What is river health?

Abstract

Summary 1. Traditionally the assessment of river water quality has been based solely on the measurement of physical, chemical and some biological characteristics. While these measurements may be efficient for regulating effluent discharges and protecting humans, they are not very useful for large‐scale management of catchments or for assessing whether river ecosystems are being protected. 2. Measurements of aquatic biota, to identify structural or functional integrity of ecosystems, have recently gained acceptance for river assessment. Empirical evidence from studies of river ecosystems under stress suggests that a small group of biological ecosystem‐level indicators can assess river condition. However, physical and chemical features of the environment affect these indicators, the structure and function of which may be changed by human activities. 3. The term ‘river health’, applied to the assessment of river condition, is often seen as being analogous with human health, giving many a sense of understanding. Unfortunately, the meaning of ‘river health’ remains obscure. It is not clear what aspects of river health sets of ecosystem‐level indicators actually identify, nor how physical, chemical and biological characteristics may be integrated into measures rather than just observations of cause and effect. 4. Increased examination of relationships between environmental variables that affect aquatic biota, such as habitat structure, flow regime, energy sources, water quality and biotic interactions and biological condition, are required in the study of river health.

Bacteria and phytoplankton production rates in eight river stretches of the middle Rio Doce hidrographic basin (southeast Brazil)

“…On the other hand, the lack of a clear pattern concerning PPP variation prevented this variable of being used in this sense. Nevertheless, the inclusion of other explanatory variables not considered in the present research (e.g., flow velocity and underwater radiation), as suggested by Norris and Thoms (1999), would certainly improve the idea proposed, and probably bring new conclusions concerning PPP and BSP measurements.…”

“…For example, the importance of rains in determining seasonality in tropical aquatic ecosystems is well known (Norris and Thoms 1999), but the effects of this functioning force upon BSP and PPP in tropical rivers are poorly understood. The same can be considered about the longitudinal patterns of BSP and PPP in lotic ecosystems.…”

River health assessment in a large river: Bioindicators of fish population

“…The ecological status of these regions stayed in a good condition for the establishment and good supervision to the Reserve. Compared with AY and XW, all the sampling sites in Guangdong Province were assigned as "impaired", and the possible incentive was severe human activities including mining, land use, artificial drainage systems construction and fishing (Karr, 1991;Norris and Thoms, 1999). There exist about 1700 mines along the Dongjiang River in Guangdong Province.…”

Linking Ecological and Perceptual Assessments for Environmental Management: a Coral Reef Case Study

“…Combining information from both expert and lay communities in environmental management generally provides a more complete picture of environmental circumstances than does information collected from one perspective alone (Schaeffer 1996, Boulton 1999, Norris and Thoms 1999. In this coral reef case study, the ecological measures describe changes in the amount of damage and the cover of branching and soft corals associated with anchoring, and the perceptual meanings indicate Fig.…”