An ecosystem consists of all the biological organisms and the physical environments they occupy together within a defined area [1]. The actual boundaries of an ecosystem are generally defined by researchers studying the ecosystem, who are usually interested in understanding the processes that control some aspects of ecosystem dynamics. Thus, the spatial domain of an ecosystem might range in siz...

Catfishes (Siluriformes: Pimelodidae) in the Amazon River Basin serve important ecological and economic roles in structuring foodwebs, transferring nutrients and providing food resources for human populations. Large-scale developments such as construction of the Interoceanic Highway and associated proposed hydroelectric facilities could lead to alterations in river hydrology and aquatic ecosyst...

River field surveys are carried out to describe biological habitats and the main geomorphic features of a river stretch. They can be extensive, expensive and time consuming campaigns sampling a high number of features. These features belong to a complex river ecosystem characterized by many different processes at various scales from simple to highly non linear. Researchers need sophisticated te...

In this study, the onion (Allium cepa) root test was used to evaluate the genotoxicity of the Pitimbu River (Natal city, Brazil) surface water. The water was collected at five sampling sites along the river and one sample was obtained after the treatment (flocculation, chlorination and pH correction) of the river water for human consumption. All raw river water samples increased the frequency o...

The Qiantang River is a typical freshwater ecosystem that acts as an irreplaceable water source in Zhejiang Province in southeastern China. However, the effects of environmental factors on the bacterial community of this freshwater ecosystem have not been determined. In this study, seven sediment samples were collected along the river. Their bacterial communities were identified using 454 high-...

We examined primary production, respiration, and nutrient dynamics in littoral areas of the mainstem and lagoons of the Cinaruco, a nutrient-poor river in the Venezuelan llanos. Gross primary productivity (GPP) was relatively high, given the poor nutrient conditions in this river. Seasonal variability in net ecosystem production (NEP) was also high, with highest values occurring in the dry seas...

This study evaluated integrative river ecosystem health using stressor-based models of physical habitat health, chemical water health, and biological health of fish and identified multiple-stressor indicators influencing the ecosystem health. Integrated health responses (IHRs), based on star-plot approach, were calculated from qualitative habitat evaluation index (QHEI), nutrient pollution inde...

The development of the Water Framework Directive aimed to establish an integrated framework of water management at European level. This framework revolves around inland surface waters, transitional waters, coastal waters and ground waters. In the process of achieving the environment and ecological objectives set from the Directive, the role of economics is put in the core of the water managemen...

Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We stud...