共查询到20条相似文献，搜索用时 31 毫秒
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Eric D. H. Durieux Thomas B. Farver Patrick S. Fitzgerald Kai J. Eder David J. Ostrach 《Fish physiology and biochemistry》2011,37(1):21-29
Acetylcholinesterase (AChE) activity is one of the most common biomarkers of neurotoxicity used in aquatic organisms. However,
compared to its extensive use as biomarker, the effects of natural factors on AChE activity remain unclear especially in estuarine
fishes. The aim of this study was to evaluate the effects of natural factors on AChE activity of striped bass (Morone saxatilis) juveniles. Brain AChE activity was measured in YOY (Young-Of-Year) individuals collected monthly from August 2007 to January
2008 at 12 different sites in the San Francisco Estuary system. The spatio-temporal variability of AChE was analyzed relative
to water temperature and salinity as well as fish size. AChE activity was highly positively correlated with water temperature
and to a lesser extent negatively with fish size while no relationship was detected with salinity. Taking into account these
natural factors when using AChE as a biomarker will help to determine and understand the effects of neurotoxic contaminants
on fish in estuarine systems. 相似文献
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Emilie Laurin Krishna Thakur Peter G. Mohr Paul Hick Mark St. J. Crane Ian A. Gardner Nicholas J. G. Moody Axel Colling Ingo Ernst 《Journal of fish diseases》2019,42(11):1471-1491
Samples from multiple animals may be pooled and tested to reduce costs of surveillance for infectious agents in aquatic animal populations. The primary advantage of pooling is increased population‐level coverage when prevalence is low (<10%) and the number of tests is fixed, because of increased likelihood of including target analyte from at least one infected animal in a tested pool. Important questions and a priori design considerations need to be addressed. Unfortunately, pooling recommendations in disease‐specific chapters of the 2018 OIE Aquatic Manual are incomplete and, except for amphibian chytrid fungus, are not supported by peer‐reviewed research. A systematic review identified only 12 peer‐reviewed aquatic diagnostic accuracy and surveillance studies using pooled samples. No clear patterns for pooling methods and characteristics were evident across reviewed studies, although most authors agreed there is a negative effect on detection. Therefore, our purpose was to review pooling procedures used in published aquatic infectious disease research, present evidence‐based guidelines, and provide simulated data examples for white spot syndrome virus in shrimp. A decision tree of pooling guidelines was developed for use by peer‐reviewed journals and research institutions for the design, statistical analysis and reporting of comparative accuracy studies of individual and pooled tests for surveillance purposes. 相似文献
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M. Oliva J. J. Vicente-Martorell M. D. Galindo-Riaño J. A. Perales 《Fish physiology and biochemistry》2013,39(3):523-545
As a component of a large research project to evaluate the effects of contaminants on fish health in the field, histopathological studies have been conducted to help establish causal relationship between pollutants (heavy metals and aromatic polycyclic hydrocarbons—PAHs) and histopathological responses in Senegal sole, Solea senegalensis, from an estuary of SW Spain. Heavy metals (As, Zn, Cd, Pb, Cu and Fe) and 16 PAHs (proprietary USEPA) concentrations in water, sediment and tissues (liver and gills) and histopathological alterations in S. senegalensis from three sampling sites of Ria de Huelva estuary during 2004–2006 years have been analysed. The histopathological studies revealed seasonal and spatial differences in the lesion grade of alterations observing the highest lesion grades in fish from Odiel River and autumn season. No significant differences were observed in the alterations prevalence between sampling sites, but significant differences were observed between seasons observing the highest prevalence in autumn season. However, calculated IPAT demonstrated a low–moderate impact of pollutants on health fish. Correlations between histopathological alterations and pollutants analysed were observed being heavy metals the group that presented a major number of correlations with alterations in several organs of S. senegalensis. In evaluating the general health of fish, the use of histopathological studies in recommended for making more reliable assessment of biochemical responses in fish exposed to a variety of environmental stressors. Statistical analysis using semiquantitative data on pathological lesions can help to establish correlation between cause (stressor) and effect (biomarker). 相似文献
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为研究三江并流区澜沧江干流水、陆生境中的捕食线虫真菌（Nematode-Trapping Fungi,NTF）多样性分布差异,在该区域布设9个采样区对NTF进行调查,并分析NTF在澜沧江流域不同空间尺度下的水陆分布模式。每个样区设置水、陆对称采样点各5个,每个采样点用5点法采集水、陆样品各1份,共采集90份样品。采用单孢子挑离法获得NTF纯培养,结合形态学和分子生物学方法鉴定物种。共获得2属13种76株NTF,其中陆生土壤中检出2属11种49株,水体底泥中检出1属6种27株。结果显示,NTF物种组成在三江并流区澜沧江干流水、陆生境间存在较大差异,具有水陆异质性分布模式,干流陆地上具有比水生环境中更高的物种检出率和物种多样性;此外,与之前对澜沧江支流NTF的水陆分布研究结果相比,NTF在干流上水陆分布差异比支流更大,表明在流域生态系统中,NTF的监测结果同时也能反映不同空间尺度下的环境异质性,以流域为研究单元,以NTF为研究对象,可能更有助于了解微生物的空间分布格局。 相似文献
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水生生物在食物网中的相互关系及其变化是生态学研究的重要领域之一,其实质是研究生物之间的捕食与被捕食关系。传统的水生食物网研究方法是基于形态学观察的胃含物分析,具有较大的局限性。随着科学技术的发展,稳定同位素技术、特征脂肪酸组成分析和DNA条形码等分子技术的引入有效的弥补了胃含物分析的不足,并可以更深入的了解水生生物的摄食信息,因此得到了广泛的应用。本文采用文献计量法分析了水生食物网研究方法的发展动态,分别介绍了稳定同位素技术、特征脂肪酸组成分析和DNA条形码技术与胃含物结合应用的研究进展,着重归纳总结了其在水生生物食性研究中的应用现状及发展前景,详细地指出了4种水生食物网研究方法的优势和局限性、适用范畴和对实验样品的需求。胃含物分析作为传统食物网研究方法未来仍是不可缺少的一部分,其向我们传递了最为直接的摄食信息。在此基础上,稳定同位素技术、特征脂肪酸组成分析和DNA条形码等分子技术作为胃含物分析方法的补充手段,将更有利于重建复杂的水生食物网结构,进而为渔业管理提供必要的帮助。 相似文献
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Piotr Parasiewicz Elise L. King J. Angus Webb Miko&#x;aj Piniewski Claudio Comoglio Christian Wolter Anthonie D. Buijse David Bjerklie Paolo Vezza Andreas Melcher Katarzyna Suska 《Fisheries Management and Ecology》2019,26(6):461-473
Floods and droughts are key driving forces shaping aquatic ecosystems. Climate change may alter key attributes of these events and consequently health and distribution of aquatic species. Improved knowledge of biological responses to different types of floods and droughts in rivers should allow the better prediction of the ecological consequences of climate change‐induced flow alterations. This review highlights that in unmodified ecosystems, the intensity and direction of biological impacts of floods and droughts vary, but the overall consequence is an increase in biological diversity and ecosystem health. To predict the impact of climate change, metrics that allow the quantitative linking of physical disturbance attributes to the directions and intensities of biological impacts are needed. The link between habitat change and the character of biological response is provided by the frequency of occurrence of the river wave characteristic—that is the event's predictability. The severity of impacts of floods is largely related to the river wave amplitude (flood magnitude), while the impact of droughts is related to river wavelength (drought duration). 相似文献
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- 1. The fauna of inland waters has the highest rates of imperilment of any ecosystems as a result of human demands and catchment manipulations. Thus, the conservation of these systems requires multi‐disciplinary and international collaboration.
- 2. In order to examine patterns of change in collaborative research we examined eight of the leading limnological journals over a 10 yr period, with another two journals examined over 5 yr.
- 3. Of the 9758 surveyed papers, single‐authored papers were proportionally the second most commonly published (N=2523: 25.86%) while dual‐authored papers accounted for the greatest number of papers (N=3517: 36.04%). There was a significant increase in collaboration and a decline in the relative proportion of single‐ (r2=0.71; P=0.00) and dual‐authored (r2=0.54; P=0.00) papers.
- 4. Collaboration between authors from different countries was recorded for 827 of the 8636 (9.58%) papers examined. While there was an annual average of 864 (8.57%) papers involving international collaboration, the range varied from 464 (5.60%: 1990) to 1374 (12.66%: 1995). There was a significant increase (r2=0.59; P=0.01) in the number of papers involving international collaboration.
- 5. ‘Third World’ contributions constituted an average of 7.64% of papers published annually, ranging from 5.32% of all papers in 1987 to 9.31% in 1994.
- 6. Roughly equal proportions of lentic, lotic and marine papers were published over the survey period. Taxonomic and estuarine research was poorly represented probably due to the many specialist journals available for such publications. The data do not support the assertion that there has been an increase in lotic research at the expense of lentic research. Indeed, our data show a significant decrease in the number of papers published relating to lotic systems (r2=0.51; P=0.02).
- 7. The future of collaborative research conducted by multi‐institutional and multi‐disciplinary teams and its significance in terms of the management and conservation of aquatic ecosystems globally is discussed.
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《Journal Of Applied Aquaculture》2013,25(3-4):283-316
ABSTRACT India is a very populous country with more than one billion people. In order to provide food for this growing population, serious environmental problems may result. Despite many benefits from the green, blue, and silver revolutions adopted in India, there has been much concern resulting from intensive agricultural practices that led to environmental problems in both terrestrial and aquatic ecosystems. Increasing demand for aquatic resources also caused inland fisheries to decrease over the past few decades. The location of aquaculture projects, landscape destruction, soil and water pollution by pond effluents, over-exploitation of important fish stocks, depletion in biodiversity, conflicts over agriculture and aquaculture among various stakeholder groups over resource and space allocation, and international fish trade controversies have threatened the long-term sustainability of fisheries and aquaculture industries. The subject of sustainable aquaculture has not been adequately projected in terms of current aquaculture practices aimed to boost a rural economy. This review briefly describes the key issues of aquaculture unsustainability in terms of intensive aquaculture, nutrient enrichment syndrome, soil and groundwater salinization, destruction of mangroves, loss of biodiversity, marine pollution and loss of fish stock, use of aquachemicals and therapeutics, hormone residues, etc. The strategies for sustainability have been highlighted with respect to rice-cum-fish culture, carp polyculture, integrated farming with livestock, rural aquaculture, intensification of small farms, wastewater-fed aquaculture, crop rotation, probiotics, feed quality, socioeconomic considerations, environmental regulations and fisheries acts, transboundary aquatic ecosystems, impact of alien species, ethical aspects of intensive aquaculture, responsible fisheries, and environmental impact assessment. A suggested model outlines the feedback mechanisms for achieving long-term sustainability through improved farm management practices, integrated farming, use of selective aquachemicals and probiotics, conservation of natural resources, regulatory mechanism, and policy instruments. 相似文献
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Johannes Radinger J. Robert Britton Stephanie M. Carlson Anne E. Magurran Juan Diego Alcaraz‐Hernndez Ana Almodvar Lluís Benejam Carlos Fernndez‐Delgado Graciela G. Nicola Francisco J. Oliva‐Paterna Mar Torralva Emili García‐Berthou 《Fish and Fisheries》2019,20(4):729-747
Freshwater ecosystems constitute only a small fraction of the planet's water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, pollution and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g., early detection of alien species), tracking changes in the abundance of threatened species, or documenting long‐term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasize that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy and ethics in their monitoring programmes. Additionally, programmes must ensure that high‐quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems and help protect these systems in face of rapid environmental change. 相似文献
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Juliana Campos Hashimoto Jonas Augusto Rizzato Paschoal Júlio Ferraz de Queiroz 《Journal Of Aquatic Food Product Technology》2013,22(3):273-294
Aquaculture in Brazil has shown expressive development since the 1990s with growth rates superior to those of cattle and poultry. In order to achieve greater productivity, intensive fish cultivation systems are employed, which can cause greater susceptibility to diseases caused by viruses, bacteria, fungi, and parasites. The reduced availability of veterinary medications approved for use in aquaculture in Brazil has lead fish farmers to the indiscriminate use of several chemical substances with antimicrobial activity, such as the dye malachite green (MG). As a result of this use, residues of MG and its main biotransformation product, leucomalachite green (LMG), may be present in fish available for consumption. The presence of residues of these compounds represents a risk to human health due to their toxicity, as well as a potential impact on the environment, and could also raise barriers for commercialization in the country and for exportation. The objective of this review is to provide the context and evidence of the use of MG in aquaculture and of its toxicological and legislative aspects. A review of the analytical methods used to determine MG residues in fish, with emphasis on mass spectrometry, is also presented. 相似文献
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John M. Melack Daniele Kasper João H.F. Amaral Pedro M. Barbosa Bruce R. Forsberg 《水产资源保护:海洋与淡水生态系统》2021,31(12):1041-1055
- Limnological aspects of Amazon floodplain lakes are examined in the context of aquatic conservation.
- A prerequisite to detecting and evaluating changes that could threaten the ecological health and organisms in floodplain lakes is understanding variation under present conditions. Based on one of the few studies with regular measurements over 2 years, chlorophyll, total phosphorus, dissolved oxygen, transparency, and total suspended solids in Lake Janauacá indicate that the lake is naturally quite variable with a mesotrophic to eutrophic status.
- Direct threats to ecological health of floodplain lakes include mining operations that can increase turbidity and trace metals and reduce nutritional quality of sediments. Mercury contamination and methylation leads to bioaccumulation in aquatic organisms.
- Deforestation in uplands increases nitrogen and phosphorus inputs to floodplain lakes and can alter trophic status. Deforestation in floodable forests alters the habitat and food of the fish that inhabit these forests.
- Cumulative limnological responses as catchments are altered by urban, agricultural, and industrial developments, and as inundation is altered by changes in climate and construction of dams, have major implications for the ecology of floodplain lakes.
- To improve understanding and management of threats to the conservation of aquatic Amazon biota and ecosystems requires considerably expanded and coordinated research and community-based management that includes the spectrum of floodplain lakes throughout the basin.
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Kenneth Irvine Leandro Castello Andrea Junqueira Timothy Moulton 《水产资源保护:海洋与淡水生态系统》2016,26(5):917-941
1. Tropical aquatic ecosystems are species rich, with high numbers of endemics. Increasing pressure from human activities, including demands for food and energy, growing human population, and economic aspirations, highlights the need for a more concerted effort towards aquatic conservation. 2. Understanding of tropical aquatic ecosystems has developed largely from a northern temperate perspective that might not be always appropriate. Applying classic models of how water bodies function can hinder effective conservation strategies. This is coupled with very incomplete knowledge of species distributions and their ecology. 3. Better understanding of tropical aquatic ecology to guide conservation needs a research agenda that connects more strongly with the social‐ecological realities of tropical ecosystems. 4. Although approaches to conservation may be contested, a fundamental challenge to protection of aquatic habitats is a lack of capacity at the individual and institutional level. Without this, the development of improved techniques and approaches for tropical aquatic conservation will fail to reverse current trends of degradation. Research outputs on tropical aquatic ecosystems remain dominated by institutions based outside the tropics. 5. Building awareness and practice to conserve the aquatic ecosystems of the tropics can be supported through extending the dialogue across sectors and by connecting tiers of governance. An ecosystem services framework that identifies the benefits that humans derive from ecosystems provides a powerful tool, often linked with estimates of economic value. However, this can neglect important regulating services or distract from more fundamental existence value. 6. The preservation of tropical aquatic diversity will only be achieved if recognized as important at all levels, from local to global. Targeted external support can build awareness and capacity, but conserving aquatic ecosystems requires local commitment. Developing community monitoring that provides straightforward information on ecosystem health presents opportunities to connect citizens with the ecosystems that, ultimately, they depend on. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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评估北运河水系生态状况，为判别北运河水系水生态恢复成效提供参考。2020 年5月、8月调查了北运河13个采样点的鱼类及生境状况，采集到鱼类20种，分属3目9科18属。采用F-IBI评价北运河健康状况。选择人类活动干扰较轻的点作为参照点，从物种种类组成与丰富度、营养结构、耐受性和敏感性、繁殖共位群以及鱼类数量等5个方面构建F-IBI候选指标体系，然后依据分布范围检验、敏感性分析和相关性检验，筛选出F-IBI 核心指标体系，包括鱼类物种数、Shannon-Wiener 多样性指数、鲤科物种数百分比、漂流性卵鱼类个体数百分比、沉性卵鱼类个体数百分比、黏性卵鱼类个体数百分比、外来物种数量所占比例。采用比值法计算各采样点F-IBI值，并将其划分为“优”“良”“中”“一般”和“差”5个健康评价等级，评价各采样点健康状况。评价结果表明：北运河健康状况整体为中等偏上，其中7.69%的采样点健康状况为“优”，23.08% 的采样点健康状况为“良”，53.85%的采样点健康状况为“中”，15.38%的采样点健康状况为“一般”。北运河水生态治理取得一定成效。 相似文献
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The temporal dynamics of biotic communities have been widely examined by ecologists. However, systematic reviews on how habitat features, sampling and data evaluation influence temporal patterns are rather sporadic. Here, we reviewed 307 peer-reviewed scientific articles to characterize the methods and the approaches, as well as to identify the knowledge gaps in the assessment of the temporal dynamics of freshwater fish assemblages with special regard to their stability patterns. The number of publications increased exponentially over decades. We revealed a highly uneven distribution of the studies among continents and ecosystems with a dominant number of papers derived from North America and Europe, and from lotic systems, especially. We also found large variability among studies even within similar habitat types in the examined spatial and temporal scales, sampling methods used, examined assemblage attributes, potential stressors and data analyses. Several knowledge gaps, such as the limited number of large-scale studies, the insufficient knowledge on the long-term dynamics of early life history stages and on trait-based assemblage organization, were highlighted. For enabling meaningful comparisons of fish assemblage dynamics in space and time, further developments in standardization procedures are needed across sampling and data evaluation possibilities. Publicly accessible long-term data sets with more details on sampling and environmental parameters would also be critically important to determine the effect of a variety of factors on the stability vs. variability of fish assemblages. 相似文献
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为研究岩溶地下河沉水植物分布、群落组成及生境对群落结构的影响,2013年7-8月,对寨底地下河沉水植物分布及群落多样性进行了调查,并结合全年水质监测数据,分析了生境对沉水植物群落多样性分布的影响。结果表明,寨底地下河出口共有沉水植物4科、6属、8种;优势种为苦草(Vallisneria natans)、靖西海菜花(Ottelia acuminata var.jingxiensis)、竹叶眼子菜(Potamogeton wrightii)和黑藻(Hydrilla verticillata),优势度分别为33.87%、23.10%、19.06%和12.50%,其中苦草为第一优势种。河道基质是制约沉水植物多样性分布的重要因素,砂石基质处沉水植物为种类单一的海菜花群落;泥沙混合处沉水物种组成比较丰富,海菜花、黑藻、竹叶眼子菜、苦草等形成共优势群落。岩溶水高Ca2+和HCO-3环境为沉水植物光合作用提供了丰富的矿物质元素及光合作用碳源。研究结果可为寨底地下河岩溶水生生态系统中沉水植物碳汇效应提供理论支持。 相似文献
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大型底栖动物是评价水生态健康状况最常用的生物类群。为系统评价东江流域上游生态健康水平,以底栖动物为指示生物,2013年11月对东江上游的重要支流—鱼潭江、浰江、车田水、小庙水、彭寨水、沙洲水、罗浮水和黄麻布水进行采样调查,通过计算底栖动物的Shannon-Wiener多样性指数(H′)、Pielou均匀度指数(J)、Margalef丰富度指数(D)和BMWP(Biological Monitoring Working Party)指数,评估了8条支流的生态健康状况。结果显示,东江流域上游共采集到底栖动物109属种,隶属5门、9纲、55科,其中水生昆虫为主要类群,占总物种数的72.4%,EPT类群采集到18属种。研究区域的生物多样性指数较高,物种组成丰富,就不同水体而言,浰江的种类最丰富,小庙水种类数最少,各个支流均以水生昆虫类群占优势。底栖动物平均密度为2362个/m2,平均生物量为39.1 g/m2。河蚬(Corbicula fluminea)为第一优势种,出现率90%,第二和第三优势种分别为涡虫纲一种(Turbellaria sp.)和四节蜉属一种(Baetis sp.)。BMWP指数作为应用广泛的生物评价指数,对河流生态健康的指示作用最强,可达到快速准确的效果。研究表明,东江上游8条支流的生态健康状况总体较好,其中5条河流为极清洁。 相似文献