Queensland Department of Natural Resources and Mines
Monitoring River Health Initiative Technical Report Number 12
Environment Australia, 2002
ISBN 0 642 54879 X
- Queensland Australian River Assessment System (AusRivAs) Sampling and Processing Manual (PDF - 632 KB)
About the Manual
Defining a healthy river is a challenge, despite the fact that we have some idea what it should look like. A healthy river can be described as one that is similar to an unimpacted river of the same type in its natural state (in terms of its water quality, biological diversity and ecological functioning), its condition is stable and it has the capacity for self-repair when disturbed. Although the concept of river health is not new, it is only recently that methods of assessing it have been developed. It extends the traditional approach of using chemical and physical measurements which are often difficult to interpret in biological terms. River health assessment is a way of examining the waterway using tools such as water quality, habitat descriptions, biological monitoring, and flow characteristics to create an overall picture of the ecological health of that waterway. Impacts on the waterway can be varied: chemical spills, riparian vegetation removal, sand and gravel extraction, or stock access. All of these things can upset the balance e.g. a chemical spill might kill a large proportion of the macroinvertebrate community, which is a major component of some fish diets. Consequently, the fish population will be affected.
Water quality and, subsequently, river health has traditionally been assessed solely on the chemical analysis of water samples. In recent years there has been a realisation that the structure of plant and animal communities of the rivers can give us a far more accurate picture of the condition or health of our waterways. Of these biological communities, macroinvertebrates (i.e. animals without backbones, large enough to be seen with the naked eye, e.g. prawns, shrimps, crayfish, snails, mussels and insects such as dragonflies, damselflies and mayflies) are most widely used because they are abundant and diverse, and are sensitive to changes in water quality, flow regime and habitat conditions. Impacts on these animals are relatively long lasting and can be detected for some time after the impact occurs.
The AusRivAS (Australian River Assessment Scheme) model protocol (Simpson et al. 1997) for the MRHI river bioassessment program adapts the RIVPACS (River Invertebrate Prediction and Classification Scheme) methods applied by Wright et al. (1984), Moss et al. (1987), Marchant et al. (1994) and aspects of protocols developed by Chessman (1995). It allows rapid sampling methods to be used for the development of predictive models for macroinvertebrate communities within each state/territory, using a 'reference' site database. Comparisons may then be made between predicted and observed taxonomic compositions of macroinvertebrate communities in different habitats at a site in order to indicate the presence and magnitude of an impact on the site's ecological health. This approach can assess biological responses to changes in water quality and/or habitat condition in rivers and can be integrated with the existing network of physico-chemical water quality monitoring sites.
This document describes the bioassessment methodology adopted by the Freshwater Biological Monitoring Unit of the Department of Natural Resources and Mines, Queensland. It is the protocol used by the Queensland AusRivAS models and is adapted from the River Bioassessment Manual (Davies 1994).
The approach to assessing river health adopted by the National River Health Program (NRHP) (comprising the Monitoring River Health Initiative (MRHI) and First National Assessment of River Health (FNARH)) has generated a lot of interest in the use of biological monitoring of freshwaters in Queensland. Since the Program's inception in 1994, numerous enquiries from public and private agencies on how to develop and implement a biological monitoring program have been made. This manual is intended to provide this information and to encourage the use of standardised methods. The actual protocol used (e.g. sampling design, number of sites, subsampling, replication, frequency of sampling, etc.) should be based on the objectives of the monitoring or assessment program. The protocol outlined in this manual is meant for broad scale monitoring (e.g. catchment or regional basis). For smaller scale and specific issues, other methods using control and replicate sites (such as BACIP and multivariate equivalents) may be more appropriate (see Underwood 1993; ANZECC 2000).
The development of a standardised tool for broad scale bioassessment is dependent on three factors:
- use of the same biota;
- use of the same approach to sampling and sample processing; and
- use of the same analytical methods for model development and use.
The data can also be analysed in different ways and used for other purposes such as impact assessments, condition and trend reporting, biodiversity and biogeographic studies.
It should be noted that this protocol is for use in freshwater reaches of rivers only and not for use in estuaries or tidal reaches of lowland rivers. Although the general approach may be valid, substantial additional work must be performed prior to its adoption in estuarine and marine conditions.