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1.
丹江口水库库区水生生物调查和渔业利用的意见   总被引:5,自引:0,他引:5  
丹江口水库除了用于防洪、发电、航运、灌溉之外,用以发展渔业也是综合利用主要项目之一。党的八届六中全会提出了实现农林牧副渔的农业全面大革命的号召,而丹江口水库如此大的面积用来发展渔业,正是极有意义的事。这不仅可以提供大量的鱼产品来满足和丰富人民日益增长的需要,而且可以获得较大的经济收益支援国家的工业建设。  相似文献   

2.
研究氯对鱼类、蚤类及藻类的急性及亚致死毒性,从急性试验结果看,氯的性随温度的上升而提高。亚致死毒性研究了氯对大型蚤的生殖,白鲢幼鱼的鳃组织学,血液学的变化,白鲢幼鱼的迥避反应及对鲤鱼吸收的影响等,结果说明,氯对水生生物的亚致死死效应不尽相同,不同的生物种,不同的生理指标,氯的亚致死效率与温度的关系也不同,反映出这种毒性效应的复杂性,两者之间并没有固定的相关关系。在亚致死效应中大型蚤的生殖及白链的血液指标对氯最为敏感,据此作者对我国保护水生生物的氯的水质标准提出了一些建议。  相似文献   

3.
长江三峡水库库区水生生物调查和渔业利用的规划意见   总被引:8,自引:0,他引:8  
随着我国社会主义建设事业的飞跃发展,水利工程到处在兴建。伟大的长江流域规划也将逐步实现。特别是三峡大坝的建筑将形成一个发电、防洪、运输、灌溉和渔业等综合利用的大型水库。  相似文献   

4.
在长江流域规划的宏伟远景中,除了修建三峡水利枢纽这一举世瞩目的重大工程外,尚要在长江上游各支流中兴修许多大大小小的水库,形成一个梯级的水库群。例如,在岷江的干流中,就已有灌县鱼嘴和紫平铺两个水库开工修建,而计划修建的还有好几个水库,偏窗子水库即是其中之一。这些水库,除了具有蓄洪以减轻三峡水利枢纽负荷的作用,又可利用于发电、灌溉和交通运输外,同时,在渔业上也具有极其重大的意义,这是不能忽视的。  相似文献   

5.
海洋生物多样性保护是《生物多样性公约》的重要领域。本文梳理了海洋生物多样性保护相关议题的发展脉络,分析了保护形势的变化,认为海洋生物多样性保护无论是在工作领域还是在战略目标方面都取得了较大发展。工作领域方面,从最初仅关注海洋生物多样性的现状,逐渐拓展到识别海洋生物多样性的威胁因素,以及探讨解决这些威胁因素的工具和方法上。战略目标方面,从保护10%的海洋目标提升到至少保护30%的海洋区域。特别是将国家管辖范围以外区域海洋生物多样性这一热点问题也纳入到议题的讨论范畴。结合科学研究文献和国际进程评估报告对相关议题进展进行了评估,认为在工作领域上,目前海洋生物多样性保护相关议题更侧重减少海洋生物多样性威胁,在工具和方法上较为欠缺。在战略目标上,不仅要实现30%的数量目标,还需要考虑科学地保护规划和利用。在处理国家管辖范围以外区域海洋生物多样性问题上,需要明确《生物多样性公约》的作用。通过对议题的梳理和评估,识别出目前海洋生物多样性保护面临的主要挑战,包括:(1)各国政府及利益攸关方政治意愿和行动力不强;(2)全球海洋受保护区域面积不足,保护成效较低;(3)资金来源不够;(4)海洋生物多样性保护...  相似文献   

6.
中国履行生物多样性公约的成就和展望   总被引:9,自引:0,他引:9       下载免费PDF全文
王献溥  郭柯   《广西植物》2006,26(3):249-256
2004年是生物多样性公约实施10周年。中国于1993年1月7日作为第7个国家正式加入“公约”。接着就由国家环境保护总局牵头组建国家履约协调组和许多联络点,下设办公室负责日常工作。可见,国家对生物多样性工作的重视和认真的态度。10年来,中国在履约方面做了大量工作,成绩显著。例如,完成了“中国生物多样性国情研究报告”和“中国生物多样性保护行动计划”等一大批重要文件,建立了“生物多样性委员会”、“生物多样性保护基金会”和相应的科学与教育部门,开展了许多科研项目和讲授相关的课程,出版了系列丛书和“中国生物多样性”学术刊物,重视开展学术交流,建立了生物多样性数据库和相关的管理政策,生物多样性保护实体和产业日益增加和发展等就是明显的事例。履约10年的经验在于下列三个方面(1)保护和发展必须密切结合;(2)“统一协调、分散管理”的方针需要进一步完善;(3)基础性和综合性研究需要加强。展望未来,只有在加强基础和综合研究以及提高管理水平方面下一番功夫,履约工作才能取得更大的成绩。  相似文献   

7.
酸雨对水生生物影响的研究   总被引:5,自引:0,他引:5       下载免费PDF全文
环境生物学家目前面临的任务之一是就酸雨对水体和水生生物的冲击作出预测。本文主要介绍酸雨分布最广、危害严重的地区,并对水生生物的影响作出分析。研究表明一个湖泊及其流域中和酸雨所进入的酸的容量,主要取决于汇水区基岩的组成。湖、河酸化所带来的最明显的生物学冲击是鱼类种群的消失或减少。而食物网中各个营养级的生物也可能受到影响。生物的数量和种类会减少,结果随着整个水生态系统的破坏,水体的初级生产力和分解作用受到伤害。 我们所进行的研究表明:鲢、餹、鲤对酸的相对敏感性是受精卵>鱼苗>鱼种;鲢鱼的96小时LC_(50)分别是pH5.34,4.51及3.80。酸雨对大型溞的急性毒性,24小时LC_(50)是pH4.06±0.19;48小时LC_(50)是pH4.94±0.20。椭园萝卜螺对酸的96小时累积死亡率分别是:pH3.6时100%,pH3.8时60%,pH4.0时20%以及pH4.2时10%。 作者对今后需要进行的研究课题提出了建议。  相似文献   

8.
三氯异氰尿酸和环丙沙星对水生生物的急性毒性   总被引:7,自引:0,他引:7  
王翔  聂湘平  李凯彬 《生态科学》2006,25(2):155-157,161
研究了三氯异氰尿酸(TCCA)和盐酸环丙沙星(CPFX)对小球藻、大型溞和稀有鮈鲫的急性毒性。毒性试验结果表明,TCCA和CPFX对小球藻的96hEC50分别为0.31mg·L-1和20.61mg·L-1、对大型溞48hLC50分别为0.19mg·L-1和135.15mg·L-1,TCCA对稀有鮈鲫96hLC50为1.76为mg·L-1,CPFX对稀有鮈鲫不产生急性毒性。对于TCCA,大型溞最敏感,小球藻次之,稀有鮈鲫最不敏感;对于CPFX,小球藻最敏感,大型溞次之,稀有鮈鲫最不敏感。  相似文献   

9.
气候变化、生物多样性及生物资源等方面的热点研究越来越多地涉及到水生生物,<濒危野生动植物种国际贸易公约>(CITES)也日益关注水生野生动物的贸易管理问题.自CITES第九届缔约国大会以来,CITES附录物种的讨论中越来越多地出现水生生物种类,有关的管理机制正在不断完善之中.中国是水生生物的利用大国,CITES对水生生物贸易的管理将会对我国产生深远影响.本文对CITES中水生生物的管理情况进行了回顾,同时结合公约第十四届缔约国人会的最新信息,分析了目前的热点问题,探讨了其对我国水生生物管理的影响.分析结果表明,CITES对水生生物的管理正在不断扩展,力度不断增强,CITES正趋于参与商业开发水生物种的管理.有鉴于此,建议加强水生生物资源利用及管理方面的基础性研究,为资源保护、可持续利用及国家制订公约履约策略提供依据.  相似文献   

10.
随着社会主义建设的大跃进,全国到处兴建水利工程。北京怀柔水库提前4年于1958年3月9日开工,同年6月20日完工。为北京1958年继十三陵水库之后的第二座水库。  相似文献   

11.
For the conservation of the diving beetle, Dytiscus sharpi (Wehncke) (Coleoptera: Dytiscidae), which is included in the Red List of Japan, it is critical to understand its ecological background. In the present study, oviposition preference and hatchability were investigated under laboratory conditions. Possible candidates of oviposition plants were observed in the natural breeding habitats of D. sharpi. Eight aquatic plants were identified, and Oenanthe javanica (Blume) was the major species present in March, when first instar larvae appeared. The number of eggs laid was investigated under the following conditions: (i) eight field plants were authentically recreated at a similar covering rate to that in the natural habitat; (ii) each of the eight plants was set at the same covering rate; (iii) a single plant taken from the field was placed separately. Significant oviposition preference for O. javanica was found when these eight aquatic plants were present in the same aquaria. In addition, hatchability in O. javanica was significantly higher than that in any of the other plants. These results suggest that O. javanica is an important aquatic plant for oviposition by D. sharpi.  相似文献   

12.
    
The intentional introduction of native cold-water trout into high-elevation fishless lakes has been considered a tool to build resilience to climate change (i.e., assisted colonization); however, ecological impacts on recipient communities are understudied. The purpose of this study was to inform native cold-water trout recovery managers by assessing potential consequences of translocating a regionally native trout (westslope cutthroat trout; Oncorhynchus clarkii lewisi) into fishless mountain lakes. This study compared littoral benthic invertebrate richness, diversity, community structure and abundance between three groups of lakes (fishless, native trout, nonnative trout) in the Canadian Rocky Mountains. While richness and diversity were preserved across all lake groups, other lines of evidence suggested that the introduction of native westslope cutthroat trout into fishless lakes can alter littoral benthic invertebrate communities in similar ways as nonnative brook trout (Salvelinus fontinalis). The community structure of cutthroat trout lakes resembled brook trout lakes compared to that of fishless lakes. For example, both trout-lake groups contained a lower density of free-swimming ameletid mayflies and a higher density of certain burrowing taxa. Risk assessments for trout-recovery actions should consider the potential for collateral damage to recipient invertebrate communities. Future research should identify possible cascading trophic effects on species subsidized by invertebrate prey.  相似文献   

13.
This study investigates the patterns of genetic diversity detected in allozymes, mtDNA, and microsatellites, in order to assess their relative efficacy to differentiate sympatric landlocked salmon populations and to estimate changes in genetic diversity between wild and first-generation hatchery fish. Overall, the three genetic markers indicated a genetic differentiation between two sympatric populations of Lake Saint-Jean, Québec. MtDNA and microsatellites also showed significant differences between wild and first-generation hatchery fish originating from the same river. Allozyme analysis was the most limited approach due to the low genetic diversity detected and the necessity to kill specimens. Although low polymorphism was found in mtDNA, it was the most discriminant marker between wild populations. Microsatellite analysis appears to be a promising approach due to its high sensitivity in differentiating wild populations, in detecting changes in allele composition between wild and first-generation hatchery fish and its potential for increased resolution by augmenting the number of polymorphic loci. Given the benefits and disadvantages of the three methods, the combination of mtDNA and microsatellite analyses will best address our research objectives.  相似文献   

14.
1. The extensive British canal system potentially provides a favourable habitat for aquatic plants and, because of its uniformity, it is ideal for studying relationships between disturbance intensity (largely from boat traffic) and communities of aquatic macrophytes. 2. The standing crop and species composition of aquatic plants were measured in summer at 396 sites distributed randomly over the canal network. We also quantified the number of rare species and ‘attribute groups’ (groups of species sharing similar suites of biological traits). These data were analysed in relation to standing crop, assumed to indicate a disturbance gradient. 3. Consistent with unimodal models and the Intermediate Disturbance Hypothesis, maximum hydrophyte species richness occurred at an intermediate biomass (50–200 g DWm?2). This corresponded to a low frequency of low magnitude disturbance (light boat traffic) on navigable sections, or occasional high magnitude disturbance (the post‐interventionist phase) on sections currently unnavigable and subject to active vegetation management. The frequency of rare species was also the greatest under these conditions, reflecting the availability of regeneration niches. 4. Sorting of species into attribute groups revealed that the overall relationship between species richness and standing crop comprised of closely overlapping unimodal responses of nine attribute groups, superimposed on a core vegetation of Potamogeton pectinatus, together with greater representation of filamentous algae, lemnids and elodeids with increasing standing crop (i.e. assumed low disturbance). High species richness was associated with the overlap of functionally different groups of species, rather than with disturbance‐mediated coexistence of functionally similar plants. 5. The analysis of a matrix of sites and the representation of plant traits weighted by the biomass of species that displayed them, in relation to different aspects of disturbance, highlighted a shift from traits associated with resilience (turions, unanchored floating or submerged leaves, low body flexibility, budding, small body size), or competitiveness (entire leaves, low reproductive output, high biomass density, large body size) at high standing crop, through to attributes more associated with resistance to disturbance (rhizomes, tubers, streamlining of foliage, low biomass density) at low standing crop. 6. Comparison with a stochastic null model of change in species number along a constrained gradient, after correction for variation in sampling effort, indicated that sites towards the tails of the gradient (excluding those with extremely low biomass) supported more species than might be expected from chance alone, while the most species‐rich sites in mid‐gradient generally supported many fewer species than expected. 7. We suggest that a disturbance regime that maintains intermediate standing crops would be appropriate for the conservation of species‐rich aquatic vegetation. Precise definition of this regime, under a range of circumstances, requires the study of temporal change at representative sites.  相似文献   

15.
    
For the last 30 years, cooperative management of irreplaceable animal populations in zoos and aquariums has focused primarily on the goal of minimizing genetic decay within defined time frames, and large advances have been made in technologies to optimize genetic management of closed populations. However, recent analyses have shown that most zoo programs are not projected to meet their stated goals. This has been described as a lack of achieving “sustainability” of the populations, yet by definition a goal of managed decay is not a plan for sustainability. True sustainability requires management of the resource in manner that does not deplete its value for the future. Achieving such sustainability for many managed populations may require changing from managing isolated populations to managing populations that are part of a broader metapopulation, with carefully considered exchange between populations across a spectrum of ex situ to in situ. Managing zoo populations as components of comprehensive conservation strategies for the species will require research on determinants of various kinds of genetic, physiological, behavioral, and morphological variation and their roles in population viability, development of an array of management techniques and tools, training of population managers in metapopulation management and integrated conservation planning, and projections of impacts of management strategies on the viability of the captive populations and all populations that are interactively managed or affected. Such a shift in goals and methods would result in zoo population management being an ongoing part of species conservation rather than short‐term or isolated from species conservation. Zoo Biol. 32:19‐26, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   

16.
    
While Atlantic salmon (Salmo salar) of the northernmost American populations is alimentary, economically, and culturally important for Ungava Inuit communities (Nunavik, Canada) and might play a key role in the persistence of the species in a global warming context, many mysteries remain about those remote and atypical populations. Thus, our first aim was to document the genomic structure of the Nunavik populations. The second objective was to determine whether salmon only migrating to the estuary without reaching the sea, apparently unique to those populations, represent distinct populations from the typical anadromous salmons and subsequently explore the genetic basis of migratory life-history tactics in the species. Finally, the third goal was to quantify the contribution of each genetically distinct population and life-history tactic in the mixed-stock subsistence fishery of the Koksoak R. estuary. We used Genotyping-by-Sequencing to genotype 14,061 single nucleotide polymorphisms in the genome of 248 individuals from 8 source populations and 280 individuals from the Koksoak estuary mixed-stock fishery. Life-history tactics were identified by a visual assessment of scales. Results show a hierarchical structure mainly influenced by isolation-by-distance with 7 populations out of the 8 studied rivers. While no obvious structure was detected between marine and estuarine salmon within the population, we have identified genomic regions putatively associated with those migration tactics. Finally, all salmon captured in the Koksoak estuary originated from the Koksoak drainage and mostly from 2 tributaries, but no inter-annual variation in the contribution of these tributaries was found. Our results indicate, however, that both marine and estuarine salmon contribute substantially to estuarine fisheries and that there is inter-annual variation in this contribution. These findings provide crucial information for the conservation of salmon populations in a rapidly changing ecosystem, as well as for fishery management to improve the food security of Inuit communities.  相似文献   

17.
    
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18.
渔业是大农业的一环。在充分合理的利用好水体自然资源,大力发展水产品生产的同时,认真保护好水域生态环境,这不仅是渔业的问题,也完全符合环保这项基本国策。研究渔业生态,发展生态渔业也是当今水产养殖发展的主要方向。“水体生态农业”是依据生态学原理,生态  相似文献   

19.
    
To effectively protect at‐risk sharks, resource managers and conservation practitioners must have a good understanding of how fisheries removals contribute to changes in abundance and how regulatory restrictions may impact a population trajectory. This means they need to know the number of animals being removed from a population and whether a given number of removals will lead to population increases or declines. For white shark (Carcharodon carcharias), theoretical quantities like the intrinsic rate of population increase or rebound potential (ability to increase in size following decline) are difficult to conceptualize in terms of real‐world abundance changes, which limits our ability to answer practical management questions. To address this shortfall, we designed a simulation model to evaluate how our understanding of longevity and life history variability of white shark affects our understanding of population trends in the Northwest Atlantic. Then, we quantified the magnitude of removals that could have caused historical population declines, compared these to biologically based reference points, and explored the removal scenarios which would result in population increase. Our results suggest that removals on the order of 100s of juveniles per year could have resulted in population‐level declines in excess of 60% during the 1970s and 1980s. Conservation actions implemented since the 1990s would have needed to be nearly 100% effective at preventing fishing mortality in order for the population to double in abundance over the last 30 years. Total removals from all fleets needed to be exceptionally small to keep them below biological reference points for white shark in the Northwest Atlantic. The population's inherent vulnerability to fishing pressure reaffirms the need for restrictive national and international conservation measures, even under a situation of abundance increase.  相似文献   

20.
    
Census (N(C)) and effective population size (N(e)) were estimated for a lake-resident population of brown trout Salmo trutta as 576 and 63, respectively. The point estimate of the ratio of effective to census population size (N(e):N(C)) for this population is 0.11 with a range of 0.06-0.26, suggesting that N(e):N(C) ratio for lake-resident populations agree more with estimates for fishes with anadromous life histories than the small ratios observed in many marine fishes.  相似文献   

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