Bunyip – Spring 1993
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BUNYIP – SPRING 1993 Publication 498 May 1996 Introduction salinity, temperature, turbidity, nutrient levels, toxic substances and the amount of oxygen Careful management of our waterways and dissolved in the water. These measures provide catchments is crucial to maintain and improve a ‘snapshot’ of environmental conditions at the river health. Good decision making requires moment samples are taken. Water quality detailed information on the environmental conditions are variable, so such monitoring can condition of our rivers. The Monitoring River fail to detect occasional changes or intermittent Health Initiative – a biological monitoring pulses of pollution. program across Australia – is part of the National River Health Program funded by the In contrast, the biological monitoring program Commonwealth Environment Protection involves sampling aquatic animals, which gives Agency. In Victoria the program is being an indication of the health of the river as a carried out by the Environment whole. Because they live at the Protection Authority (EPA) and site for some time, animals Water Ecoscience (formerly the reflect the build-up of impacts of State Water Laboratory). environmental change on the Caddis fly larva Having undertaken biological river ecosystem – such as the monitoring in Victoria since 1983, influence of surrounding land use EPA has a great deal of experience in the field. or the effects of pollution. The results of previous studies will be combined with those of the current program, providing a solid background of data. This will be used to Biological monitoring techniques determine long-term trends in the health of our Aquatic macroinvertebrates (such as insects, rivers and will help the protection of water snails and worms) are very useful indicators in quality and the beneficial uses of our water biological monitoring. They are visible to the courses. naked eye and are commonly found in rivers and streams. They are an important source of food for fish and many are well known to anglers – Monitoring water quality such as yabbies, mudeyes, stoneflies and Traditional water quality monitoring involves mayflies. They are widespread, easy to collect, measuring physical and chemical aspects of the relatively immobile and provide good water. Common measurements include pH, information about the environment. The presence or absence of specific species ¨ Kick samples provides information about water quality. Some To conduct kick samples, the stream bed species are known to have particular tolerances is disturbed by the sampler’s feet to to environmental factors such as temperature or dislodge animals which are swept into a net levels of dissolved oxygen. Other information can by the current. Samples are taken from be obtained from the number of species found at shallow areas with stony or rocky a site (biological diversity), the number of animals substrates in medium to fast currents. This found at a site (abundance) and the relationship type of habitat is called a riffle and is usually between all animals present (community associated with upland streams. structure). ¨ Sweep samples Sites with a high level of species diversity Sweep samples are collected by sweeping generally have good water quality. Sites which a net along banks and around snags in have low diversity are less healthy – often due to backwaters and pools which have slow the impacts of pollution. In polluted habitats, currents. Aquatic plants (macrophytes) – sensitive species are eliminated and less sensitive which provide additional habitat for aquatic species show an increase in numbers. animals – are often found in these habitats and are included in the sweep sample. Reporting results These habitats can be found in both the upland and lowland reaches of rivers. By the end of the three year biological monitoring program, a base of biological Water quality measurements are made at each assessment will have been completed for all the site and water samples are taken for laboratory major river basins in Victoria. analysis. The vegetation along the river banks (the riparian zone) and the aquatic habitat are also This series of bulletins will provide a brief assessed. The aquatic habitat is those parts of summary of the data for each river basin as it the river environment which animals use to make becomes available. Comprehensive a home. It can be strongly affected by the riparian assessments will be published following zone as well as the environment and land use of completion of the program. surrounding and upstream regions. Study site selection and assessment For example, if fertiliser runoff is causing an excess of nutrients to enter the river, there may Monitoring sites are selected to include a be excess growth of algae attached to rocks and variety of sites believed to be representative snags in the river, affecting these important of the river basin’s waterways. habitats. It can also result in Sites subject to the impact of blooms of toxic blue-green algae pollution and those which are which are potentially hazardous relatively unimpacted are to humans, animals and birds chosen, although most are contacting or consuming the situated away from any obvious water. Thus different factors can point source of pollution. influence many parts of the river environment. Biological Sites are currently being sampled monitoring can be a valuable tool twice a year (autumn and spring) to measure the overall effect of using the rapid bioassessment all these influences. technique. This involves collecting two types of biological samples where possible. Riparian habitat Figure 1 Species numbers at sampling sites in the Bunyip Basin – Spring 1993 BUNYIP BASIN REPORT – SPRING 1993 Comments cating significant catchment disturbance. The num- ber of species in Bunyip River was comparable to The Bunyip basin comprises four rivers and several other sites, despite both kick and sweep samples creeks which flow into Port Phillip Bay and West- being taken. This suggests some problems at the ern Port. site – either water quality or poor quality habitat. The land in the area has been used extensively for Nutrients levels exceeded EPA’s guidelines at all agriculture since European settlement. As well as sites. Nitrogen at Clematis Creek and phosphorous the usual disturbances associated with agriculture, at Cardinia Creek at Manks Road, Tarago River extensive drainage of swamps has occurred and and Lang Lang River were above recommended waterways have been modified to act as drains. levels. Both nutrients were excessively high at Large urban and industrial areas are also located in Eumemmerring Creek, Cardinia Creek at the basin. Problems in the basin thus include the re- Beaconsfield, Bunyip River at Evans Road, and duced number of habitats available, various pollutants Dandenong Creek. and increased nutrients. Figure 1 is a map of the basin showing monitoring Species numbers were moderate at most sites. Spe- sites and the number of species collected at the sites. cies tolerant of various stresses were common at Site 6 was not sampled on this occasion due to dif- most sites. ficulties with access. Dandenong Creek (site 2) showed evidence of in- creased nutrient levels, with significant growth of Related EPA Publications attached algae. The fauna was dominated by an in- troduced aquatic snail and a midge, both of which State Environment Protection Policy – Waters of are tolerant of organic enrichment. Dandenong Valley Victorian Government Gazette No. S12, Eumemmerring Creek and Cardinia Creek at 24 February 1988 Manks Road (sites 3 and 5) had relatively low spe- cies richness, with most species being tolerant of State Environment Protection Policy – Waters of many environmental stresses. Western Port Bay and Catchment Victorian Government Gazette No. 12, Lang Lang River (site 9) supported comparatively 9 February 1979 rich fauna – probably due to the extensive and di- verse aquatic plant growth. Nutrient concentrations Preliminary Nutrient Guidelines for Victorian were relatively high and apparently promoting plant Inland Streams growth. EPA Publication No. 478, June 1995 The number of species in Bunyip River and Clema- tis Creek (sites 8 and 1) was expected to be higher Further Information than at other sites, as these were the only sites where EPA Customer Service & Information Centre both kick and sweep samples could be taken. Al- Olderfleet Buildings though the fauna of Clematis Creek was reasonably 477 Collins Street, Melbourne 3000 rich and typical of good water quality, siltation and Telephone: (03) 9628 5622 relatively high nutrient levels were observed, indi-.