共查询到20条相似文献,搜索用时 15 毫秒
1.
Since 1986, when green oysters occurred due to the copper and organic pollution in the Charting coastal area, the government banned all maricultural activity. It has been claimed that growing algae in a polluted environment may clean the water of pollutants and restore the marine ecosystem. to test this hypothesis, in the Charting coastal area a three-year programme (from August 1992 to July 1995) was carried out. the survey programme included environmental components such as salinity, temperature, pH, dissolved oxygen, biological oxygen demand (BOD), particulate organic carbon (POC), heavy metals and ecological indicators such as nutrients, chlorophyll-a, primary productivity. in the first year study, the environmental background data collected was used to select the suitable season and locations for growing large algae transferred from the laboratory to the field study area. Since September 1993, various species of large algae have been cultured. Although some of the growing algae were damaged by a typhoon in August 1994, the impact of the growing algae on the environmental conditions in the area has been monitored throughout. Elsewhere, we have reported that in the algae growing area higher dissolved oxygen with lower values of BOD and POC were found, and the concentrations of heavy metals in both water and sediments decreased. the purpose of this paper is to evaluate the possible impact of growing large algae on the ecological conditions in Charting coastal waters through the period from August 1983 to May 1995. As a result of the positive results obtained, large amounts of algae have again been cultured in the same area during the period from April 29 to May 25, 1995. We expect that inorganic and organic pollutants will be reduced by the algal growth, oyster mariculture will be restored and finally, the fishery resources potential will be increased. 相似文献
2.
D. V. Quayle 《Chemistry and Ecology》1992,6(1):69-78
Plastics debris is known to be present in all of the world's oceans, and on most amenity beaches, although comparatively little data are available to provide reliable information on the extent of damage from this pollution, and on its spatial and temporal variations.
Marine pollution by plastics has been shown to be damaging to marine mammals, birds and reptiles. This is due to entanglement in packaging bands, synthetic ropes and lines, or drift nets; or by the ingestion of small items of plastics debris. More research is needed to quantify the extent of the problems.
Wider use of degradable plastics will not solve the problems of plastics pollution. Their lifetimes are relatively long and unpredictable, and they are not generally acceptable for recycling.
Marine plastics pollution may be alleviated by the judicious application of both economic incentives and legislation, designed to decrease their use, to increase the rate of recycling, and to restrict uncontrolled discards. 相似文献
Marine pollution by plastics has been shown to be damaging to marine mammals, birds and reptiles. This is due to entanglement in packaging bands, synthetic ropes and lines, or drift nets; or by the ingestion of small items of plastics debris. More research is needed to quantify the extent of the problems.
Wider use of degradable plastics will not solve the problems of plastics pollution. Their lifetimes are relatively long and unpredictable, and they are not generally acceptable for recycling.
Marine plastics pollution may be alleviated by the judicious application of both economic incentives and legislation, designed to decrease their use, to increase the rate of recycling, and to restrict uncontrolled discards. 相似文献
3.
D. V. Quayle 《Chemistry and Ecology》2013,29(1-4):69-78
Plastics debris is known to be present in all of the world's oceans, and on most amenity beaches, although comparatively little data are available to provide reliable information on the extent of damage from this pollution, and on its spatial and temporal variations. Marine pollution by plastics has been shown to be damaging to marine mammals, birds and reptiles. This is due to entanglement in packaging bands, synthetic ropes and lines, or drift nets; or by the ingestion of small items of plastics debris. More research is needed to quantify the extent of the problems. Wider use of degradable plastics will not solve the problems of plastics pollution. Their lifetimes are relatively long and unpredictable, and they are not generally acceptable for recycling. Marine plastics pollution may be alleviated by the judicious application of both economic incentives and legislation, designed to decrease their use, to increase the rate of recycling, and to restrict uncontrolled discards. 相似文献
4.
珠江口叶绿素a时空分布及初级生产力 总被引:2,自引:0,他引:2
2006年5月至2008年2月季度性对珠江口叶绿素a的时空分布特征及其与环境因子的关系以及珠江口水域初级生产力等进行研究。结果表明,表层叶绿素a含量分别与底层、上游叶绿素a含量间无显著差异;表层叶绿素a含量在夏、春季明显大于秋、冬季,但各口门间无显著差异。珠江口水域初级生产力水平夏、秋季明显高于春、冬季,但各口门间无显著差异。表层叶绿素a含量分别与浮游植物细胞密度、初级生产力间相关显著。不同口门及不同季节间影响叶绿素a含量的环境因子存在较大差异。 相似文献
5.
湘乡市16年生不同密度的马尾松(Pinus massoniana)飞播林林分单株生物量随密度的增加而明显减小,低密度林分是高密度林分的2 42倍,高出18.33kg;当林分密度一定后,林分生物量同样随密度的增加而减小,低密度林分比高密度林分高出21.81t/hm2。林分各组生物量随密度增大而减小,并出现W>W根>W枝>W皮>W叶的规律。年均净生长量低密度林分是高密度林分的1.40倍。 相似文献
6.
K. J. Flynn 《Chemistry and Ecology》1989,4(1):21-36
Nutrient limitation of phytoplankton growth in nature is a complex phenomenon. the timing of nutrient limitation is a product of matching of algal growth with abiotic and/or biotic events regenerating nutrients, and mismatching with predator activity. the extent of production is governed by the concentration of atomic constituents which, in turn, is a function of the rapidity and quantity of nutrient regeneration by heterotrophs. Excess phytoplankton production over heterotroph demand is lost from the euphotic zone by sinking and from the ecosphere by sedimentation. Phytoplankton growth is therefore always limited by the size and activity of the regenerative food web, either directly through predation, or indirectly by inadequate nutrient regeneration. the open water column is a habitat deplete environment for metazoa, incapable of supporting simultaneous high predator and prey densities. Because of the incompatibility of the temporal and spatial scales of microbial and metazoan processes, and the presence of micro-habitats which can support a full recycling food web on microbial scales, the microbial loop is an important component of euphotic zone ecology. the total marine ecosystem runs at a nutrient sufficient level with nutrient deplete and replete phases dependent on matching of production with predation throughout the food web and subject to abiotic events. Man's release of N and P into coastal waters, if coupled with an increased incidence of mismatch resulting from climatic variation induced by the “greenhouse effect”, could have catastrophic effects on marine ecosystems. 相似文献
7.
8.
Species Extinction in the Marine Environment: Tasmania as a Regional Example of Overlooked Losses in Biodiversity 总被引:2,自引:0,他引:2
Abstract: We used Tasmania as a case example to question the consensus that few marine species have recently become extinct or are approaching extinction. Threats to marine and estuarine species—primarily in the form of climate change, invasive species, fishing, and catchment discharges—are accelerating, fully encompass species ranges, and are of sufficient magnitude to cause extinction. Our ignorance of declining biodiversity in the marine environment largely results from an almost complete lack of systematic broad-scale sampling and an overreliance on physicochemical data to monitor environmental trends. Population declines for marine species approaching extinction will generally go unnoticed because of the hidden nature of their environment and lack of quantitative data. 相似文献
9.
Abstract: New Zealand established its first no-take marine reserve more than 25 years ago. Twenty no-take marine reserves have now been created, although few of these are considered comparable. We considered whether existing conceptual models of population and community structure based only on data from exploited systems lack the baseline information of natural states necessary to make accurate predictions for new reserves. Three of the oldest and best-studied reserves are situated on the northeastern coast of New Zealand. These reserves are considered broadly comparable replicates, and research has shown the recovery of previously exploited predator populations and the reestablishment of trophic controls over community structure and productivity. None of the major changes was predicted when the reserves were created. All the observations from and experimental tests of hypotheses in these three ecologically comparable reserves have provided predictive models for future reserves. Recent surveys in newly created reserves, however, suggest that these models are bioregion and habitat specific. In these new reserves the recovery of previously exploited predators was predicted but did not always occur. Where trends were correctly predicted, the speed and amplitude of the changes were not accurately predicted. Research in New Zealand suggests that it is not yet possible to predict explicit outcomes for newly created reserves and less possible to predict detailed results for systems of reserves. Results from a representative system of reserves, including all major habitats within all bioregions and broadly comparable reserves, are needed. Such a system will enable the range and variety of natural ecosystem dynamics to be investigated and provide the controls necessary to measure the effects of exploitation. 相似文献
10.
为了揭示出海洋纤毛虫在人工海水中及不同温度下的种群动力学,利用实验生态学方法,就4种培养液及2种(17℃和23℃)温度对海洋纤毛虫扇形游仆虫(Euplotes vannus Mailer,1786)种群增长的影响进行了初步探讨.结果显示:①该种纤毛虫原生动物在4种人工海水培养液中的种群增长率大小顺序为:牛肉浸膏培养液〉米粒培养液〉酵母粉培养液〉蛋白胨培养液;②种群密度大小顺序依次为:米粒培养液〉牛肉浸膏培养液〉酵母粉培养液〉蛋白胨培养液;③指数增长期及稳定期在米粒培养液中均长于牛肉浸膏培养液;④随着培养温度的升高,种群增长率增大,指数增长期及稳定期缩短;⑤温度系数(Q10)的大小顺序为:蛋白胨培养液〉牛肉浸膏培养液〉米粒培养液〉酵母粉培养液.结果表明,米粒人工海水培养液不仅适合于保种培养,而且适合于种群的扩大培养,而牛肉浸膏培养液更适合于种群的快速扩大培养,其他两种培养液则只适合于保种培养.图2表4参13 相似文献
11.
为了揭示出海洋纤毛虫在人工海水中及不同温度下的种群动力学,利用实验生态学方法,就4种培养液及2种(17℃和23℃)温度对海洋纤毛虫扇形游仆虫(Euplotesvannus Müller,1786)种群增长的影响进行了初步探讨.结果显示①该种纤毛虫原生动物在4种人工海水培养液中的种群增长率大小顺序为牛肉浸膏培养液>米粒培养液>酵母粉培养液>蛋白胨培养液;②种群密度大小顺序依次为米粒培养液>牛肉浸膏培养液>酵母粉培养液>蛋白胨培养液;③指数增长期及稳定期在米粒培养液中均长于牛肉浸膏培养液;④随着培养温度的升高,种群增长率增大,指数增长期及稳定期缩短;⑤温度系数(Q10)的大小顺序为蛋白胨培养液>牛肉浸膏培养液>米粒培养液>酵母粉培养液.结果表明,米粒人工海水培养液不仅适合于保种培养,而且适合于种群的扩大培养,而牛肉浸膏培养液更适合于种群的快速扩大培养,其他两种培养液则只适合于保种培养.图2表4参13 相似文献
12.
漓江流域红壤区生态恢复过程中植被结构动态和生物量变化 总被引:3,自引:0,他引:3
利用时空替代原理,选取漓江流域红壤区退化生态系统恢复过程中具有代表性的草丛、灌丛、针叶林、针阔混交林、常绿阔叶林5个阶段作为演替序列,研究自然恢复过程中各演替阶段的植被结构动态和生物量变化。结果表明:随着草丛→灌丛→针叶林→针阔混交林→次生常绿阔叶林正向演替的进行,在未形成成熟而稳定的顶极群落之前,物种丰富度、物种多样性指数、植被生物量及生产力都呈增大趋势。退化群落通过自然恢复总是向着结构更复杂、更完善的方向发展。根据恢复过程中植被的动态变化规律,提出了一些人工促进植被恢复的建议. 相似文献
13.
T. M. COX§ R. L. LEWISON† R. YDELIS L. B. CROWDER C. SAFINA‡ A. J. READ 《Conservation biology》2007,21(5):1155-1164
Abstract: Fishers, scientists, and resource managers have made substantial progress in reducing bycatch of sea turtles, seabirds, and marine mammals through physical modifications to fishing gear. Many bycatch-avoidance measures have been developed and tested successfully in controlled experiments, which have led to regulated implementation of modified or new fishing gear. Nevertheless, successful bycatch experiments may not translate to effective mitigation in commercial fisheries because experimental conditions are relaxed in commercial fishing operations. Such a difference between experimental results and real-world results with fishing fleets may have serious consequences for management and conservation of protected species taken as bycatch. We evaluated preimplementation experimental measures and postimplementation efficacy from primary and gray literature for three case studies: acoustic pingers that warn marine mammals of the presence of gill nets, turtle excluder devices that reduce bycatch of turtles in trawls, and various measures to reduce seabird bycatch in longlines. Three common themes to successful implementation of bycatch reduction measures are long-standing collaborations among the fishing industry, scientists, and resource managers; pre- and postimplementation monitoring; and compliance via enforcement and incentives. 相似文献
14.
Environmentally Sensitive Productivity Analysis of the Canadian Pulp and Paper Industry, 1959-1994: An Input Distance Function Approach 总被引:8,自引:0,他引:8
This study employs a parametric input distance function that incorporates both desirable and undesirable outputs to provide a more complete representation of the production technology from which environmentally sensitive productivity and efficiency measures can be generated. This framework also generates pollution abatement cost estimates that are useful for policy making. An input-based Malmquist index of productivity growth that appropriately credits the producer not only for increases in marketable or desirable outputs but also for the production of improved environmental quality through pollution abatement activities is derived from the input distance function. The method was applied to time series data from the Canadian pulp and paper industry. Our shadow price estimates indicate that the marginal cost to producers of pollution control has been rising. The main conclusion of this study is that productivity improvement, from the social viewpoint, has been stronger than conventional measures would suggest. 相似文献
15.
铯-137(~(137)Cs)是滨海核电站液态流出物中主要人工放射性核素和重要监控指标之一,易被水生生物累积,有关核电周边海域内海洋生物的核素富集状况备受关注。通过分析海洋生物富集放射性~(137)Cs的方式、生物富集系数的种群特征、人工放射性核素在生物体内的辐射剂量率状况,结果显示:1)滨海核电周边海域内~(137)Cs的放射性水平较低; 2)海洋生物对于~(137)Cs的富集未呈现显著的种群规律; 3)目前对放射性铯的富集能力较高的生物主要是底栖生物; 4)核电厂周边海域内海洋生物通常未达到可导致电离辐射损伤的辐射剂量率水平。随着滨海核电在我国的大力发展,对能够快速反映环境放射性状况的指示生物的筛选、生物放射性质量安全及其生态健康风险需进一步关注。 相似文献
16.
Beyond Biogeography: a Framework for Involving the Public in Planning of U.S. Marine Protected Areas 总被引:2,自引:0,他引:2
TRACEY MORIN DALTON 《Conservation biology》2005,19(5):1392-1401
Abstract: Planning of marine protected areas (MPAs) is highlighted in the conservation literature but is not explored in much detail. Many researchers acknowledge the importance of involving the public in MPA planning, but there is limited guidance on how to do this in an effective manner. I present a framework for involving the public in planning of U.S. MPAs. Derived from empirically and theoretically based research on public participation in U.S. natural resource management, this framework is composed of factors that influence the success of participatory processes: active participant involvement, complete information exchange, fair decision making, efficient administration, and positive participant interactions. Processes incorporating these factors will produce decisions that are more likely to be supported by stakeholders, meet management objectives, and fulfill conservation goals. This framework contributes to the MPA social science literature and responds to calls in the conservation literature to increase the use of social science research to inform conservation decision making. 相似文献
17.
邻苯二甲酸酯的环境污染和生态行为及毒理效应研究进展 总被引:3,自引:0,他引:3
邻苯二甲酸酯作为产品改性剂被广泛应用于食品包装、建筑板材、医疗器械等产品中,由于PAEs与塑料分子难以形成强力的共价结合,造成其不断泄露至脂溶性环境中,在基质接触和食物网传递作用下,PAEs被各种生物体蓄积并表现出一定的内分泌干扰效应。文章以PAEs的物化性质及其在大气、水体、土壤中的污染现状为研究基础,介绍了PAEs的生物体蓄积水平与代谢路径,并分别从水解、光解及生物降解3个角度展示了PAEs的环境降解过程与机理;此外,结合实验室报道及社会调查,深入探讨了PAEs的环境激素效应,"致癌、致畸、致突变"效应,酶与激素毒性;最后,基于当前PAEs在毒理分析、降解途径及环境暴露统计研究上的不足,指出需进一步进行复杂食物链毒性积累与放大研究,发展PAEs的生物治理与削减技术以及进行PAEs环境暴露水平调查,确定全面合理的环境标准限值。 相似文献
18.
Abstract: Ecological restoration is a key component of biological conservation. Nevertheless, unlike protection of existing areas, restoration changes existing land use and can therefore be more controversial. Some restoration projects negatively affect surrounding landowners, creating social constraints to restoration success. Just as negative off‐site impacts (i.e., negative externalities) flow from industrial areas to natural areas, restoration projects can generate negative externalities for commercial land uses, such as agriculture. Negative externalities from industry have led to government regulation to prevent human health and environmental impacts. Negative externalities from restoration projects have elicited similar legal constraint on at least one large‐scale conservation project, riparian restoration in the Sacramento River Conservation Area. The negative externalities of restoration that are perceived to be the direct result of specific goals, such as endangered species management, are likely to be more contentious than externalities arising from unintended phenomena such as weed invasion. Restoration planners should give equal consideration to off‐site characteristics as to on‐site characteristics when choosing sites for restoration and designing projects. Efforts to control externalities can lead to off‐site ecological benefits. 相似文献
19.
Abstract: Over the last decade, 2 major U.S. commissions on ocean policy and a wide range of independent sources have argued that ocean ecosystems are in a period of crisis and that current policies are inadequate to prevent further ecological damage. These sources have advocated ecosystem-based management as an approach to address conservation issues in the oceans, but managers remain uncertain as to how to implement ecosystem-based approaches in the real world. We argue that the philosophies of Edward F. Ricketts, a mid-20th-century marine ecologist, offer a framework and clear guidance for taking an ecosystem approach to marine conservation. Ricketts' philosophies, which were grounded in basic observations of natural history, espoused building a holistic picture of the natural world, including the influence of humans, through repeated observation. This approach, when applied to conservation, grounds management in what is observable in nature, encourages early action in the face of uncertainty, and supports an adaptive approach to management as new information becomes available. Ricketts' philosophy of "breaking through," which focuses on getting beyond crisis and conflict through honest debate of different parties' needs (rather than forcing compromise of differing positions), emphasizes the social dimension of natural resource management. New observational technologies, long-term ecological data sets, and especially advances in the social sciences made available since Ricketts' time greatly enhance the utility of Ricketts' philosophy of marine conservation. 相似文献
20.
Christian Damgaard 《Environmental and Ecological Statistics》2006,13(2):229-236
A methodology for estimating environmental thresholds of binary presence–absence data is presented where the level of the
threshold is parameterised. Presence–absence data is fitted to three complementary different models: an independent null-model,
a monotonically increasing or decreasing model, and an optimum model. The range of the three models is strictly between zero
and one and the models are therefore well suited for modelling presence probabilities. The results of the three models may
be combined by using Bayesian model selection methodologies. The proposed methodology is exemplified on observed binary presence–absence
data of Bauera rubioides along an elevation gradient.
Received: May 2005 / Revised: July 2005
An erratum to this article is available at. 相似文献