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Testing aquatic macroinvertebrate and plant techniques for the biological assessment of wetlands : a consideration of the effects of errors and implications for sampling designLing, Joanne Elizabeth, University of Western Sydney, College of Health and Science, School of Natural Sciences January 2006 (has links)
Rapid bioassessment techniques used for aquatic macroinvertebrate and plants in wetlands were tested in New South Wales, Australia. Wetlands surveyed ranged from coastal wetlands in the North and Central parts of the State, to tableland wetlands west of Sydney. Wetlands varied in dominant vegetation, hydrology, substrate and level of human impairment. Different options for sampling (mesh size, live-picking times, quadrat size, number of samples or quadrats) and analysis (taxonomic resolution, transformations, biotic indices, multivariate and univariate analyses) are compared to determine optimal sampling effort and evaluate the effects of errors or variability. Results show that, for wetlands of New South Wales, sampling procedures developed and tested in streams and other regions of Australia may not be the most efficient. Using the data from 21 wetlands in New South Wales, a number of analytical techniques were evaluated for the effects of errors. Results show that species-level multivariate analysis is more sensitive in detecting less obvious differences between wetlands (i.e., small effect sizes), while family-level analyses are more appropriate for large effect sizes. A modified waterplant index was developed that is simpler and has a wider application than the other Australian options available. Inherent problems in each index tested were addressed. The results show that the process of summarising a large amount of information into a single value will result in the loss of both information and variability between samples and this cumulative effect of error may effect the assessment of wetland condition. The practical outcome of this thesis is a set of standardised steps to assess wetland quality using biological assemblages. The results show that protocols and indices for rivers are not directly transferable to palustrine, vegetation dominated wetlands. I present protocols that are more appropriate to wetlands and recognise that each protocol would need to be adapted for each wetland type. Despite the need for flexible protocols, I promote the need for a standard approach to wetland sampling and the need for consideration of the effects of errors in sampling designs. This study highlights the need for more research on the response of specific stressors to wetlands flora and fauna. The results from this study also show that wetland macroinvertebrates and plant communities can be used as surrogates in multivariate analyses for detecting large differences between wetlands (wetland types) but that impact assessment requires more detailed investigations including species identification and careful consideration of the choice of reference and control sites. In conclusion I emphasise the need for scientific rigour in the use of biological indicators and consideration of the effects of errors and implications to sampling designs. / Doctor of Philosophy (PhD)
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Kinetics and mechanism of various iron transformations in natural waters at circumneutral pH.Pham, An Ninh, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2007 (has links)
In this thesis, the implementation and results of studies into the effect of pH on the kinetics of various iron transformations in natural waters are described. Specific studies include i) the oxidation of Fe(II) in the absence and presence of both model and natural organic ligands, ii) the complexation of Fe(III) by model organic compounds, and iii) the precipitation of Fe(III) through the use of both laboratory investigations of iron species and kinetic modeling. In the absence of organic ligands, oxidation of nanomolar concentrations of Fe(II) over the pH range 6.0 -- 8.0 is predominantly controlled by the reaction of Fe(II) with oxygen and with superoxide while the disproportionation of superoxide appears to be negligible. Oxidation of Fe(II) by hydrogen peroxide, back reduction of Fe(III) by superoxide and precipitation of Fe(III) have been shown to exert some influences at various stages of the oxidation at different pH and initial Fe(II) concentrations. In the presence of organic ligands, different effects on the Fe(II) oxidation kinetics is shown with different organic ligands, their initial concentrations and with varying pH. A detailed kinetic model is developed and shown to adequately describe the kinetics of Fe(II) oxidation in the absence and presence of various ligands over a range of concentrations and pH. The applicability of the previous oxidation models to describe the experimental data is assessed. Rate constants for formation of Fe(III) by a range of model organic compounds over the pH range 6.0 -- 9.5 are determined. Variation of rate constants for Fe(III) complexation by desferrioxamine B and ethylenediaminetetraacetate with varying pH is explained by an outer-sphere complexation model. The significant variation in rate constants of Fe(III) complexation by salicylate, 5-sulfosalicylate, citrate and 3,4-dihydroxylbenzoate with varying pH is possibly due to the presence of different complexes at different pH. The results of this study demonstrate that organic ligands from different sources may influence the speciation of iron in vastly different ways. The kinetics of Fe(III) precipitation are investigated in bicarbonate solutions over the pH range 6.0 -- 9.5. The rate of precipitation varies by nearly two orders of magnitude with a maximum rate constant at a pH of around 8.0. The results of the study support the existence of the dissolved neutral species Fe(OH)30 and suggests that it is the dominant precursor in Fe(III) polymerization and subsequent precipitation at circumneutral pH. Variation in the precipitation rate constant over the pH range considered is consistent with a mechanism in which the kinetics of iron precipitation are controlled by rates of water exchange in dissolved iron hydrolysis species.
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The Influence of Nutrients on Aquatic Primary Production and Food Webs in Subtropical Streams of South East Queensland, AustraliaSchmitt, Andrea V, n/a January 2005 (has links)
The increasing world population and with it the increased pressure on food production are likely to challenge the availability of quality fresh water resources in the near future. To compound the looming water crisis, caused by an increased demand for water available for agricultural production, the quality of our fresh water resources is also likely to suffer from the consequences of increased population pressure, i.e. urbanization of land and growth of industries, and food production, i.e. agricultural use of land. Moreton Bay, South East Queensland, Australia, is listed under the United Nations Convention on Wetlands and is also a declared Marine Park. The Moreton Bay area, however, is already one of the five fastest growing urban areas in the developed world. Prognoses about future population growth and urban and industrial development in the area, have hence given rise to growing concerns about the future water quality in this international environmentally important area. Therefore the aim of the current study was to investigate the fate of nutrients in freshwater streams in the Moreton Bay area in order to gain a better understanding of nutrient pathways in aquatic systems and assist in refining the National Water Quality Management Strategy to provide better management of our waterways. To achieve this, the effects of land use on water quality were determined at 22 study sites in the Brisbane River Catchment. Within the catchment five main types of land use were identified, including urban, rural residential, cropping, grazing and mixed types of land use. Water quality was sampled during three seasons: the pre-wet (October - November), wet (December - March) and dry (April - August) season. Nitrogen and phosphorus concentrations in ambient stream water varied significantly spatially, i.e. types of land use, and temporally, i.e. seasons. At some sites, during certain times of the year, nutrient concentrations were found to exceed the range recommended by the Australian Water Quality guidelines. Nutrient concentrations were particular high in urban areas, especially during the dry season. It was also found that the 15N signatures in aquatic plants, i.e epipelic algae, correlated strongly with in-stream nitrogen concentrations. The large variability of in-stream nutrient concentrations, and the related changes in nitrogen isotopic signatures in aquatic plants, made it obvious to suggest that changes in land use may significantly impact on water quality in the catchment. Other changes in land use, for example riparian vegetation clearing, are also commonly observed in areas under urban, industry and/or agricultural growth pressure. This is of particular concern, given riparian vegetation is important not only in controlling nutrient and other organic matter input into streams, but also in regulating light levels for in-stream primary production. Previously riparian zones have been shown to be a prime source of carbon and energy for aquatic food webs in some studies, whereas other studies suggested the main driver of food webs is in-stream primary production. The current study used stable isotope analysis track carbon and nitrogen pathways through aquatic systems and determine the primary source of carbon and energy in aquatic food webs. Despite large spatial and temporal variability of 13C, aquatic consumers were closely tracking the carbon isotope signatures of plants and it was suggested that epilithic and epipelic algae are the main contributors to the carbon and energy budget of aquatic consumers.In realizing this importance of algae in aquatic systems, the next step in this study was to examine the relative importance of light and nutrient availability to periphyton and the effects of changes of these variables on plant biomass and primary production. In an in-situ experiment the levels of light and nutrients available to periphyton, were altered. Although nutrients and light may have colimited standing crop of periphyton, other variables were clearly limited by light. Parallel to this experiment on periphyton, the nutrient availability to Vallisneria spp. was experimentally altered to investigate the effects of changes in nutrient availability and nutrient limitation on other aquatic plants. The biomass of this submerged macrophyte increased three-fold in nitrogen and phosphorus sufficient areas over nutrient limited treatments. The physiological response, i.e. changes in concentrations of amino acids, of periphyton to changes in environmental conditions was also investigated on a large scale, i.e. spatial and temporal variability of amino acids, and a local scale, i.e. amino acid changes in artificially altered light and nutrient availability. This response was of particular interest in this study, as it was previously shown that physiological changes in plants impact on the quality of plants as food for consumers. The physiological changes in aquatic plants could thus provide an important link between nutrient input into streams (e.g. from terrestrial sources), impacts on aquatic plants (e.g.. nutrient uptake and physiological responses in plants) and effects on aquatic consumers (e.g. changes in food quality of plants and therefore impacts on biomass, growth and overall health of aquatic consumers).
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Usefulness of Macroinvertebrates for In Situ Testing of Water QualityOswald, Louisa Jane, n/a January 2008 (has links)
For various reasons, existing methods for the assessment of aquatic pollution do not always
adequately address the way in which contaminants affect receiving environments and their
component ecosystems. The main advantage of biological assessment over the measurements
of physical and chemical aspects of water quality is that biota provide an integrated response
to all prevailing influences in their environment. Biological assessment protocols have been
developed for a range of test organisms, from bacteria to mammals using measurement from
molecular biomarkers to indicators at the population or community level of organisation.
Macroinvertebrates in particular have been popular for ecological assessment of habitat and
water quality because they are small and straight forward to sample and identify using
relatively simple and inexpensive equipment and readily available taxonomic keys.
However, various biological assessment techniques also have their limitations. Field-based
assessment of biological communities does not provide direct evidence to determine
underlying causal relationships, while laboratory or mesocosm toxicity tests are criticised for
their limited ability to extrapolate to natural field conditions. To help bridge the gap, this
thesis aims to investigate the efficacy of using caged macroinvertebrates in situ to assess the
ecological condition of aquatic environments, and whether a causal relationship can be
established when macroinvertebrates are deployed in situ at sites known to have impaired
water quality. Endpoints employed in this thesis include survival, measurements of
morphology (as a surrogate for growth) and condition and, for trials assessing sites that
receive mine drainage, the tissue concentration of certain trace metals.
Development of an in situ approach to water quality monitoring and assessment will
potentially provide methods for use by resource managers, community groups and aquatic
researchers that are less expensive and faster to run than existing methods and will
complement other approaches employed in the assessment of water quality.
In situ testing of water quality using macroinvertebrates requires the collection, handling,
caging, deployment and retrieval of test organisms at sites of suspected pollutant impact. As
such procedural factors may affect test organisms and potentially confound their responses, it
is important to consider and understand as many of these factors as possible. Aquatic
macroinvertebrates held in finer mesh cages had larger heads than in coarser mesh cages. This
was likely due to increased substrate available for growth of epilithon and periphyton on
which the caged organisms could graze. Caging density had no effect on amphipod mortality
over the trial period, however, individuals held at higher densities increased in size (as
indicated by longer dorsal lengths) more than those held at lower or intermediate densities.
Temporary storage of test organisms in laboratory aquaria may facilitate the collection of
abundances required for in situ trials, however, tanked individuals were smaller and had lower
biomasses than individuals collected and deployed immediately. While this is likely to result
from differences in feeding during the storage period, it is also possible that tank storage and
the ?double handling? deleteriously affected them, or reduced their tolerance.
The effects of transplanting macroinvertebrates between sites varied considerably depending
on the characteristics of "source" and "transplant" sites. Certain taxa suffered marked
mortality within 24 hours even at their source site, indicating an adverse effect of the caging
itself, or perhaps via the change in food, shelter or microclimate which could potentially
render them unsuitable as test organisms in caging studies. Other taxa did not differ in
survival or body size when relocated between sites, with some evidence of increased growth
at sites dissimilar from their source site. In general, organisms relocated to sites that are
"similar" to their source environment performed less well at the transplant site. However,
organisms transplanted to "dissimilar" sites were found to be bigger than those caged and
deployed back to the source site.
When employed to assess known pollution scenarios in and around Canberra,
macroinvertebrate responses were, in some instances, able to be linked to specific
environmental parameters or combinations thereof. In Case Study 1, findings varied in
relation to the response endpoint being examined, and between test species, although
concentrations of metals were significantly higher in tissue of macroinvertebrates deployed at
the impact site downstream of the abandoned Captains Flat mine and increased with time
exposed. In Case Study 2, freshwater shrimp suffered significant mortality within 24 hours of
deployment at the impact sites, with larger individuals more susceptible at sites receiving
urban stormwater runoff. While various biological effects were most closely correlated with
ammonia concentrations at the site, different body size endpoints were affected in opposite
ways. In Case Study 3, body size endpoints for one test organism varied consistently with
respect to site and time factors, but none of the changes could be linked to any of the
environmental data collected. Response variables for a different test species also indicated
significant effects arising from both deployment site and time, however, each endpoint
responded in a different way to the treatment factors, and aligned with different
combinations of environmental data.
In general, linking of macroinvertebrate responses with environmental data was difficult
because of the high variability in the environmental data. However, it was further complicated
by the mismatch in the level of replication between the two datasets. As a consequence of
this, the macroinvertebrate data had to be collapsed to a lower level for comparison with the
environmental data, resulting in a loss of natural variability and analytical power. Since only
the strongest treatment effects, which could be detected above the background "noise", were
detected and modelled against the environmental data, it is possible that other "cause" and
"effect" relationships may have been overlooked.
From these results, it is clear that many macroinvertebrate taxa are suitable for use as
bioindicators in in situ trials, but that criteria used for selection of test species should
definitely include more than just impact-sensitivity and abundance. However, there are
several aspects associated with the experimental set up of field-based protocols involving
caged macroinvertebrates that may limit their usefulness as a rapid and reliable bioassessment
tool, and need to be considered when designing and undertaking these kinds of trials. It is also
apparent that choice of endpoint can greatly influence conclusions, with detection of treatment
effects reported in this thesis varying greatly depending on which morphological endpoint
was examined.
This study clearly demonstrated that there may be significant difficulties in establishing
causal relationships between environmental data and biotic responses of macroinvertebrates
deployed under field conditions. However, it has also shown that deployment of caged
macroinvertebrates in situ may assist in the determination of biological effects arising from
impaired water quality, which can then serve as the basis for more focussed laboratory or
mesocosm studies in which environmental conditions can be more readily controlled or
monitored.
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A catchment approach to managing agricultural pesticides in the environment : a case study with the herbicide atrazinePopov, Vladislav H., University of Western Sydney, College of Science, Technology and Environment, School of Environment and Agriculture January 2005 (has links)
Surface water quality of the Liverpool Plains (NSW), a series of floodplains comprising the floodplain of the Mooki River, is poor despite the introduction of conservation tillage that has reduced soil erosion and, with it, the transport of sediment, nutrients and chemicals to streams.The aim of this thesis was to provide a basis for recommending the possible wider use of biofilters, by determining their effectiveness in reducing pollutant (mainly atrazine) transport at multiple scales in the Liverpool Plains, quantifying the importance of relevant processes, including the capacity of soil biofilters to degrade the retained pollutants, and evaluating the effect of pollutants on the biofilter vegetation. These objectives were explored in two sub-catchments within the Liverpool Plains, namely Big Jacks Creek and the Blackville.Soils are predominantly vertosols that crack deeply on drying, resulting in initially high infiltration rates on wetting and high water holding capacity. Field monitoring revealed that biofilters such as grassed waterways, natural grasslands or vegetated filter strips (VFS) positioned at multiple catchment scales can significantly reduce pollutant concentrations in runoff. The use of biofilters is discussed, along with other best management practices that will be needed to manage pesticide loads both at source and in the transport pathway. / Doctor of Philosophy (PhD)
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Indigenous communities and the co-management of natural resources : the case of New Zealand freshwater managementTipa, Gail, n/a January 2003 (has links)
The starting point for this study is a socially constructed problem: the progressive degradation of natural resources of significance to indigenous communities and the lack of effective participation by indigenous communities in their management. For many indigenous communities survival was traditionally dependent upon knowledge of natural resources and the ability to gather sustainability those resources from lands, waterbodies and the seas within tribal territories. Environmental sustainability and the long term wellbeing of indigenous communities were seen as one and the same thing. But following contact with exogenous groups, and until relatively recently, indigenous perspectives on environmental management were largely ignored. Dispute over ownership, access to management and use of natural resources have been sources of long standing grievance for indigenous communities throughout the world including Maori within New Zealand.
In the last decade co-management has been promoted as a means of ensuring the participation of indigenous communities in contemporary resource management. But what is meant by co-management has been less clear.
This thesis posits that of the four possible definitions of co-management - namely dual management, cooperative management, collagorative management and community based management - it is collaborative management that promises the greatest benefits for indigenous populations and the environment alike. An analytical framework is developed which acknowledges the theories brought to such collaboration by State agencies and Maori in New Zealand. A case example is then presented of the establishment of a collaborative management programme involving freshwater in the Taieri Catchment near Dunedin.
Experience of this case suggests that in addition to affirming progressively validated general principles governing collaborative environmental management, the requirement for trusted facilitators acting at the interface between State agency and indigenous groups is mandatory. It is concluded that the potential exists for the collaborative management of environmental resources by State and Maori in New Zealand but that the process has barely begun and requires investment in capacity building on the part of both parties.
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Factors influencing phytoplankton composition in Wingecarribee and Fitzroy Falls ReservoirsFurler, Wayne, n/a January 1990 (has links)
Wingecarribee and Fitzroy Falls Reservoirs are part of the Shoalhaven
system within the Sydney metropolitan water supply network and are both
shallow, well mixed, polymictic water bodies. After construction in 1973,
land use activities within the catchments changed from low intensity grazing
to more intensive practices such as dairying, particularly on the northern
foreshore of Wingecarribee Reservoir, and vegetable farming around Fitzroy
Falls Reservoir. The change in land use practice raised concerns about the
possible impact on water quality of the reservoirs. This study sought to
differentiate between the influence of catchment effects, inter-reservoir
transfers and seasonality to enable an assessment of long term trends in
water quality to be made.
Data collected on a monthly basis by the Water Board between October
1973 and December 1985 were assessed and representative or 'indicator'
variables for the different influences were selected. Classification of the
phytoplankton to create sample clusters followed by discriminant analysis of
the abiotic data were performed to rank the 'indicator' variables
The classification analyses indicated that time of sampling was more
important than site differences in determining clustering and that both
Wingecarribee and Fitzroy Falls Reservoirs were well mixed and similar. The
influence of chronological changes following the initial filling of the
reservoirs, seasonality and inter-reservoir transfers were detected in the
clustering patterns. Changes attributable to land use activities within the
catchments were not detected. The reduction in concentrations of variables
from high values following the initial filling of the reservoirs was the
main influence regulating clustering between 1974 to 1982 and the influence
of seasonality on clustering was most apparent during 1976 and 1978. The
assessment of the influence of inter-reservoir transfers was restricted
because of limited data.
Seasonal periodicities and ongoing changes in the phytoplankton and
physical and chemical data over the study period were assessed as a means of
interpreting and verifying the analysis results.
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Sedimentation in the Coorong lagoon, South Australia / by Raymond George Brown.Brown, Raymond George January 1965 (has links)
"September 1965." / Includes bibliographical references. / 223 leaves : ill. ; 30 cm. + maps in the end pocket / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Mineralogy, 1967
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Water Quality and Optical Properties of Swedish Lakes and Coastal Waters in Relation to Remote SensingStrömbeck, Niklas January 2001 (has links)
<p>Semi-analytical models for remote sensing of water quality parameters need to be parameterized with specific inherent optical properties. In this thesis, data on specific inherent optical properties of Swedish lakes and coastal waters is presented. Also, the problems of measuring in situ spectral backscattering are addressed. It is shown how measured specific inherent optical properties are used to parameterize semi-analytical bio-optical models. The models are then used to produce large synthetic data sets based on the distribution of water quality parameters, and from these data sets, band ratio or single band ratio algorithms for remote estimation of water quality parameters are constructed. A similar model was also used to calculate under water PAR from measured water quality parameters.</p><p>The specific inherent optical properties of Swedish lakes and coastal waters are very similar to earlier reported data from the oceanic environment. However, different relations of the water quality parameters will affect the inherent optical properties absorption and backscattering. The absorption spectra are dominated by yellow substance with terrestrial origin. Phytoplankton absorption is low, and account in general only for about 10 % of the total absorption in regions where phytoplankton pigments are active. The spectral backscattering is dominated by suspended particulate inorganic matter. Phytoplankton backscattering is almost negligible, except in cases where the phytoplankton community is dominated by highly scattering cyanobacteria. Experiences from remote sensing campaigns and modeling shows that remote chlorophyll estimation is most effective at longer wavelengths, where the absorption of yellow substance is low. However, modeling also predicts that large uncertainties have to be expected in the estimation of chlorophyll, both from variation in the specific phytoplankton absorption and from influences of other optically active water quality parameters.</p>
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Evaluation of bacterial community indicators of stream sanitary and ecological conditionBracken, Caragwen L. 08 September 2003 (has links)
The focus of this research was to develop bacterial community indicators of
stream sanitary and ecological condition. The first study compared substrate utilization
patterns between centrifuged and uncentrifuged split samples. We found a shift in the
relative proportion of each group of bacteria following centrifugation, with a marked
increased in the fecal coliform group and relatively fewer heterotrophic and total coliform
bacteria. Centrifuged samples consistently responded faster and oxidized more substrate
than did their uncentrifuged counterparts. Substrate utilization patterns of centrifuged
sub-samples from 19 sites showed better separation between Willamette Valley and
Cascade ecoregions than did the uncentrifuged sub-samples in ordination space. We
recommend developing microtiter plates with substrates specific types of environmental
stress. The second study determined the minimum volume of water needed and the
maximum time and temperature that bacteriological water samples captured on a
membrane filter can be held in guanidine isothiocyanate buffer (GITC) prior to DNA
extraction for community fingerprint analysis. We found 100 ml water samples yielded
more information than the 50 ml or the 250 ml water samples and observed a marked
decrease in information for samples that were held at room temperature for more than 24
hours. We concluded that 100 ml samples were optimal for bacterial community DNA
fingerprint analysis. Furthermore, we recommended transporting filtered water samples
held in GITC on ice and keeping the samples frozen until DNA is extracted for further
analysis. The third study addressed questions of sampling error and response variability
of two PCR-based indicators, bacterial community-level Terminal-Restriction Fragment
Length Polymorphisms and Bacteroidetes ruminant and human specific fecal source
tracking markers. We found the T-RPLP and Bacteroidetes markers to show very little
sampling error, and suggested collecting a single 1-liter water sample. A high turbidity
scenario resulting in higher fecal pollution and lower bacterial species richness explained
why decreased TRF richness was strongly associated with high fecal coliform density,
turbidity, and human Bacteroidetes detection. We propose that in times of increased
turbidity, a disturbance in the bacterial community occurs, reducing bacterial richness
and increasing a few types of stress-resistant fecal bacteria. / Graduation date: 2004
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