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  • 1
    Electronic Resource
    Electronic Resource
    An ecologically useful classification of mean and near-bed flows in streams and rivers (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 21 (1989), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. 1. Mean motion and near-bed flows in streams and rivers can be described using a classification derived from fairly simple field measurements. Our proposed classification is ecologically useful because it incorporates the combined effects of velocity, depth and substrate roughness to provide a means of quantifying the flow regimes occurring within the microhabitats of stream benthos.2. Mean motion is characterized by the Reynolds number and the Froude number. Both are easily calculated, and because they are dimensionless they provide a means of comparing flows at different sites.3. Five categories of near-bed flows (i.e. the flow microenvironments of stream benthos) are recognized. Flow may be hydraulically smooth or hydraulically rough and the latter category is subdivided further into: chaotic flow, wake interference flow, isolated roughness flow and skimming flow. Hydraulically smooth flows occur in sections of a river bed with fine sediments (e.g. sands, muds and clays). over flat sheets of bedrock, or in association with the flat blades of submerged macrophytes. Hydraulically rough flows occur where the substrate elements are larger (e. g. pebbles, cobbles and boulders) and are a function of substrate roughness and the depth of flow relative to the height of the roughness elements. Chaotic flows and wake interference flows predominate in riffles whilst isolated roughness flows and skimming flows are more likely to be a feature of runs.4. Conventional stream sampling methods (e.g. the Surber and box or cylinder samplers) may collect across several different flow microhabitats. Our classification should enable different flow microenvironments to be recognized and so sampled more appropriately which, in turn, may reduce apparent clumping and the wide confidence intervals of benthic population estimates. Because our classification identifies ‘patches’ within the flow regime associated with the stream bed it enables stream ecologists to generate testable hypotheses regarding the distribution and abundance of benthic species in response to flow.5. Our classification identifies spatial patterns in the flow regimes associated with the stream bed. Temporal patterns have not been identified: however, predictable changes in spatial patterns will resuh from temporal changes in stream discharge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1989.tb01365.x
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  • 2
    Electronic Resource
    Electronic Resource
    Manipulating the intensity of near-bed turbulence in rivers: effects on benthic invertebrates (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 42 (1999), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. Flow conditions were modified over patches of river bed in three rivers in south-western Australia to determine the effects of turbulence on benthic invertebrate communities.2. Artificial structures to increase downstream turbulence were developed in a laboratory flume. In the field, these increased turbulence intensity by 35% for a 20% reduction in velocity.3. Patches of gravel were placed in each river and turbulence-generating structures allocated randomly to half of these, creating treatment patches. An acoustic Doppler velocimeter was used to measure flow conditions over both treatment and control patches at several heights above the bed. After 6 weeks, the invertebrate fauna of the gravel patches were sampled to examine the response to modified flow conditions.4. The treatments increased relative turbulence intensity twofold for a reduction in velocity of between 3 and 5 cm s−1, but turbulence intensity was significantly higher in only one of the three rivers.5. There were no significant effects of increased relative turbulence intensity on any aspect of the invertebrate assemblage. This may be a result of the fairly small increase in relative turbulence intensity created during the experiment, the spatial scale of the manipulation or the types of stream community studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1999.00506.x
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  • 3
    Electronic Resource
    Electronic Resource
    AN APPARATUS FOR PHASE STUDIES BETWEEN 20° K. AND 300° K. (1963)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 55 (1963), S. 36-42 
    Details
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ie50647a007
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  • 4
    Electronic Resource
    Electronic Resource
    Dew and Bubble Isotherm Calculational Method for Binary System Phase and Volumetric Behavior (1964)
    s.l. : American Chemical Society
    Industrial and engineering chemistry 3 (1964), S. 8-14 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/i160009a002
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  • 5
    Electronic Resource
    Electronic Resource
    AusRivAS: using macroinvertebrates to assess ecological condition of rivers in Western Australia (1999)
    Oxford, UK : Blackwell Science, Ltd
    Freshwater biology 41 (1999), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. AusRivAS (Australian River Assessment Scheme) models were developed, using macroinvertebrates as indicators, to assess the ecological condition of rivers in Western Australia as part of an Australia-wide program. The models were based on data from 188 minimally disturbed reference sites and are similar to RIVPACS models used in Britain. The major habitats in the rivers (macrophyte, channel) were sampled separately and macroinvertebrates collected were identified to family level.2. Laboratory sorting of preserved macroinvertebrate samples recovered about 90% of families present when 150 animals were collected, whereas live picking in the field recovered only 76%.3. Reference sites clustered into five groups on the basis of macroinvertebrate families present. Using seven physical variables, a discriminant function allocated 73% of sites to the correct classification group. A discriminant function based on seven physical and two chemical variables allocated 81% of sites to the correct group. However, when the same reference sites were re-sampled the following year, the nine variable discriminant function misallocated more sites than the seven variable function, owing to annual fluctuations in water chemistry that were not accompanied by changes in fauna.4. In preliminary testing, the wet season channel model correctly assessed 80% of reference sites as undisturbed in the year subsequent to model building (10% of sites were expected to rate as disturbed because the 10th percentile was used as the threshold for disturbance). Nine sites from an independent data set, all thought to be disturbed, were assessed as such by the model. Results from twenty test sites, chosen because they represented a wide range of ecological condition, were less clear-cut. In its current state the model reliably distinguishes undisturbed and severely disturbed sites. Subtle impacts are either detected inconsistently or do not affect ecological condition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1999.00430.x
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  • 6
    Electronic Resource
    Electronic Resource
    Patterns of distribution of macroinvertebrate families in rivers of north-western Australia (1999)
    Oxford, UK : Blackwell Science, Ltd
    Freshwater biology 41 (1999), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. The northern half of Western Australia is a large, sparsely populated area with a climate that ranges from monsoonal in the Kimberley to arid in the Gascoyne and Pilbara regions. The aquatic invertebrate fauna is poorly known.2. Fifty-one sites located on 14 river systems were sampled three times between August 1994 and October 1995. A total of 90 taxa, most identified to family level, were collected. The fauna was dominated by insects, which constituted 74% of the total number of taxa collected.3. Major habitats at each site were sampled separately and sites with more habitats tended to have a richer fauna. All habitats showed significant differences in taxonomic richness between regions. Family richness decreased with increasing latitude, being highest in the Kimberley region and lowest in the Gascoyne.4. Despite the differences in taxon richness between regions, community composition of the aquatic invertebrate fauna at the family level did not differ greatly. Four major groups of sites were identified by cluster analysis, based on the invertebrate families present at each site, but differences between groups were small.5. Significant temporal variation in taxon richness was found in channel habitat but not the three other habitats sampled (riffle, macrophyte, pool-rocks). Community composition in channel habitat varied temporally among groups of sites identified by cluster analysis but the pattern was not consistent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1999.00432.x
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  • 7
    Electronic Resource
    Electronic Resource
    Forestry impacts and the vertical distribution of stream invertebrates in south-western Australia (1998)
    Oxford, UK : Blackwell Science Ltd
    Freshwater biology 40 (1998), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. Vertical distributions of invertebrates (〉 53 μm) were compared between two logged and two undisturbed headwater streams in south-western Australia. The abundance and composition of invertebrates from core samples (4 cm diameter, 30 cm depth) were determined at intervals of 0–1 cm, 1–5 cm, 5–15 cm and 15–30 cm.2. In addition to examining the effects of clearfell logging, this study provides the first description of the interstitial communities of Australian sandy streams. The interstitial fauna of the undisturbed streams were concentrated in the upper 5 cm of the bed and were numerically dominated by nematodes, a characteristic more typical of marine and lentic habitats than lotic systems.3. The invertebrate community structure was substantially altered in the logged streams, with fewer taxa collected than in undisturbed streams. Invertebrate densities in the logged and undisturbed streams did not differ in the upper 5 cm of the bed, but, below this, densities were significantly lower in the logged streams. Increased sedimentation did not appear to be responsible for the differences in community structure between logged and undisturbed streams.4. The impact of clearfell logging to the extent shown here has not previously been demonstrated in south-western Australia. As a consequence it is strongly recommended that sampling of the benthic meiofauna is included in future biomonitoring protocols for the sandy streams of this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1998.00337.x
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  • 8
    Electronic Resource
    Electronic Resource
    Seasonal variation in the macroinvertebrate fauna of wetlands of differing water regime and nutrient status on the Swan Coastal Plain, Western Australia (1995)
    Springer
    Hydrobiologia 299 (1995), S. 147-161 
    Details
    ISSN: 1573-5117
    Keywords: Macroinvertebrates ; wetlands ; seasonal ; nutrients ; Western Australia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Physicochemical attributes were measured and aquatic macroinvertebrates were collected from six wetlands near Perth, Western Australia at three weekly intervals over a 13 month period from August 1988 to September 1989. The six wetlands encompassed a range of depths, pH, concuctivities, nutrient concentrations and colours. Temporal changes in the macroinvertebrate communities appeared to be related to seasonal changes in the physical and chemical characteristics of the wetlands. Community composition differed more between the less enriched wetlands then the higly enriched wetlands where communities were generally similar. High species richness was associated with seasonal drying. High macro invertebrate abundance appeared to be associated with the presence of either green algal or cyanobacterial blooms in the enriched wetlands. The highest macroinvertebrate biomass was recorded in wetlands with both cyanobacterial blooms and abundant macrophytes present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017566
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  • 9
    Electronic Resource
    Electronic Resource
    The influence of sampling method on the classification of wetland macroinvertebrate communities (1993)
    Springer
    Hydrobiologia 257 (1993), S. 47-56 
    Details
    ISSN: 1573-5117
    Keywords: macroinvertebrates ; sampling methods ; wetlands ; classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Macroinvertebrate communities sampled by a corer, plankton net and sweep net from five wetlands on the Swan Coastal Plain were compared. The composition of the fauna collected in sweeps and tows was generally similar and differed from that collected in the cores. Cores caught fewer species than tows and sweeps at all wetlands and did not capture fast swimming hemipterans or less abundant taxa. The highest species richness was recorded in sweep samples in four out of the five wetlands. Classification (TWIN-SPAN) and ordination (SSH) of the samples collected in sweeps and tows gave good separation of the wetlands, whereas classification of core samples did not. Coring appeared to be the least suitable sampling method for describing the major components of the macroinvertebrate communities of these wetlands. Plankton tows were useful if the time available for sorting was limited as these samples were free of sediments and generally gave similar results to those obtained with sweeps. Sweeps appeared to be the most useful method for a large classification study as they collected more species and resulted in the best discrimination amongst wetlands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00013996
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  • 10
    Electronic Resource
    Electronic Resource
    Eutrophic waters of southwestern Australia (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 105-114 
    Details
    ISSN: 1573-0867
    Keywords: eutrophication ; phosphorus ; algae ; cyanobacteria ; seagrasses ; plankton ; benthic fauna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Water bodies in coastal areas of southwestern Australia are predisposed to eutrophication. The sandy soils of the catchments retain nutrients poorly, streamflow is highly seasonal, most freshwater wetlands are small and shallow, and the estuaries are poorly flushed. Nearshore waters lack the conventional upwelling of other coastal regions in these latitudes. Consequences include increased macroalgal growth and phytoplankton blooms, especially of cyanobacteria, and loss of seagrasses. Changes to fish and invertebrate populations result both from increased algal production and low oxygen concentrations. Algal toxins and outbreaks of botulism have caused waterbird casualties. Phosphorus is especially important in controlling plant biomass in freshwater wetlands and estuaries, and N in some wetlands and coastal embayments. In the examples reviewed here nutrients are derived mainly from fertilizer applications in catchments and rural industries, and from sewage and individual discharges to coastal waters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747580
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