Application of the Australian river bioassessment system (AUSRIVAS) in the Brantas River, East Java, Indonesia

Journal of Environmental Management (2001) 62, 93–100 doi:10.1006/jema.2001.0424, available online at http://www.idealibrary.com on

Application of the Australian river bioassessment system (AUSRIVAS) in the Brantas River, East Java, Indonesia B. T. Hart†* , P. E. Davies‡ , C. L. Humphrey§ , R. N. Norris¶ , S. Sudaryanti†† and Y. Trihadiningrum‡‡

Assessment of river ‘health’ using biological methods, particularly those based on macro-invertebrates, is now commonplace in most developed countries. However, this is not the case in most developing countries, where physical and chemical methods are used to assess water quality, with very little use of biological assessment methods. This paper reports on a project that aimed to assess the possible introduction of biological assessment of river condition using the Australian River Assessment System (AUSRIVAS) into Indonesia. The paper addresses three components of the project: (1) science—does the bioassessment method work in this tropical region? (2) resources—are they adequate and if not what additional resources are needed? (3) politics—what needs to be done to convince the agencies (both central and provincial) to take up such a new philosophy and approach? A pilot study was run in the upper Brantas River, East Java. A total of 66 reference sites and 15 test sites were sampled and the macro-invertebrates collected were identified to family level. A rigorous quality-control protocol was introduced to ensure the data were reliable and reproducible. The macro-invertebrate data were used to develop a predictive model of the AUSRIVAS type for the upper Brantas River, and the model was then used to assess the ‘health’ of sites that were presumed to be damaged in this section of the river. A number of difficulties were experienced during the study, including: locating reference sites sufficiently unmodified by humans; lack of skills to identify animals collected; and a paucity of facilities required for aquatic macro-invertebrate identification (e.g. identification keys and good quality binocular microscopes). For resources, the major constraint to the introduction of a bioassessment capability in Indonesia is the lack of personnel trained in the bioassessment techniques. An ‘on-the-job’ training approach was adopted, largely because of the specialist nature of this work. Six Indonesians were trained and will now become the ‘trainers’ of further Indonesian scientists (we have called this process ‘training-the-trainers’). For politics, it was hoped that the AUSRIVAS method would be suitable for introduction into the Indonesian national Clean River Program. A strategy was developed and implemented to ensure the method and its outputs were accepted technically by the Indonesian scientific community, and also by the resource managers and relevant government officials. Experience shows that if the latter do not see how the bioassessment information will be used for management purposes they will not accept the method even if it is scientifically sound.  2001 Academic Press

Keywords: bioassessment, macro-invertebrate, tropical, AUSRIVAS, Indonesia, Brantas River, training, resource management, river health.

Introduction The use of biological methods to assess the ‘health’ of rivers is now well developed in many countries. For example, the UK and Australia have national bioassessment programs based on rapid biological methods employing macro-invertebrates (Wright, 0301–4797/01/050093C08 $35.00/0

1995; Norris et al., 1995; Schofield and Davies, 1996), and the methods are used widely in the USA and Canada (Reynoldson and Metcalf-Smith, 1993). In Australia, the Australian River Assessment System (AUSRIVAS) method has been developed since 1994, and is now used in all Australian states and territories (Norris et al., 1995; Schofield and Davies, 1996;

* Corresponding author † Cooperative Research Centre for Freshwater Ecology and Water Studies Centre, Monash University, Wellington Road, Clayton 3800, Australia ‡ School of Zoology, University of Tasmania, GPO Box 252 C-5, Hobart, Tasmania 7005 Australia § Environmental Research Institute of Supervising Scientist, GPO Box 461, Darwin, NT 0801, Australia ¶ Cooperative Research Centre for Freshwater Ecology, University of Canberra, P.O. Box 1, Belconnen, ACT 2616 Australia †† Faculty of Fisheries, University of Brawijaya, Jl. Veteran, Malang 65145, Indonesia ‡‡ Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Jl. AR Hakim, Surabaya, Indonesia Received 20 August 1999; accepted 22 January 2001  2001 Academic Press

94

B. T. Hart et al.

Simpson and Norris, 2000). This rapid bioassessment method is based on the UK RIVPACS method (Wright et al., 1993), and is being used by environmental and resource management agencies to assess both the ecological condition (‘ecological health’) of their resources and the effectiveness of various management actions (Schofield and Davies, 1996). The AUSRIVAS method, like those employed in other countries, is based on the presence and absence of aquatic macroinvertebrates, and compares the numbers and types of animals found at a site with those predicted to be present on the basis of a model derived using data from minimally degraded reference sites (Wright, 1995; Simpson and Norris, 2000). Perhaps the most important aspect of this method is that the comparisons are based on local information, and not on information from overseas (implicit in many of the biotic indices applied to Indonesian streams and in the adoption of chemical water-quality standards). It is unfortunate that there is little use of biological methods in most developing countries, where physical and chemical methods are still the ones of choice to assess water quality. For example, in Indonesia the national Clean Waters Program (PROKASIH) is based almost entirely on physical and chemical indicators, with little use of biological assessment methods (Trihadiningrum et al., 1999). Also, those biological methods that have been used are heavily influenced by overseas information, the relevance of which to Indonesia has not been tested. There is certainly a growing interest in introducing biological assessment methods in many developing countries. However, this is not a simple process. This paper reports the outcomes of a project that aimed to assess the possible introduction of the AUSRIVAS method into Indonesia. The paper argues that three aspects must be considered: (1) science, it needs to be demonstrated well that the chosen bioassessment method does work. Many developing countries are in tropical or semi-tropical regions, where conditions are very different to the regions where most of the bioassessment methods have been developed; (2) resources, both human and equipment resources must be adequate to support the new bioassessment method; the

lack of skilled macro-invertebrate biologists in most developing countries may be a major constraint; (3) politics, it is not sufficient for a bioassessment method to be shown to work scientifically. The various resource management and environmental agencies (both central and provincial) who will use the method and the data produced, need to be convinced that the new method is viable, cost-effective and that the data will help them in their management.

The science The first challenge was to demonstrate that the AUSRIVAS bioassessment method does work in Indonesia. Since macro-invertebrate communities have been successfully used for bioassessments in northern Australia (e.g. Humphrey et al., 1995), a region with similar tropical characteristics to East Java, we were confident that the method would be successful in Indonesia. The Brantas River, East Java (Figure 1) was chosen as the study catchment for the AUSRIVAS trial. The Brantas was ideal for the following reasons. First, it is a major river in the highly populated East Java province and is one of the priority catchments of the Indonesian Government; second, East Java (and hence the Brantas catchment) is the focus of the AUSAid-funded PCI project. Third, there have been several water quality and bioassessment studies conducted on the Brantas River (Sudaryanti, 1999; Trihadiningrum et al., 1999); and finally, there was a high level of interest expressed in undertaking this study from three local universities (Brawijaya, Airlangga, Institut Teknologi Sepuluh Nopember, Surabaya (ITS)), the East Java BAPEDALDA (the East Java Environmental Protection Agency) and Jasa Tirta (the Brantas River catchment management agency). The Brantas river is the longest river in East Java (320 km), with a catchment area of 12 000 km2 , which is divided into three main sub-catchments (upper, middle and lower Brantas; Figure 1). The river has its source on the south-western slope of Mount Arjuno from which it runs west and then north to enter the Madura Strait at Surabaya. The river is regulated with flow controlled by twelve reservoirs, the largest

Bioassessment of the Brantas River, Indonesia

being Sutami Reservoir. The mainland uses in the catchment are natural forest, forestry, agriculture, human settlement and industry. The water of the river is used for drinking, agriculture, washing and waste disposal. The Brantas River has degraded water quality and ecological health, especially in its lower reaches (Susilo et al., 1994; Sudaryanti, 1997, 1999). The numbers of indigenous fish have decreased, severe eutrophication problems exist, and there is high organic pollution (BOD). There are many domestic and industrial sources of pollution in the Brantas catchment. A total of 13Ð72 million people, 42% of East Java’s population, live in the basin at present, and the rate of population growth is a cause for concern. In addition, there are more than 720 industries registered in the Brantas basin, with 459 of these assessed as potential polluters of the river (Sudaryanti, 1997). Human activities, such as sand and stone removal, land clearing and agricultural pollution, have also impacted upon the river. The eruption of Mount Semeru and Mount Kelud resulted in additional sediment being added to the river, with consequent changes to the original habitat. Konto subcatchment

N

The study was undertaken in the upstream section of the Brantas catchment, which covers an area of 2050 km2 , and which can be divided into four sub-catchments (Amprong, Metro, Lesti and Lahor, Figure 1). Amprong contains a combination of young and old volcanic rocks, Metro and Lahor are dominated by young volcanic rocks, and Lesti contains a combination of young and old volcanics, as well as limestone (Konto River Project, 1989). Sampling of 66 reference sites (leastdisturbed) and 15 test sites (disturbed) was carried out from June to July 1998 (see Figure 1). Details of the sampling methods, laboratory processing (subsampling, sorting, identification) and data analysis are provided by Sudaryanti et al. (1999, 2001), AUSRIVAS (2000) and Simpson and Norris (2000). Macro-invertebrates were identified to family level with the exception of Oligochaeta (Class), Acarina (Order), Collembola (Order), Turbellaria (Order) and Chironomidae (subfamily). An extensive range of environmental variables (such as latitude, longitude, altitude, distance from the source and many local habitat characteristics) were also measured

Mt Arjuno Amprong subcatchment

Malang city

Mt Kelud Mt Kawa Lahor subcatchment

Mt Bromo

Mt Semaru

Brantas River

Lesti subcatchment Metro subcatchment

Surabaya Malang

Sumatra Java

0

5 Scale (km)

10

Celebes New Guinea

Timor

Figure 1. Upper Brantas catchment showing location of reference and test sites. Group I sites, r, group II sites, r, group III sites, , group IV sites, , test sites, .

95

96

B. T. Hart et al.

at each site. It is important to note that these procedures were based on standard protocols derived from the AUSRIVAS program (AUSRIVAS, 2000; Simpson and Norris, 2000), and that all aspects were supervised closely by a number of experienced Australian trainers. The macro-invertebrate and habitat data collected at the reference sites were analysed and used to build an AUSRIVAS-type predictive model for the upper Brantas (see Sudaryanti et al., 2001; Simpson and Norris, 2000, for detailed descriptions of model building). More detail on the data analysis method is provided by AUSRIVAS (2000) and Simpson and Norris (2000), and on the nature of each classification group by Sudaryanti et al. (1999, 2001). Macro-invertebrate and habitat data were collected from 15 sites judged to be damaged. These data were then analysed to provide an assessment of the ecological health of the site compared with the reference sites in the model (Simpson and Norris, 2000; Sudaryanti et al., 1999, 2001). Only those taxa which had a probability of 50% or greater of occurring at a test site, were used to calculate the number of expected (E) taxa (the sum of the probabilities of those predicted (Wright, 1995)). The observed (O) number of taxa was obtained by summing the number of taxa actually recorded at the site with expected probabilities ½50%. The O/E

index was calculated to provide a measure of the difference between the observed and expected macro-invertebrate distributions. An O/E ratio near 1 is equivalent to reference while a ratio less than about 0Ð8 indicates about 20% of the expected taxa were missing and the site is below reference condition (Simpson and Norris (2000) discuss bands of impairment). The O/E index and ecological health rating for the 15 test sites within the upper Brantas catchment are provided in Table 1, and are seen to range from equivalent to reference to severely degraded. A summary of the main features is provided below. A more detailed discussion is provided by Sudaryanti et al. (1999, 2001).

Kemulan stream This had the highest O/E value. It was placed in the A band, meaning that the number of macro-invertebrate families found at this site was similar to the number expected. This stream has habitat that is dominated by riffles, largely a cobble substratum, a fast current velocity for this mid dry season sampling period (0Ð68 m/s), and a high dissolved oxygen concentration (7Ð4 mg/l). Riparian vegetation is extensive and intact on both banks of the stream. Rice fields are the main land use in this subcatchment.

Table 1. O/E index and ecological health rating for test sites in the upper Brantas Site L2-52 A2-25 A2-3 A2-44 At-76 L2-21 L2-51 A1-43 Lt-75 M1-10 M2-67 M2-79 M2-80 Mt-37 Mt-65

Stream

O/E

Rating

Kemulan Rais Brantas Tembungan Kidul Dargo Sumberungkal Brantas Njaruman Gendogo Babar Sat Claket Gowok Sumber Pulo

1Ð10 0Ð45 0Ð26 0Ð44 0Ð53 0Ð68 0Ð63 0Ð53 0Ð88 0Ð67 0Ð54 0Ð64 0Ð64 0Ð68 0Ð28

Equivalent to reference Moderately impacted Severely degraded Moderately impacted Mildly impacted Mildly impacted Mildly impacted Mildly impacted Equivalent to reference Mildly impacted Mildly impacted Mildly impacted Mildly impacted Mildly impacted Severely degraded

E, number of taxa expected from those predicted with >50% probability of occurrence; 0, number of taxa observed from the list of those with >50% probability of being at the site; O/E, Observed/Expected ratio. This should be near 1Ð0 for sites similar to reference conditions in the Brantas river. Sites with O/E <0Ð84 are below reference in the Brantas river catchment.

Bioassessment of the Brantas River, Indonesia

Sumberungkal stream

Temporal variability

This had slightly poorer quality and was rated as mildly damaged. Non-point source pollution from the ricefields and dry cropping in this sub-catchment, contributed gravel and sand to the sediments, are probably the main reasons for the slight degradation. In addition, the stream had little riparian vegetation, a riffle and pool-type habitat, with medium/current velocity, and a dissolved oxygen concentration of 6.0 mg/l.

A key assumption in developing AUSRIVAStype predictive models is that, in the absence of human disturbance, macro-invertebrate communities remain relatively constant over time. Australian research has shown that macro-invertebrate constancy is proportional to the temporal variability in river discharge (inter-annual) as well as to the degree of seasonality of the flow relative to the sampling times (Humphrey et al., 2000). Australia certainly has cause for concern in this respect, since average values for the coefficient of variation (CoV) of annual stream flows are amongst the highest of all regions around the world (CoV—South Pacific, 0Ð25; Europe, 0Ð28; North America, 0Ð29; Asia, 0Ð35; northern Africa, 0Ð37; South America, 0Ð52; Australia, 0Ð69; and southern Africa, 0Ð79). The low CoV value for Asia suggests that predictive models for Indonesia are not likely to be confounded because of temporal variability in the macro-invertebrate communities. Much of Indonesia is also largely free of cyclonic activity—disturbance to streams which may alter stream macro-invertebrate communities severely (Humphrey et al., 2000). However, more work still needs to be done on the extent and degree of temporal variability of macro-invertebrate communities in Indonesian streams.

Tembungan stream This was even more degraded (C rating). Many of the expected macro-invertebrate families were not found, indicative of streams where human activities have lead to moderate impact on the river quality.. The main land use in this subcatchment is dry cropping (cabbage growing). In addition, the stream has poor riparian vegetation, a sand, gravel and silt substratum, with a medium/current velocity.

Main Brantas River The Brantas River, site A2-3, was severely degraded (rated D), with very few of the expected macro-invertebrate families found. The stream still has reasonable riparian vegetation, a substratum consisting of cobble, pebble, gravel, sand and silt, with a medium current velocity. The main land use is a combination of natural forest, forestry activities and dry cropping. These test sites seem to be degraded because of non-point source pollution and erosion, and also sand removal activities. The effect of pesticide use in this region is not known, but could be significant.

Current or potential constraints The trial highlighted a number of areas where additional work and resources will be required if the AUSRIVAS method is to be successfully introduced nationally in Indonesia. These are discussed below.

Reference sites The selection of essentially unmodified reference sites was difficult in many regions of the upper Brantas, because of the high level of human activity in almost all regions of the catchment. This is expected to be a major problem in most catchments in Indonesia (and many other developing countries), and particularly for the lowland reaches of major rivers. Often it is possible only to use the best available sites as reference sites. Sometimes it is possible to use reference sites in adjacent catchments that are in better condition. Even it this is not possible, the models developed using the best available, but already modified reference sites, can still be useful as a baseline for judging change.

97

98

B. T. Hart et al.

Quality assurance and quality control In order that the results of a monitoring program are comparable between different locations, times and operators, it is necessary to employ standard procedures to help control the quality of the data collected. Quality control (QC) and quality assurance (QA) programs need to be established for both the field and laboratory components of the monitoring. QA/QC procedures, ideally, require about 10% of the program budget. Some aspects of the bioassessment process, namely the sorting and identification stages, were evaluated by the Australian team members by undertaking a second analysis of most of the samples and recording any taxa missed or misidentified by the first Indonesian operator. Some difficulties were experienced in incorporating a QA/QC procedure for the identification of some specimens, e.g. Mollusca, because these require consultation with a skilled taxonomist.

Taxonomy Biological assessment based upon macroinvertebrate assemblages requires that the different kinds of animals found in the rivers are distinguished, if not accurately identified. At the family taxonomic level, most of the animals collected in the Brantas can be identified, but there are still some types of animals that are difficult and may be unknown. Here, most problems were experienced with trichopterans and gastropods. During the trial, difficulties were experienced because of the lack of up-to-date taxonomic keys. Some consolidation of the small number of available and relevant taxonomic keys was possible during the trial. Nevertheless, there is still an urgent need to produce a ‘guide to freshwater invertebrates of Indonesia’.

Facilities The project was able to provide some much needed equipment (e.g. microscopes, subsampling devices, nets, identification keys). However, if macro-invertebrates are to be used generally to assess the ‘health’ of Indonesia’s rivers, additional equipment,

including water-quality meters, will be required. It should be noted that the training and capital investment required for this equipment is tiny by comparison with that needed for setting up a chemical analysis laboratory.

The resources Above some of the resource implications in attempting to introduce bioassessment methods in developing countries were identified. In particular, the lack of taxonomic keys and specialist taxonomists, and a general lack of sampling and identification equipment are two very real constraints. There is also a lack of personnel trained in bioassessment techniques. The training program adopted for this project was quite different from that used in many aid-funded projects. We adopted an ‘on-the-job’ training approach, largely because of the specialist nature of this work. A total of six people were selected for training, and they actually undertook the whole AUSRIVAS program—from initial site selection, through sampling, sorting and identification of the macro-invertebrates collected, and eventually to developing the predictive computer model for the upper Brantas. This ensured that ownership of the project rested with local trainees and other Indonesian agencies consulted throughout the project. It also ensured thorough first hand, practical experience of all aspects was gained by the participants. The training was undertaken continually over 3 months from June to August 1998. At all times one Australian ‘trainer’ (a person skilled and experienced in all aspects of the bioassessment method) worked directly with the group. During the first 4-week period, when reference sites were being selected, two Australian trainers worked with the group. The six trained personnel will now form a nucleus of skilled people in Indonesia who will be able to train further personnel. Therefore, they will be the ‘trainers’ of further Indonesian scientists—we have called this process ‘training-the-trainers’. Three of the Indonesian trainers are based at universities and they will be particularly important because they have a direct link in training new graduates in the skills needed.

Bioassessment of the Brantas River, Indonesia

The very real commitment needed from both those being trained and their organisations must not be understated. If bioassessment is to proceed at regional or national levels in Indonesia, it is essential that agencies are committed to the program and are able to release key staff for such in-depth training. We view having achieved this as a major success of the project.

The politics Readers who work with a resource management agency will be well aware that having a particular bioassessment method that has been shown to be scientifically credible and capable of producing useful results, is not enough to ensure that it will be adopted for general use. There is still a great deal to be done to convince the agencies (both central and provincial) that a new method is viable, cost-effective and that the data produced will help them in their management. From the start of this project, and with the assistance of the Steering Committee, it was recognised that if the AUSRIVAS method was to be introduced into Indonesia on a national scale, the method and its outputs needed to be familiar and accepted. Two levels of acceptance were recognised: (1) acceptance of the technical aspects of the method by the Indonesian scientific and technical community; (2) acceptance of the method and its outputs by the resource managers and relevant government officials (we worked on the principle that if they could not see how the bioassessment information would be used for management purposes it would not be accepted even if it was scientifically sound). Four strategies were used in an attempt to ensure the AUSRIVAS method was well publicised and the results accepted. It was assumed that, as with any well-structured program, the project needs to be in place, publicising the method and results, if general acceptance is to be obtained. The four components were: (1) PR brochure. A simple brochure explaining the purpose of the project, who was involved and the activities to be undertaken was prepared (in both English and Bahasa Indonesian) and widely circulated very early in the project. (2) Initial workshop. A 2-day workshop was

run to explain the AUSRIVAS method to those likely to be involved in the project, and to use their expertise to decide on suitable reference sites. (3) Scientific workshop on river bioassessment. A 1-day workshop was run to explain the AUSRIVAS method and seeking acceptance from the Indonesian scientific community. The success of this workshop was dependent on it being run by our Indonesian colleagues. (4) National Conference on River Health Bioassessment. This 3-day national conference, again organised by our Indonesian colleagues, was aimed at scientists, resource managers and policymakers. On day 1 the basics of the AUSRIVAS method were presented, and the results of the Brantas River trial were presented and explained. Day 2 involved taking the participants to a number of the sampling locations and showing them the techniques involved in macro-invertebrate sampling. Then on Day 3, high level representatives from the key Indonesian resource management agencies indicated how their organisations would use the bioassessment information. In all cases, these key players pledged their full support for the method and its acceptance in Indonesia. (5) Discussions with key government and agency officials. At every opportunity Indonesian and Australian members of the project held discussions with individuals in key resource management and environmental agencies and government departments, aimed at explaining the bioassessment method and gaining their support for the introduction of the method into Indonesia. In principle, agreement has been given by BAPEDAL to introduce the AUSRIVAS method into the national PROKASIH program and a high level Technical Committee, chaired by an academic, has been established to implement its introduction.

Acknowledgements We are grateful to a large number of individuals and organisations that assisted in the PCI project. Lisa Thurtell, Ruth O’Connor and Justen Simpson trained the ‘trainers’. Rosmanida, Sri Unon Purwati, Hadi Supriyanto and Linda Yuliyanti all assisted splendidly in the Brantas trial. Our PCI Project colleagues (Dr Warwick Forrest, Tim Wrigley and Geoff Penhall) gave their assistance and advice freely. We thank the six Indonesian organisations that made time available for their

99

100

B. T. Hart et al. staff to undertake the on-the-job AUSRIVAS training and participate in the associated workshops and conferences (Brawijaya University, ITS, Airlangga University, Bapedal, EJ Bapedalda, Jasa Tirta). Brawijaya University also provided the facilities for the training course and the National Conference; in particular the support of the Rector (Professor Dr Eka Afnan Troena) was greatly appreciated. Professor Dr Kasumbogo Untung, Special Assistant to the State Minister of the Environment, is thanked for his contributions during the Workshop and National Conference, and for his general support for bioassessment. The study was funded by AUSAid through the BAPEDAL (Indonesian Federal EPA) and East Java Pollution Control Implementation Project (PCI Project).

References AUSRIVAS (2000). The AUSRIVAS web-site: http://ausrivas.canberra.edu.au Humphrey, C. L., Faith, D. P. and Dostine, P. L. (1995). Baseline requirements for assessment of mining impact using biological monitoring. In the use of biota to assess water quality, Australian Journal of Ecology 20, 150–166. Humphrey, C. L., Storey, A. W. and Thurtell, L. (2000). AUSRIVAS: operator sample processing errors and temporal variability—implications for model sensitivity. In Assessing the Biological Quality of Freshwaters: RIVPACS and Other Techniques (J. F. Wright, D. W. Sutcliffe and M. T. Furse, eds), pp. 143–146. Cumbria: Freshwater Biological Association 2000. Konto River Project (1989). Studi Screening DAS Brantas. Laporan Utama, Vol I, Peta. Volume III, Direktorat Jenderal Reboisasi dan Rehabilitasi Lahan. Departemen Kehutanan. Direktorat Jenderal Kerjasama International, Departemen Luar Negeri, Kerajaan Belanda. Norris, R., Hart, B. T., Finlayson, M. and Norris, K. R. (1995). Use of biota to assess water quality. Australian Journal of Ecology 20, 1–227. Reynoldson, T. B. and Metcalfe-Smith, J. L. (1993). An overview of the assessment of aquatic ecosystem health using benthic invertebrates. Journal of Aquatic Ecosystem Health 1, 295–308. Schofield, N. J. and Davies, P. E. (1996). Measuring the health of our rivers. Water 23, 39–43.

Simpson, J. C. and Norris, R. H. (2000). Biological assessment of river quality: development of AUSRIVAS models and outputs. In Assessing the Biological Quality of Freshwaters: RIVPACS and other techniques (J. F. Wright, D. W. Sutcliffe and M. T. Furse, eds), pp. 125–142. Cumbria: Freshwater Biological Association. Sudaryanti, S. (1997). Bioassessment of the Brantas river. Department of Water Quality Management and Aquatic Ecology, Wageningen Agricultural University, Netherlands. Sudaryanti, S. (1999). Summary Report on Biodiversity of the Brantas Basin for the Study on Comprehensive Management Plan for the Water Resources of the Brantas River Basin in the Republic of Indonesia. Unpublished. Faculty of Fisheries, Brawijaya University, Malang, Indonesia. Sudaryanti, S., Trihadiningrum, Y., Rosmanida, Purwati, S.U., Supriyanta, H. and Yulianti, L. (1999). A trial of the Australian river bioassessment method in the Brantas River, East Java. In Proceedings of the International Conference on Water Quality and Waste Treatment, pp. 19–22 October, 1988, Lombok, Indonesia. Sudaryanti, S., Trihadiningrum, Y., Hart, B. T., Davies, P., Humphrey, C. and Norris, R. (2001). Application of the Australian River Bioassessment System (AUSRIVAS) in the Brantas River, East Java, Indonesia. Aquatic Ecology. In press. Susilo, B. W., Sudaryanti, S., Rachmandani, A., Dullah, Widodo, M. S. and Kusriani (1994). Reinvetaritation of indigenous fish in the Brantas river. Unpublished. Centre for Environmental Studies, Brawijaya University, Malang, Indonesia. Trihadiningrum, Y., Sudarjanti, S., Rosmanida, Purwati, S.U., Supriyanto, H. and Yuliyanti, L. (1999). The Brantas study: towards the development of bioassessment methods using macroinvertebrates in Indonesia. In Proceedings of the National Conference on River Bioassessment. Brawijaya University, 8–10 March, 1999, Malang, Indonesia. Wright, J. F. (1995). Development and use of a system for predicting the macro-invertebrate fauna in flowing waters. Australian Journal of Ecology 20, 181–197. Wright, J. F., Furse, M. T. and Armitage, P. D. (1993). RIVPACS: a technique for evaluating the biological quality of rivers in the UK. In European Water Pollution Control, 3, 15–25.