is a highly recommended complement to flow management for offsetting the effects of flow reduction and habitat loss. Habitats with features that are effective and resilient under a range of flows are important in counterbalancing the effects of climate change.  相似文献   
100.
The Shale Network is a group of stakeholders collating, publishing, and conducting research on water quality data collected in the northeastern United States experiencing natural gas extraction from shale using hydraulic fracturing. In developing the Shale Network, we have experienced reluctance to share data from all participating sectors. This paper explores this reluctance, identifying barriers to greater collaboration among multiple stakeholders in natural resource management projects. Findings are derived from participant observation of the Shale Network team, surveys conducted during Shale Network workshops, interviews with water quality stakeholders, and participant observation of water quality monitoring training sessions. The barriers identified include perceptions about data problems and quality, technical capacity, regulatory and legal limitations, competition for resources, and resource allocation decisions. This paper identifies strategies the Shale Network has used to overcome data-sharing barriers to expand a culture of data sharing that supports enhanced nature resource management and citizen engagement.  相似文献   
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