Rapid Bioassessment of Victorian Streams (The Approach and Methods of the Environment Protection Authority)
D. Tiller and L. Metzeling
Environment Protection Agency (Victoria)
Monitoring River Health Initiative Technical Report Number 15
Environment Australia, 2002
ISBN 0 730 67538 6
About this manual
Biological assessment is a key component of EPA's approach to environmental monitoring as water quality is only one of several factors, including in-stream habitat, riparian condition and hydrology which affect aquatic biota.
Physico-chemical monitoring alone provides only a partial assessment of ecosystem health. Furthermore, adverse water quality conditions may go undetected because measurements have not been taken at the right time or under the right conditions, or the right indicator has not been measured. The effects of such events on the aquatic ecosystem may last long after physico-chemical conditions have returned to normal.
The great value in directly monitoring the biological community is that it responds to all types of disturbances and toxicants, and this response can be assessed from infrequent sampling of the community. The aquatic biological community reflects the net effect of all environmental factors, including impacts and stresses over a period of weeks, months or years, effectively summarising the past history of conditions in the stream.
Biological assessment therefore plays a key role in effective monitoring and reporting on the environmental condition of Victorian waterways, with the macroinvertebrate community as the preferred indicator of ecosystem condition.