Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004-2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinat...

The physical characteristics of river systems exert significant control on the habitat for aquatic species, including the distribution of in-stream channel habitat units. Most previous studies on channel habitat units have focused on midlatitude rivers, which differ in several substantive ways from tropical rivers. Field delineation of channel habitat units is especially challenging in tropical...

Dryland alluvial rivers vary considerably in character. In terms of processes, high energy, sediment-laden flash floods in upland rivers contrast dramatically with the low sediment loads and languid flows of their lowland counterparts while from a form perspective, the unstable wide, shallow and sandy braid plains of piedmont rivers are quite different from the relatively stable, narrow, deep a...

Understanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences ...

The management of urban water resources plays an important role for developing countries. The Tietê and Pinheiros Rivers (São Paulo, Brazil) are affected by domestic and industrial effluents and by the diffuse pollution. This research aimed to quantify 134 variables in the water of Tietê and Pinheiros Rivers (approximately 7,200 and 6,600 analyses, respectively) from August 2007 to December 200...

Although the process of eutrophication is reasonably well understood in lakes, there is currently no conceptual understanding of how eutrophication develops in rivers. This issue is addressed here. A review of the main processes controlling the development of eutrophication in lakes has been carried out as a precursor to considering the effect in rivers. The importance of hydraulic flushing in ...

A new species of Pseudancistrus is described from the Tapajós Basin, and assigned to the P. barbatus group by having hypertrophied odontodes along the snout and lacking evertible cheek plates. The new species is distinguished from other species in that group (P. barbatus, P. corantijniensis, P. depressus and P. nigrescens) by its pattern of spots, length and color of snout odontodes, greater he...

The variation of a number of parameters characterizing aquatic plant assemblages in rivers across a wide trophic gradient was investigated to evaluate their usefulness for a Polish national river monitoring system. Analyses were conducted at 100 sites included in the national river monitoring system, representing a uniform river type, i.e., small- and medium-sized lowland rivers with a sandy su...

s for these talks are published in the GSA Abstracts With