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P E Davies

Publications and source records attributed to P E Davies.

5 recordsLinked to original sources

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

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.

Animals↗

Physiological, anatomic and behavioural changes in the respiratory system of Salmo gairdneri Rich. On acute and chronic exposure to chlorothalonil.

1. Various changes in anatomical, physiological and behavioural aspects of the respiratory system of Salmo gairdneri on exposure to chlorothalonil (TCIN) were examined, along with the relationship between LC50 response and oxygen concentration. 2. The TCIN LC50 was significantly lower at 5 mg/l oxygen concentration than at 8 mg/l. 3. Haematocrit was depressed on exposure to TCIN, whereas exposure to pentachlorophenol and lindane raised the haematocrit. Muscle lactate was not elevated in acutely exposed fish. 4. Ventilatory frequency was raised above 30 micrograms/l TCIN. 5. Gills of fish exposed to 2.0 micrograms/l TCIN for 24 days had reduced lamellar diffusive capacity, primarily caused by an increase in blood barrier thickness.

Animals↗

Kidney biopsy.

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Biopsy↗

Temperature-dependent physiological response of Carcinus maenas exposed to copper.

The effect of temperature on the heart rate (fH) of Carcinus maenas exposed to a sublethal nominal concentration (0.5 mg l(-1)) of copper is reported. Adult, intermoult males (4 cm carapace width) were collected from Stavanger Fjord (Norway) in August (seawater TEMPERATURE=17 degrees C) and maintained in the laboratory (fed ad libitum) at 5, 15 and 25 degrees C for 7 days. Following this holding period, crabs were exposed to waterborne copper at the same temperature. After 3 days of exposure, individual fH was measured using the non-invasive Computer Aided Physiological MONitoring system (CAPMON) method. Copper-exposed individuals demonstrated significantly increased fH compared with controls at 5 and 25 degrees C (P<0.01). It is inferred that physiological function in C. maenas may be more vulnerable to copper contamination at seasonal temperature extremes (5 and 25 degrees C) than at the 'standard' test temperature (15 degrees C). Additionally, cardiac arrest observed at 5 degrees C is interpreted as a physiological response to limit copper uptake while the erratic fH in the 25 degrees C group reflected enhanced copper toxicity.

Animals↗