New metallothionein assay in Scrobicularia plana: heating effect and correlation with other biomarkers

Metallothionein (MT) and other biomarker levels were measured in Scrobicularia plana clams to assess pollution of the Guadalquivir Estuary possibly affected by metals released from Aznalcóllar pyrite mine in 1998. After optimizing reagent concentrations for monobromobimane derivatization, MT levels were quantified by reversed-phase high-performance liquid chromatography coupled to fluorescence detection (RP-HPLC-FD) in heated or unheated digestive gland extracts and compared to those obtained by differential pulse polarography (DPP). MT content assayed by RP-HPLC-FD in unheated samples was higher than that obtained by DPP and correlated better with metals and anti-oxidant activities. MT assay by RP-HPLC-FD in unheated extracts would be preferable for assessing metal pollution, due to its greater sensitivity and specificity. In addition to MT induction, glyoxalase II inhibition was well correlated with metal contents. Our results suggest that metals at the estuary do not originate from Aznalcóllar spill, but from those carried along by the river and deposited at its concave bank.     

Trophic state, ecosystem efficiency and biodiversity of transitional aquatic ecosystems: analysis of environmental quality based on different benthic indicators

Estuaries and coastal lagoons are characterized by a strong spatial and temporal variability of physicochemical characteristics and productivity patterns. In these environments, the magnitude and direction of the ecological responses to inorganic nutrient increase (i.e. eutrophication) are difficult to predict. In the framework of the project, New Indicators of Trophic state and environmental quality of marine coastal ecosystems and transitional environments (NITIDA), we analysed benthic indicators of trophic state, ecosystem efficiency, and environmental quality in four different transitional environments. The trophic state of the sediments was assessed in terms of quantity and bioavailability of sediment organic C pools; ecosystem efficiency was determined in terms of the prokaryote efficiency in exploiting enzymatycally degraded organic C; environmental quality was determined in terms of meiofaunal diversity. Here, we provide a synopsis of the results obtained and a meta-analysis of the scores assessments obtained using the different ecological indicators of environmental quality and demonstrate that trophic state, ecosystem efficiency, and biodiversity in transitional ecosystems are closely linked. We conclude that the assessment of the environmental quality of transitional ecosystems should be based upon a battery of trophic state indicators and 'sensors' of ecosystem functioning, efficiency, and quality.     

Overview of case studies on recovery of aquatic systems from disturbance

An extensive review of the published literature identified more than 150 case studies in which some aspect of resilience in freshwater systems was reported. Approximately 79% of systems studied were lotic and the remainder lentic. Most of the stressor types were chemical with DDT (N=29) and rotenone (N=15) the most common. The most common nonchemical stressors were logging activity (N=16), flooding (N=8), dredging (N=3), and drought (N=7). The variety of endpoints to which recovery could be measured ranged from sparse data for phytoplankton (N=13), periphyton (N=6), and macrophytes (N=8) to relatively more data for fish (N=412) and macroinvertebrates (N=698). Unfortunately the same characteristics were rarely measured consistently among sites. For example, with respect to fish, more than 30 different species were studied and recovery was measured in many ways, most commonly on the basis of: (1) first reappearance of the species, (2) return time of predisturbance densities, and (3) return time of predisturbance average individual size. Based on these criteria, all systems in these studies seem to be resilient to most disturbances with most recovery times being less than three years. Exceptions included when (1) the disturbance resulted in physical alteration of the existing habitat, (2) residual pollutants remained in the system, or (3) the system was isolated and recolonization was suppressed.     

闽江河口湿地资源和保护对策

该文介绍了闽江河口湿地的基本状况，分析了湿地保护中存在的主要问题，提出了保护闽江河口湿地的建议。     

全球气候变化对森林生态系统的影响

人类活动所引起的温室效应及由此造成的全球气候变化和对全球生态环境的影响正越来越引起人们的关注。作为全球陆地生态系统一个重要组分的森林对未来气候变化的响应更是人们关注的重点。文中系统地论述了未来气候变化对森林生态系统树种组成、林分结构、分布和生产力的潜在响应,提出了今后需要加强的一些研究领域。     

城市尾水外排长江口的氧化还原环境监测及其对重金属Hg,Cr形态的影响分析

2001-2002年对上海城市尾水排放对周边水域的影响进行研究,测量了竹园、白龙港尾水排放口水体的氧化还原电位(Eh),并分析了它对重金属形态及其毒性的影响。结果表明,目前上海市城市尾水水下排放并未改变长江口大水体的氧化还原环境,基本以氧化环境为主。重金属元素Hg、Cr主要以Hg(Ⅱ)、Cr(Ⅲ)形态存在,尾水外排不会使Cr毒性增加。     

鸭绿江口滨海湿地环境保护及其资源持续利用对策

阐述了鸭绿江滨海湿地生态环境主要类型及其动植物资源现状、主要生态环境问题及其产生原因 ;提出了鸭绿江口滨海湿地环境保护及其资源持续利用对策     

我国食用海洋生物资源的开发及其对策

在概述我国海域主要的资源生物及其开发现状的基础上,指出在70年代中期以前,随捕捞力量的增加,我国海洋总渔获量增长较快;但此后,尽管捕捞力量仍继续增加,总渔获量增长缓慢。作者认为,过度捕捞、污染以及其他不利的环境因素变化是导致总渔获量缓慢增长的主要原因。为合理利用资源,提高渔获量,应在加强海洋生态系研究的基础上,积极开发外海(包括远洋)资源,并着重发展海洋农牧化。     

Natural and artificial landscape change in a Dutch estuary: partially monitored with low budget method (a study in the fourth dimension)

This study includes ome aspects of the shift in the Dutch attitude in relation to water during the past millennia from defense to attack to keeping the balance(“co-evolution“).It has a special focus on the freshwater tidal part,which embraces the largest of the world:Rotterdam ,as well as the largest national park of the Northerlands.It reports especially about a young mans endeavor in half a c century real time monitoring of some land (scape) units with simple means.