Australia-wide Assessment of River Health: Australian Capital Territory AusRivAS Sampling and Processing Manual
Cooperative Research Centre for Freshwater Ecology
Monitoring River Health Initiative Technical Report Number 14
Environment Australia, 2002
ISBN 0 6425 4881 1
- Australia-Wide Assessment of River Health: Australian Capital Territory AusRivAS Sampling and Processing Manual (PDF - 910 KB)
About the manual
The term 'river health' is an umbrella term, as is human health, both can be measured and assessed by a range of different indicators. The analogy with human health provides an insight into the complexities of aquatic ecosystem damage and in turn evokes awareness and concern about human impacts on rivers. Traditionally, water quality guidelines have focused on physical and chemical indicators of stream condition. Water quality indicators have undergone a shift in focus with the emphasis toward biological assessment of river condition (Norris and Norris, 1995; Wright, 1995; Resh et al., 1996; Hart et al., 1999; Norris and Thoms, 1999; ANZECC and ARMCANZ, 2000). These recent approaches to river health assessment acknowledge the importance of physical, chemical and biological interactions, recognising the biological end point resulting from the various stressors added to and modifying aquatic systems.
Aquatic macroinvertebrates (i.e., animals without backbones that can be seen with the naked eye, e.g., shrimps, worms, crayfish, aquatic snails, mussels, aquatic stage of some insect larvae, such as dragonfly larvae, mayflies, caddisflies, etc.) are commonly used biological indicators for freshwater resources (Rosenberg and Resh, 1993). Macroinvertebrates are widely used because they are generally abundant throughout the study area, easy to collect and identify, have relatively long life-cycles, and are sensitive to various changes in water and habitat quality. Even if all the appropriate chemical and physical water quality data could be collected at a site it would only be indicative of the status of the river at the moment of sampling. However, measurements of aquatic biota are a more meaningful measure of water quality in that they summarize the preceding river conditions for weeks or months before their collection. For example, an episodic pollution event such as a chemical spill may go undetected by periodic water sampling regimes but damage to the macroinvertebrate assemblage can be detected long after the cause of the impact has pasted. 'Rapid' biological assessment methods have been designed so that macroinvertebrate sample collection, processing, and data analysis is fast and easily done (Resh et al.,1995). Rapid bioassessment methods have facilitated multi-site, regional assessments that were prohibitive to the traditional, intensive-sampling techniques (Parsons and Norris, 1996; Smith et al.,1999; Turak et al., 1999; Marchant et al.,1999).