Anaerobic digestion of livestock and poultry manures spiked with tetracycline antibiotics

Abstract

We investigated the anaerobic degradation of tetracycline antibiotics (tetracycline [TC], oxytetracycline [OTC] and chlortetracycline [CTC]) in swine, cattle, and poultry manures. The manures were anaerobically digested inside polyvinyl chloride batch reactors for 64?days at room temperature. The degradation rate constants and half-lives of the parent tetracyclines were determined following first-order kinetics. For CTC the fastest degradation rate was observed in swine manure (k?=?0.016?±?0.001 d^?1; half-life = 42.8?days), while the slowest degradation rate was observed in poultry litter (k?=?0.0043?±?0.001 d^?1; half-life = 161?days). The half-lives of OTC ranged between 88.9 (cattle manure) and 99.0?days (poultry litter), while TC persisted the longest of the tetracycline antibiotics studied with half-lives ranging from 92.4?days (cattle manure) to 330?days (swine manure). In general, the tetracyclines were found to degrade faster in cattle manure, which had the lowest concentrations of organic matter and metals as compared to swine and poultry manures. Our results demonstrate that tetracycline antibiotics persist in the animal manure after anaerobic digestion, which can potentially lead to emergence and persistence of antibiotic resistant bacteria in the environment when anaerobic digestion byproducts are land applied for crop production.     

International Trade Status and Crisis for Snake Species in China

Abstract:  In recent years, the purchase of snakes for leather, food, and traditional medicine has increased in China, which has greatly reduced certain snake populations. Trade records show that since the 1990s, with respect to some species of snakes, China is changing from a net export country to a net import country. We analyzed data on international trade in snake species, concentrating, in particular, on trade dynamics and species composition. The overall number of snakes exported appears to have decreased in the last 10 years. However, the number of snakes imported during this period has increased steadily. Many species of snakes that are traded in significant numbers are endangered or threatened species. To conserve snakes in China, we recommended that the Chinese government and the international conservation community take the following actions: enhance legislation and list several species in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) appendices; register all snake farms in China; carry out population and market surveys; monitor the dynamics of trade; encourage biological research; encourage change in food habits; and enhance cooperation between Hong Kong and mainland China.     

Protected Areas and Prospects for Endangered Species Conservation in Canada

Abstract:  Reserve networks figure prominently in conservation strategies that aim to reduce extinction rates. We tested the effectiveness of the current reserve network at protecting species at risk in Canada, where relatively extensive wilderness areas remain. We compared numbers of terrestrial species at risk included in existing reserves to randomly generated networks with the same total area and number of reserves. Existing reserve networks rarely performed better than randomly selected areas and several included fewer endangered species than expected by chance, particularly in the most biologically imperiled regions. The extent of protected area and density of species at risk were unrelated at either broad (countrywide) or finer spatial scales (50 × 50 km grids), although there was a tendency for the most threatened regions of the country to have few or no protected areas (1.5% of areas with >30 endangered species were in reserves). Although reserves will play a useful role in conserving endangered species that occur within them, reducing extinction rates in a region with much of the world's remaining wilderness will require integrating conservation strategies with agricultural and urban land-use plans outside formally protected areas.     

寿昌江流域及邻近山区溶岩洞穴大型水生底栖动物

灵栖洞、灵山洞、瑶琳洞为浙江西部山区已开发的著名观光溶岩洞穴群，灵栖洞位于寿昌江流域支流小江溪的源头附近，由灵泉、清风、霭云三洞组成，灵山洞由清虚洞、仙桥洞组成．三洞穴群内大型水生动物隶属2门3纲5目11科．灵栖洞大型水生动物群落主要由放逸短沟蜷和掌指米虾组成，灵山洞主要由硬环棱螺、放逸短沟蜷、格氏短沟蜷及水生昆虫幼体组成，瑶琳洞内主要由锯齿新米虾和扁卷螺组成．灵泉洞洞穴有光带主要分布有掌指米虾和放逸短沟蜷，弱光带主要分布有锯齿新米虾、掌指米虾和硬环棱螺，黑暗带主要分布有锯齿新米虾、掌指米虾和扁卷螺，灵泉洞有光带动物种类的多样性、均匀度指数最高，分别为0．9832和0．6109，黑暗带最低，分别为0．0983和0．1418；优势度在黑暗带最高，其值为0．6250．表3参18     

Using Niche-Based Models to Improve the Sampling of Rare Species

Abstract:  Because data on rare species usually are sparse, it is important to have efficient ways to sample additional data. Traditional sampling approaches are of limited value for rare species because a very large proportion of randomly chosen sampling sites are unlikely to shelter the species. For these species, spatial predictions from niche-based distribution models can be used to stratify the sampling and increase sampling efficiency. New data sampled are then used to improve the initial model. Applying this approach repeatedly is an adaptive process that may allow increasing the number of new occurrences found. We illustrate the approach with a case study of a rare and endangered plant species in Switzerland and a simulation experiment. Our field survey confirmed that the method helps in the discovery of new populations of the target species in remote areas where the predicted habitat suitability is high. In our simulations the model-based approach provided a significant improvement (by a factor of 1.8 to 4 times, depending on the measure) over simple random sampling. In terms of cost this approach may save up to 70% of the time spent in the field.     

Using Economic and Regulatory Incentives to Restore Endangered Species: Lessons Learned from Three New Programs

Abstract:  We studied three new incentive-based programs for restoring endangered species on private lands in the United States: safe harbor, Environmental Defense's Landowner Conservation Assistance Program, and conservation banking. For each program, we gathered data on the number of participating landowners, the number of species targeted for assistance, and the cumulative acreage of enrolled land. Measured in this way, both safe harbor and the Landowner Conservation Assistance Program have been remarkably successful. Landowners are drawn to three aspects of these programs: (1) the removal of regulatory burdens associated with attracting endangered species to their property; (2) technical guidance on how to restore habitats for endangered species; and (3) cost-share assistance for habitat restoration. Technical guidance appears to be more important than either regulatory relief or financial assistance in securing the cooperation of some landowners. Assessing the success or failure of conservation banking proved more difficult, given the relatively small number of banks created to date and the lack of any centralized database on them. However, nearly half of the 47 endangered-species conservation banks we surveyed have sold credits, indicating some success in either acquiring or restoring essential habitats.     

核糖体RNA基因在海洋动物分子系统学中的应用

随着分子遗传标记在分子系统学中应用的发展,核糖体RNA基因因其特殊的组成结构和演化方式被广泛应用于海洋动物分子系统学研究中.本文系统地介绍了真核生物核糖体RNA基因的组成和性质及其近年来在海洋动物系统进化、分类和种质鉴定、遗传多样性研究等方面研究中的应用.从中可以看出,核糖体RNA基因已经广泛应用于海洋动物的分子系统学研究中,但主要利用的是核糖体RNA基因的一级结构.图2参36     

Bush Tucker, Bush Pets, and Bush Threats: Cooperative Management of Feral Animals in Australia's Kakadu National Park

Abstract:  Although feral animal management is often based on the proposition that introduced species threaten ecological and conservation values, that view is not necessarily shared by all stakeholders, including those indigenous people who own and co-manage Kakadu National Park with Australia's federal government. Drawing on field-based interviews with the Jawoyn people, we found that these indigenous people categorize water buffalo (  Bubalus bubalis ) as an important food source (tucker), view horses (  Equus caballus ) as bush pets, and consider pigs (  Sus scrofa ) a threat to their lands. As a result, Jawoyn people want more water buffalo in the park, have high tolerance of environmental damage caused by horses, and are open to the idea that pig population densities should be reduced. Jawoyn also advocate an adaptive and participatory approach to feral animal control so that the consequences of any management actions can be properly understood before irrevocable change occurs. These findings highlight one example of how indigenous people's ecological knowledge has adapted in response to changing landscapes and community aspirations. Co-management strategies that aim to incorporate the dynamics of indigenous people's views need to start with issues on which there is agreement between different groups and take a cautious approach to joint exploration of more contentious issues. That approach should include ongoing and on-site monitoring so that the consequences of management actions can be properly understood and comprehensively negotiated by all parties.