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671.
Strategies to reduce, halt, and reverse global declines in marine biodiversity are needed urgently. We reviewed, coded, and synthesized historical and contemporary marine conservation strategies of the Kitasoo/Xai'xais First Nation in British Columbia, Canada to show how their approaches work. We assessed whether the conservation actions classification system by the Conservation Measures Partnership was able to encompass this nation's conservation approaches. All first-order conservation actions aligned with the Kitasoo/Xai'xais First Nation's historical and contemporary marine conservation actions; hereditary chief management responsibility played a key role. A conservation ethic permeates Kitasoo/Xai'xais culture, and indigenous resource management and conservation existed historically and remains strong despite extreme efforts by colonizers to suppress all indigenous practices. The Kitasoo/Xai'xais's embodiment of conservation actions as part of their worldview, rather than as requiring actions separate from everyday life (the norm in nonindigenous cultures), was missing from the conservation action classification system. The Kitasoo/Xai'xais are one of many indigenous peoples working to revitalize their governance and management authorities. With the Canadian government's declared willingness to work toward reconciliation, there is an opportunity to enable First Nations to lead on marine and other conservation efforts. Global conservation efforts would also benefit from enhanced support for indigenous conservation approaches, including expanding the conservation actions classification to encompass a new category of conservation or sacredness ethic.  相似文献   
672.
673.
Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree-focused approach, the zoological community has established an inter-institutional infrastructure to support long-term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree-based population management tool that incorporates life-history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species.  相似文献   
674.

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.

  相似文献   
675.
Ambio - Muskoxen (Ovibos moschatus) are an integral component of Arctic biodiversity. Given low genetic diversity, their ability to respond to future and rapid Arctic change is unknown, although...  相似文献   
676.
Steroid estrogens such as estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) have been suspected to be the main contaminants, which can affect the endocrine system of animals. Many authors have investigated these chemicals in the domestic wastewater treatment plants (WTP). However, wastewater from industries producing steroid contraceptives has not got ample attention. From the environmental point of view, the four steroids are very significant because even very low concentrations (ng/L) can cause reproductive disturbances in human, livestock and wildlife. The main purpose of the present investigation was to develop an analytical method for the determination of the four steroid estrogens present in WTP of a pharmacy factory, mainly producing contraceptive medicine in Beijing, China. Analysis was performed by solid-phase extraction (SPE) system and liquid chromatography combined with tandem mass spectrometry (LC/MS/MS). The average recoveries from effluent samples ranged from 88% to 103% and the precision of the method ranged from 9% to 4%. Based on 0.5-L wastewater samples, the limit of quantification (LOQ) was determined at 0.7 ng/L for E1, 0.8 for E2, 0.9 ng/L for E3, and 0.5 ng/L for EE2 in influent, and 1.0 ng/L for E2 and EE2, and 2.0 ng/L for E1 and E3 in effluent. In the influent samples, average concentrations of 80, 85, 73 and 155 ng/L were determined for E1, E2, E3 and EE2, respectively, showing that they were removed in this WTP to the extent of 79, 73, 85 and 67%, respectively.  相似文献   
677.
The rapidly developing Asian countries may face threatening environmental contamination, that however remains largely unassessed. We studied persistent trace elements in three wetlands, Poyang Lake, relatively unpolluted, and Tai Lake, and Pearl River Delta, selected as hotspots of pollution in Central China. We adopted as indicator the Little Egret, a widespread colonial waterbird, and during 1999 and 2000 we collected and analysed the same samples as for a parallel study we conducted in Pakistan, e.g. eggs, body feathers of chicks, prey spontaneously regurgitated by the chicks, and sediments at the areas most used by foraging egrets. The levels of trace-metals at our three study areas were similar, or within the range, of those found in the few other studies for East Asia, with few exceptions. The concentrations of the various elements were below the threshold that may affect the survival or reproduction of the birds, and even the highest concentrations relative to background, i.e. Se in eggs, and Hg in feathers at Pearl Delta, do not pose toxic hazards. In sediments, the levels of trace elements were lower than the critical levels assumed for contaminated soil, except for alarming high levels of As at Poyang. These results do not confirm our expectation, that Poyang was relatively uncontaminated, while Tai and Pearl were polluted. Although trace metal concentration differed significantly among the three study areas, these differences were minor and were not consistent among elements and samples. The bioaccumulation ratios from sediments through prey, feather and egg, were consistent with our previous findings for Pakistan. Only Hg exhibited high bioaccumulation, while Se and Zn had low accumulation, and the other elements no accumulation. This reasserts that feathers of predators such as egrets, may be more sensitive indicators of environmental contamination for the elements subject to bioaccumulation, whereas the sediments or the organisms low in the food chain are better indicators for the other elements.  相似文献   
678.
Individuals of the crayfish Procambarus clarkii (males and females) were exposed simultaneously to cadmium and zinc during 21 days. Exposure concentrations were those determined at the Guadiamar river after the Aznalcóllar mining spill (SW, Spain): 10 and 30 μg L−1 of cadmium and 1000 and 3000 μg L−1 of zinc. Three biomarkers (MT: metallothioneins like proteins, VTG: vitellogenin/vitellin like proteins and histopathology) together with heavy metal bioaccumulation were determined in soft tissues of male and female P. clarkii. At the concentrations tested, increasing cadmium exposure resulted in increasing cadmium bioaccumulation and increasing subletal effects (induction of MT, VTG and histopathological damage in tissues). Nevertheless, although increasing zinc exposure showed increasing VTG induction and histopathological damages, not a positive relationship was determined with MT induction. Concerning to responses determined in male and female crayfishes only differences were found between sexes at the highest cadmium exposure concentration related to bioaccumulation in hepatopancreas tissues. Biomarkers responses to heavy metal contamination in this crayfish, even VTG induction not before tested in heavy metal contamination assessment in crustaceans resulted potential tools for the monitoring of heavy metal environmental contamination.  相似文献   
679.
Urban trees serve important environmental, social and economic functions, but similar to other natural endowments they are not customarily depicted in monetary terms. The needs to augment protection, funding and community support for urban greening call for proper valuation. Heritage trees (HTs), the cream of urban-tree stock, deserve special attention. Existing assessment methods do not give justice to outstanding trees in compact cities deficient in high-caliber greenery, and to their social-cultural-historical importance. They artificially separate evaluation from valuation, which should be a natural progression from the former. Review of tree valuation methods suggested the formula approach to be more suitable than contingent valuation and hedonic pricing, and provided hints on their strengths and weaknesses. This study develops an alternative formulaic expert method (FEM) that integrates evaluation and valuation, maximizes objectivity, broadly encompasses the key tree, tree-environment and tree-human traits, and accords realistic monetary value to HTs. Six primary criteria (dimension, species, tree, condition, location, and outstanding consideration) branched into 45 secondary criteria, each allocated numerical marks. Each primary criterion was standardized to carry equal weight, and a tree's maximum aggregate score is capped at 100. A Monetary Assignment Factor (MAF) to consign dollar value to each score unit was derived from three-year average per m2 sale price of medium-sized residential flats. The applicability of FEM was tested on selected HTs in compact Hong Kong. The aggregate score of a tree multiplied by MAF yielded monetary value, which was on average 66 times higher than the result from the commonly-adopted Council of Tree and Landscape Appraisers method. The computed tree values could be publicized together with multiple tree benefits to raise understanding and awareness and rally support to protect HTs. The property-linked FEM could be flexibly applied to other cities, especially to assess HTs in compact developing cities.  相似文献   
680.
Abstact The present study was designed to evaluate indirect, non-invasive, on-line measurement of biofilm thickness using an electrical capacitance technique. Several assays were carried out and the results showed that, at a frequency of 1 kHz, electrical capacitance could be used to measure biofilm thickness indirectly (with a correlation coefficient of 0.9495). The reproducibility revealed by the assays was also highly satisfactory.However, in contrast to what was expected, there was an inverse relationship between electrical capacitance and biofilm thickness, i.e. electrical capacitance diminished with the increase in the biofilm thickness.The tests were also carried out at different frequencies (1 kHz, 10 kHz and 100 kHz)  相似文献   
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