Tesi sul tema "Constructed wetlands South Australia"

Bibliography: leaves 127-134. This thesis argues for the expansion of ecotourism in the Adelaide metropolitan Barker Inlet Wetlands, currently used for small scale ecotourism. Through analysing current literature and evaluating a range of ecotourism strategies, it demonstrates that the potential for and offers guidelines for ecotourism in the Barker Inlet Wetlands. Opprtunities for expansion lie primarily in environmental education, with a particular focus on Adelaide secondary schools.

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000?
Corrigenda pasted onto front end-paper. The CD contains Excel spreadsheets containing data collected. Bibliography: leaves 209-222.

Bibliography :leaves 158-171. A monitoring program, funded by the South Australian government (through the former MFP Development Corporation), was established to monitor the quality and quantity of storm water entering and leaving the wetland. This study formed part of the funded program. Simple regression models were developed; and will assist in the monitoring of performance of the wetland to alleviate the pollutant load into the Barker Inlet.

The phosphorus removal characteristics of several gravel-based constructed wetland systems (CWSs) in the treatment of secondary sewage effluent was studied.Investigations were conducted on water quality parameters (redox potential, pH, dissolved oxygen and temperature) which affect phosphorus adsorption to substrata.Laboratory phosphorus adsorption experiments on Richmond CWS gravel substrata, a gravel used in Griffith CWS trials and a locally available soil, Hawkesbury sandstone, involved ion-exchange experiments and calculation of Langmuir and Freundlich adsorption isotherms and column adsorption/desorption trials.Six steelworks by-products were investigated in laboratory studies, to determine their potential for use as phosphorus adsorbers in a CWS: granulated blast furnace slag(GBF), blast furnace slag(BF), steel slag(SS), fly ash(FA), bottom ash(BA) and coal wash(CW).The ability to adsorb phosphorus was then correlated to the chemical attributes of each substratum.Of the six steelworks by-products screened in laboratory-based studies as substrata for P removal in a CWS, BF and SS slags showed the most potential due to their high phosphorus adsorption capacity and useable matrix size.Further research is recommended to evaluate the sustainability of using slags for P removal (as well as other contaminants present in wastewater), using full scale CWSs, which should include an evaluation of any likely environmental impacts using leachability and toxicity studies.
Doctor of Philosophy (PhD)(Environmental Science)

The use of constructed wetlands and wet detention basins has proven to be highly effective in removing pollutants from industrial discharges and stormwater runoff throughout the world. This is attributed to design of the key treatment components in a constructed wetland, catchment source characteristics and climatic conditions. A disproportionate amount of research and monitoring effort has gone into constructed wetlands due to their cost effectiveness and ability to optimize multiple benefits. In Western Australia, several wetland monitoring studies on the role of constructed wetlands especially in Swan-Canning estuary have been done, but often do not address their design efficiencies in stormwater treatment. Two wetlands (Liege St and Tom Bateman wetland) constructed for nutrient stripping proximal to the Swan-Canning estuary have been monitored for two years. Liege St wetland was constructed to reduce the nutrients reaching the Canning River directly and improve the amenity value of the area. Similarly, Tom Bateman wetland was constructed to reduce nutrients of the Banister Creek catchment draining into the Canning River as well as for stormwater management and habitat use. Physicochemical and biological indicators were used to assess the nutrient stripping efficiency of the wetlands. In some cases, data from previous studies were used to determine the health and viability of the selected wetland sites. The limnological indicators used included; dissolved oxygen, pH, water temperature, electrical conductivity and nutrient levels. The biological included; bacteria, nutrients and chlorophyll in periphyton, macroinvertebrates and diatoms. Differences in the community structure of periphyton, macroinvertebrates and water quality were found from the inlet to the outlet in both Liege St and Tom Bateman wetlands.Despite the poor water quality, Liege St wetland exhibited significant nutrient removal efficiencies for TP while Tom Bateman wetland had very high removal efficiency for TN. The TP removal in Liege St wetland was attributed to the design of key treatment components which included a gross pollutant trap, concrete lined sedimentation pond, vegetated sumplands, weirs and clay lining for the wetland bed. In contrast, Tom Bateman wetland lacked the above key treatment components. Additionally, the wetland experienced short-circuiting especially during high flow periods. The high TN removal in Tom Bateman wetland was attributed to assimilation by plants and micro-organisms especially by the dense growth of Potamogeton crispus observed on the wetland floor and the non- biological transformation processes such as volatilisation, sorption and sedimentation. The poor water quality of the inflow in both wetlands was attributed to catchment characteristics which were not fully investigated in this study. In an attempt to improve the nutrient stripping function of Liege St and Tom Bateman wetland, changes to the wetland design and routine maintenance were suggested for Tom Bateman and Liege St wetland respectively. Also the use of the Swan-Canning Cleanup Programe (SCCP) water quality targets as opposed to the ANZECC trigger values in water quality assessments in constructed wetlands in the Swan-Canning estuary is suggested among others.

The use of constructed wetlands and wet detention basins has proven to be highly effective in removing pollutants from industrial discharges and stormwater runoff throughout the world. This is attributed to design of the key treatment components in a constructed wetland, catchment source characteristics and climatic conditions. A disproportionate amount of research and monitoring effort has gone into constructed wetlands due to their cost effectiveness and ability to optimize multiple benefits. In Western Australia, several wetland monitoring studies on the role of constructed wetlands especially in Swan-Canning estuary have been done, but often do not address their design efficiencies in stormwater treatment. Two wetlands (Liege St and Tom Bateman wetland) constructed for nutrient stripping proximal to the Swan-Canning estuary have been monitored for two years. Liege St wetland was constructed to reduce the nutrients reaching the Canning River directly and improve the amenity value of the area. Similarly, Tom Bateman wetland was constructed to reduce nutrients of the Banister Creek catchment draining into the Canning River as well as for stormwater management and habitat use. Physicochemical and biological indicators were used to assess the nutrient stripping efficiency of the wetlands. In some cases, data from previous studies were used to determine the health and viability of the selected wetland sites. The limnological indicators used included; dissolved oxygen, pH, water temperature, electrical conductivity and nutrient levels. The biological included; bacteria, nutrients and chlorophyll in periphyton, macroinvertebrates and diatoms. Differences in the community structure of periphyton, macroinvertebrates and water quality were found from the inlet to the outlet in both Liege St and Tom Bateman wetlands.
Despite the poor water quality, Liege St wetland exhibited significant nutrient removal efficiencies for TP while Tom Bateman wetland had very high removal efficiency for TN. The TP removal in Liege St wetland was attributed to the design of key treatment components which included a gross pollutant trap, concrete lined sedimentation pond, vegetated sumplands, weirs and clay lining for the wetland bed. In contrast, Tom Bateman wetland lacked the above key treatment components. Additionally, the wetland experienced short-circuiting especially during high flow periods. The high TN removal in Tom Bateman wetland was attributed to assimilation by plants and micro-organisms especially by the dense growth of Potamogeton crispus observed on the wetland floor and the non- biological transformation processes such as volatilisation, sorption and sedimentation. The poor water quality of the inflow in both wetlands was attributed to catchment characteristics which were not fully investigated in this study. In an attempt to improve the nutrient stripping function of Liege St and Tom Bateman wetland, changes to the wetland design and routine maintenance were suggested for Tom Bateman and Liege St wetland respectively. Also the use of the Swan-Canning Cleanup Programe (SCCP) water quality targets as opposed to the ANZECC trigger values in water quality assessments in constructed wetlands in the Swan-Canning estuary is suggested among others.

One of the major water quality issues affecting waterways is eutrophication. Controlling the input of nutrients from municipal wastewater treatment plants (WTP’s) is a significant step in reducing eutrophication. Tertiary wastewater treatment for water quality improvement in particular Biological Nutrient Removal (BNR) is often expensive to construct with high maintenance costs. Constructed wetlands (CWs) offer an alternative wastewater treatment and have been used successfully worldwide to treat various types of wastewater. This study investigated the effectiveness of the Oxley Creek horizontal subsurface flow (SSF) CW for tertiary municipal wastewater treatment and the suitability of four native macrophyte species, Baumea articulata, Carex fascicularis, Philydrum lanuginosum and Schoenoplectus mucronatus. The investigation consisted of four main components: 1) Plants: monitoring plant establishment, growth, impact of cropping, gravel size, nutrient content and storage for the four macrophyte species trialed; 2) Water quality - effluent treatment: monitoring water quality and quantity entering and leaving the wetland to determine wastewater treatment; 3) Organic matter: accumulation of organic carbon within the wetland cells for the different gravel sizes (5mm and 20mm) and 4) Mass balance: combining nutrient storage by macrophytes with wastewater nutrient removal to determine proportion of nutrient removal by plant uptake. The Oxley horizontal SSF CW is situated at the Oxley Creek WTP in Brisbane (South- East), Queensland, Australia which has a sub-tropical climate. The experimental design involved four different substrate treatments: Cell A new 5mm gravel, Cells B and C old 20mm gravel and Cell D old 5mm gravel. Cells B, C and D had been operational since 1995 whereas Cell A had been in use since 2000. The wetland received secondary treated effluent direct from the Oxley Creek WTP at an average flow rate of 8L/min with a median hydraulic loading rate (HLR) of 0.12m/day and a hydraulic retention time (HRT) of 2 to 3 days. Each cell consisted of three gravel sections (Section 1 to 3) separated by 1m wide open water sections. Gravel Sections 2 and 3 were planted out with the four macrophyte species in October 2000, Section 1 remained unplanted. Plant health and leaf height was monitored to assess plant establishment and growth. Investigations into plant establishment and growth demonstrated that Carex was most suitable. Carex achieved the highest maximum leaf height and was not affected by pests and disease unlike Schoenoplectus and Philydrum. Above ground biomass was cropped in May and August 2001, with biomass of cropped material measured on both occasions. Plant health and re-growth following cropping of above ground biomass in May and August 2001 demonstrated that cropping retarded regrowth of Schoenoplectus and Philydrum. Carex and Baumea recovered quickest following cropping, with Carex achieving leaf height prior to cropping within 6 months. Proportion of biomass contained above and below ground was measured by collecting biomass samples three times over 9 months and dividing into plant components (roots, rhizomes, leaves, flowers and stems). Investigations into the proportion of above and below ground components indicated that >80% of biomass is contained above ground. Therefore cropping above ground biomass would potentially remove a significant proportion of nutrient storage from the CW. The results indicated that the ideal time for cropping was in spring/summer when plants are flowering particularly for Philydrum, whose flowering stems comprised 40% of total plant biomass. Flowering stems of Philydrum could potentially have a commercial use as a cut flower. Nutrient content of the four species in each cell was measured for individual plant components when first planted and after three (summer) and six (autumn) months growth. This was combined with biomass data to quantify nutrient bioaccumulation (nitrogen and phosphorus) by the four species in each cell. In terms of ability to bioaccumulate nitrogen and phosphorus, measurements of nutrient content and storage indicated that all four species were suitable. Nutrient storage was highest for Baumea and Carex. However high nutrient content may make the macrophytes more susceptible to pest and disease attack as found in this study for Philydrum and Schoenoplectus. Nutrient storage was highest in Cell A (new 5mm gravel) as a result of higher biomass achieved in this cell. The cropping and nutrient storage experiments indicated that Carex was the most suitable species for use in SSF CWs. Carex achieved the highest nutrient storage and had the fastest regrowth following cropping. Organic carbon accumulation between gravel particles measured as the proportion of material lost at 500oC was determined for gravel samples collected from each section for all four cells at 10cm depth increments (0-10cm, 10-20cm and 20-30cm). Investigations into organic carbon accumulation within the gravel substrate showed that organic accumulation was higher in the planted sections particularly for cells that had previously been planted with Phragmites australis. Organic accumulation was highest in the top 20cm of the gravel, which can be attributed to litter fall and root material. The effect of gravel size on plant growth, biomass, root depth and organic accumulation was assessed throughout the study. Investigations indicated that gravel size did not appear to affect biomass, maximum root penetration, re-growth following cropping and organic accumulation. Water quality from the inlet and outlet of each cell was measured fortnightly over 12 months (May 2001 to May 2002). Water quantity (HLR) was measured weekly using tipping buckets located at the inlet and outlet of each cell. Water quality and quantity were combined to investigate the nutrient removal efficiency of the wetland. The Oxley wetland was highly effective in reduction of TSS (<2mg/L) and COD (<30mg/L). Principal TSS and COD removal mechanism was physical with the first gravel section acting as a filter removing the majority of particulate material. Average loading rates to the wetland were 7.1 kg/ha/d PO4-P, 14 kg/ha/d NH4-N and 5.4 kg/ha/d NOx-N. Average daily mass removal rates ranged from 7.3 kg/ha NH4-N in Cell D to 4.6 kg/ha in Cell C (i.e. 37%-22% removal efficiency respectively); 5.2 kg/ha NOx-N in Cell C to 1.3 kg/ha in Cell A (i.e. 75%-22% removal efficiency) and 0.8 kg/ha PO4-P in Cell A to 0.1 kg/ha in Cell C (i.e. 10%-1% removal efficiency). Removal efficiency was calculated on a loads basis. Insufficient retention times (2-3 days based on tracer study) and anaerobic conditions (<1mg/L) limited further nitrogen removal. Negligible phosphorus removal for all cells was attributed to short retention time and likelihood of phosphorus adsorption being close to capacity. Investigation into the proportion of nutrient removal attributed to plant uptake demonstrated that nutrient uptake and storage in plant biomass accounted for <12% TN and <5% TP. This research project has provided several useful outcomes that can assist in future guidelines for designing effective SSF CWs in the subtropics/tropics. Outcomes include the importance of maintaining an adequate water level during the initial establishment phase. Maximising effluent treatment by pre-treatment of wastewater prior to entering SSF CWs to enable ammonia to be converted to nitrate and ensuring adequate hydraulic retention time. Carex fascicularis was the most suitable species particularly where harvesting regimes are employed. Philydrum flowering stems could be used as a cut flower in the florist trade.

The issue of sustainability has greatest significance in the midst of unilateral bio-socioeconomic degradation resulting from intense and increasing societal pressures placed on the unified global ecology. In such an environment, sustainable development seeks to manage natural resources within a free market economy, aiming to meet the needs of today's population, and to protect and enhance current resource quality and abundance. In this light, techniques of integrated sustainable primary production and wastewater management are the subject matters of this applied research. There are many researchable issues which could be addressed within the subject matter. The first focus in the research scope was driven by the most severe sustainability issue facing Central Queensland (Australia) in 2000: the depletion and degradation of freshwater supplies. Central Queensland (CQ) is an arid sub-tropical region that has suffered from a marked reduction in rainfall and increase in temperature over the last 100 years, {Miles, 2004 #172}, and by the year 2000, conditions had been exacerbated by eight years of severe drought and warmer than average temperatures and resulted in widespread animal and crop failures due to freshwater shortages. Such a problem required a multi-faceted ecological, social, and economic approach. Hence, research centred on investigating the science of integrating regional water-related industries and agribusiness, and biodiverse ecosystems to achieve water and wastewater reuse applications, and associated eco-socioeconomic benefits. Specifically, this research investigates the integration of (a) electrical power station wastewater (b) barramundi culture, (c) red claw culture, (d) constructed wetlands (for water quality management and habitat creation), and (e) hydroponic flower culture. This research produced outcomes of integrated water and wastewater reuse and recycling, marketable agriproducts production (fish, crayfish, and flowers), water and wastewater reuse and conservation, wetland primary production, carbon dioxide sequestration, aquatic pollution control, and biodiversity creation and support. Successful design and management, experimental trialing and evaluation of system components and subjects, and the development of a knowledge base including static and dynamic system models, represent advances in respective research areas, and underpin the emerging discipline of integrated systems approaches to eco-socioeconomic development. Additionally, several gaps in the current body of knowledge regarding integrated systems were filled, and interactive management tools were developed. Apart from this study, the integration of technologies (as described above) has not, to this author's knowledge, been accomplished.

Thesis (Ph. D.)--University of Adelaide, Dept. of Geography, 1997.
"Conducted as a cross-institutional student between the University of Adelaide and the Australian National Universiity." Includes bibliographical references.

The development and local distribution of organic soils in Australia have been poorly documented. Within Western Australia, conditions conducive to the accumulation of organic matter are geographically restricted and generally occur in coastal and/or forested landscapes. An extensive system of wetlands with peal soils occurs in the Muir-Unicup region in the far south west of Western Australia. Bokarup Swamp, Kodjinup Swamp and Noobijup Lake are representative of the wetlands occurring in this region. They arc shallow (

Increased groundwater usage, rainfall decline and activities such as mining have resulted in the acidification of certain wetlands in the south-west of Western Australia. This study investigated the influence of pH, the factor most commonly associated with acidification, on the invertebrate and diatom community structure of 20 wetlands in the south-west region of Western Australia. Few studies in Western Australia have investigated both biotic groups, particularly in relation to pH. Consequently, this study examined the comparative sensitivity of the two biotic groups to pH in order to identify the most effective biotic tool for assessing the ecological impacts of pH decrease. The wetlands included in this study displayed a wide range of pH from acidic (pH < 6.5) to alkaline (pH > 7.5). Other environmental parameters were also variable. Separation of the wetlands into three pH groups; Group 1 – acidic, Group 2 – circumneutral and Group 3 – alkaline, demonstrated that the acidic Group 1 wetlands generally had higher electrical conductivity than the remaining groups. This was probably due to the association of many Group 1 sites with mining and acid sulphate soils. Seasonal trends in environmental variables across the three pH groups were mostly unclear although some trends were evident within the individual pH groups. The study showed that invertebrate community structure differed in response to pH. However, the results also demonstrated that invertebrate distribution patterns were influenced by other factors.Potential indicator species identified from the study included Macrothrix indistincta and Tanytarsus fuscithorax/semibarbitarsus which were abundant in acidic waters and Alona quadrangularis which was common in circumneutral sites. Taxa such as Calamoecia tasmanica subattenuata were common over a wider range of pH (acidic to circumneutral) but may still have potential to act as indicators of pH decline. Diatom community structure was also shown to be influenced by pH, with the variable identified as a major determinant of diatom distribution patterns. Nitzschia paleaeformis and Navicula aff. cari were generally recorded from acidic wetlands and are potentially useful as indicators of low pH conditions. Brachysira brebissonii and Frustulia magaliesmontana were also identified as species with the potential to indicate pH decline. In contrast, taxa including Gomphonema parvulum, Staurosira construens var. venter and Nitzschia palea were generally associated with moderate to high pH levels. A comparative study of the two biotic groups using multivariate analyses revealed that diatoms were more sensitive to pH than invertebrates. Further investigation with a larger number of environmental variables would be necessary to ascertain the other factors primarily influencing invertebrate community structure. Nonetheless, the findings imply that diatoms and invertebrates differ in their responsiveness to various environmental factors and may provide complementary information on the integrity of a system. Multivariate analyses on an expanded data-set of 40 sites found that pH accounted for the greatest amount of variation in the data and was conducive to the development of a diatom-based pH inference model.The strongest model was produced using weighted averaging (WA) with classical deshrinking. While the model displayed a high correlation coefficient, the prediction error was also relatively high, probably as a result of the comparatively small and heterogeneous data-set. Incorporation of the data into a larger training set would be likely to improve the predictive ability. Applications for the model include pH reconstructions or use in monitoring programs. The current study has shown that pH is an important variable influencing both invertebrate and diatom community structure in wetlands in the south-west of Western Australia. However, the greater sensitivity of diatoms to pH suggests that they would be the most effective tool for the biological monitoring of pH in wetlands threatened or impacted by acidification. An integrated monitoring program including both diatoms and invertebrates may provide additional information on the impacts of pH decline and the overall integrity of the systems and should be investigated further.

Increased groundwater usage, rainfall decline and activities such as mining have resulted in the acidification of certain wetlands in the south-west of Western Australia. This study investigated the influence of pH, the factor most commonly associated with acidification, on the invertebrate and diatom community structure of 20 wetlands in the south-west region of Western Australia. Few studies in Western Australia have investigated both biotic groups, particularly in relation to pH. Consequently, this study examined the comparative sensitivity of the two biotic groups to pH in order to identify the most effective biotic tool for assessing the ecological impacts of pH decrease. The wetlands included in this study displayed a wide range of pH from acidic (pH < 6.5) to alkaline (pH > 7.5). Other environmental parameters were also variable. Separation of the wetlands into three pH groups; Group 1 – acidic, Group 2 – circumneutral and Group 3 – alkaline, demonstrated that the acidic Group 1 wetlands generally had higher electrical conductivity than the remaining groups. This was probably due to the association of many Group 1 sites with mining and acid sulphate soils. Seasonal trends in environmental variables across the three pH groups were mostly unclear although some trends were evident within the individual pH groups. The study showed that invertebrate community structure differed in response to pH. However, the results also demonstrated that invertebrate distribution patterns were influenced by other factors.
Potential indicator species identified from the study included Macrothrix indistincta and Tanytarsus fuscithorax/semibarbitarsus which were abundant in acidic waters and Alona quadrangularis which was common in circumneutral sites. Taxa such as Calamoecia tasmanica subattenuata were common over a wider range of pH (acidic to circumneutral) but may still have potential to act as indicators of pH decline. Diatom community structure was also shown to be influenced by pH, with the variable identified as a major determinant of diatom distribution patterns. Nitzschia paleaeformis and Navicula aff. cari were generally recorded from acidic wetlands and are potentially useful as indicators of low pH conditions. Brachysira brebissonii and Frustulia magaliesmontana were also identified as species with the potential to indicate pH decline. In contrast, taxa including Gomphonema parvulum, Staurosira construens var. venter and Nitzschia palea were generally associated with moderate to high pH levels. A comparative study of the two biotic groups using multivariate analyses revealed that diatoms were more sensitive to pH than invertebrates. Further investigation with a larger number of environmental variables would be necessary to ascertain the other factors primarily influencing invertebrate community structure. Nonetheless, the findings imply that diatoms and invertebrates differ in their responsiveness to various environmental factors and may provide complementary information on the integrity of a system. Multivariate analyses on an expanded data-set of 40 sites found that pH accounted for the greatest amount of variation in the data and was conducive to the development of a diatom-based pH inference model.
The strongest model was produced using weighted averaging (WA) with classical deshrinking. While the model displayed a high correlation coefficient, the prediction error was also relatively high, probably as a result of the comparatively small and heterogeneous data-set. Incorporation of the data into a larger training set would be likely to improve the predictive ability. Applications for the model include pH reconstructions or use in monitoring programs. The current study has shown that pH is an important variable influencing both invertebrate and diatom community structure in wetlands in the south-west of Western Australia. However, the greater sensitivity of diatoms to pH suggests that they would be the most effective tool for the biological monitoring of pH in wetlands threatened or impacted by acidification. An integrated monitoring program including both diatoms and invertebrates may provide additional information on the impacts of pH decline and the overall integrity of the systems and should be investigated further.

Constructed wetlands (CWs) are being introduced in many parts of the world to treat wastewater. CWs offer several advantages over conventional treatment, most notably to save costs and energy. By contrast there are several limitations associated with the use of CWs, such as variability and unpredictability in treatment performance. However the literature focuses largely on the advantages of the CWs with little attention being given to the limitations and impacts on the receiving environment. In South Africa, there are a few studies concerned with the application and performance of CWs, but as yet there are no guidelines for the design and construction of these systems. The aim of this research is to determine the performance of three CWs situated on the periphery of Cape Town, Western Cape, with the intention of contributing to knowledge on the South African CWs performance in general. The research interest was to purposely shift attention to an analysis of the performance of CW systems that could be measured in-situ as opposed to laboratory-based studies where certain variables could be contained or controlled. In this study the focus is on determining the impact that these systems might have on the surrounding environment by analysing the impact from these CWs on surrounding or receiving water bodies. Samples of influent and effluent were collected from various points within the CW and from the surrounding water bodies every two weeks during the winter season when biological activity is least productive. Performance was determined by considering the mean percentage change from influent to effluent, the significance of the difference between influent and effluent and by comparing resultant effluent quality to the Department of Water Affairs' discharge standards. The results of the study indicate a range of performance both within and between systems, but overall the performance was poor, with the exception of NH3 (96%) and E. coli (see below) that was removed at one of the sites, namely, at De Goede Hoop. While PO43- was adsorbed, it was very low at all three sites; 3.8%, 7% and 20% at De Goede Hoop, Wolwedans and Babylonstoren respectively. Furthermore, DWA's effluent standards of 10 mg/l for PO4 3- could not be met at all the sites. Poor PO4 3- removal can be explained either by low O2 concentrations or the choice of substrate that was used in the constuction. When O2 concentrations are low, solubilisation of minerals and subsequent release of dissolved of phosphorus occurs. Mean E. coli removal percentages were considerably lower compared to other studies undertaken elsewhere. E. coli removal was 85% at De Goede Hoop, 39% at Wolwedans and 65% at Babylonstoren. In general, the results indicate that more research on CW systems is required to improve our understanding of these systems. A better understanding of these systems will lead to enhanced design and thus assist in improved treatment performance so as to reduce the impact of CWs on the environment.

This study takes as its focus the contrasting manner in which the Nyoongar indigenous people and the early European settlers utilised three wetland environments in southwest Australia over the century between 1829 and 1939. The thesis offers both an ecological and a landscape perspective to changes in the wetlands of Herdsman Lake, Lake Joondalup and Loch McNess. The chain of interconnecting linear lakes provides some of the largest permanent sources of fresh water masses on the Swan Coastal Plain. This thesis acknowledges the importance of the wetland system to the Nyoongar indigenous people. The aim of this research is to interpret the human intervention into the wetland ecosystems by using a methodology that combines cultural landscape, historical and biophysical concepts as guiding themes. Assisted by historical maps and field observations, this study offers an ecological perspective on the wetlands, depicting changes in the human footprint on its landscape, and mapping the changes since the indigenous people’s sustainable ecology and guardianship were removed. These data can be used and compared with current information to gain insights into how and why modification to these wetlands occurred. An emphasis is on the impact of human settlement and land use on natural systems. In the colonial period wetlands were not generally viewed as visually pleasing; they were perceived as alien and hostile environments. Settlers saw the land as an economic commodity to be exploited in a money economy. Thus the effects of a sequence of occupances and their transformation of environments as traditional Aboriginal resource use gave way to early European settlement, which brought about an evolution and cultural change in the wetland ecosystems, and attitudes towards them.

The objective of this project was to determine if Galaxiella nigrostriata populations could belong to a metapopulation. Metapopulation theory describes how multiple populations with occasional connectivity are a ‘population of populations’. Some populations’ habitats have optimal conditions (source habitats), others experience regular extinctions (sink habitats). Connectivity allows repopulation of extinct or uninhabited habitats. Galaxiella nigrostriata occurred randomly in 11 seasonal wetlands in the Kemerton wetland complex in south-west Western Australia over a 16 year period. The wetlands did not appear to be connected. Around 70% of wetlands on the Swan Coastal Plain in south-west WA have been filled or degraded since European settlement around 180 years ago. Of those, seasonal wetlands are at most risk from degradation. Galaxiella nigrostriata mainly live in seasonal wetlands between Augusta and Albany and in three remnant populations on the Swan Coastal Plain. They are small freshwater fish (length), aestivate in moist wetland sediments when wetlands dry and live for about one year. Seasonal wetlands and G. nigrostriata are threatened by nutrient enrichment, salinity, introduced fish, landscape modification and changes to hydroperiod by groundwater abstraction and declining rainfall. Inundated wetlands that previously contained G. nigrostriata, and wetlands where they had not been recorded, were sampled throughout south-west WA. Fish and crayfish abundance was surveyed and water samples analysed on site and in a laboratory. Physical characteristics of each wetland and surrounding landscape were also recorded. Information about wetlands was analysed to determine if physico-chemical characteristics accounted for G. nigrostriata abundance or distribution between wetlands. Lentocorrals were then established in two Kemerton wetlands prior to inundation. They were sampled following inundation to determine how and where within a wetland G. nigrostriata entered the sediment to aestivate. Aestivation was examined to determine whether any physical features may be lacking which could inhibit population persistence. Galaxiella nigrostriata specimens from each population had morphological measurements and counts taken prior to tissue being removed for genetic analyses. Two mitochondrial DNA markers were used to investigate divergence and connectivity within and between populations and catchments. Most wetlands were small (mean 0.6 ha), had tannin-stained water and 41% vegetation cover. All wetlands exceeded guideline values for Fe and Zn and those near agricultural land exceeded guideline values for TN and TP. However, no physico-chemical water properties or habitat features impeded G. nigrostriata abundance or distribution between wetlands. Additionally, it was thought there may be a commensal relationship between G. nigrostriata and burrowing crayfish, with G. nigrostriata using burrows to enter the sediment. No relationship was found between G. nigrostriata, crayfish or their burrows, indicating an alternative way for them to enter the sediment. Genetic research and examination of wetland positions in the landscape confirmed G. nigrostriata populations (particularly Kemerton) are part of metapopulation. This research showed populations between catchments had not connected for thousands of years but populations in wetland complexes had recent connectivity. Management of wetlands requires investigation and monitoring of nearby wetlands which may be part of a metapopulation, and may affect population longevity of all wetlands.

Intertidal wetland habitats in southeastern Australia have changed significantly during the past sixty years. Mangrove habitats have expanded both seawards and landwards, the latter being at the expense of saltmarsh habitats. This relatively common phenomenon is generally suggested to be an outcome of sea-level rise. Several factors potentially responsible for this change are examined, including changes in mean sealevel during the past 50 to 100 years, changes in climate, population growth, catchment landuse, and estuary type. A protocol for mapping estuarine habitats was developed and implemented, incorporating the application of geographic information systems. Spatial and temporal coastal wetland habitat changes at nine sites along the New South Wales coast are illustrated. These habitat dynamics were shown to not correlate between sites. The results demonstrate that sea-level rise in this region cannot solely account for the extent of change during the past sixty years. With the exception of one site (Careel Bay), there have been no correlations between contemporary mean sea-level rise and mangrove incursion of the saltmarsh habitats at the study sites, or with rainfall patterns, at the scale of observation in this study, which was largely decadal. The only correlations determined during this study have been between population growth and coastal wetland habitat dynamics in some sites. In spite of saltmarsh habitat loss being a regional phenomenon, local factors appear to have a profound bearing on the rates of change. Neither contemporary mean sea-level rise, rainfall patterns, estuary type, catchment landuse, catchment natural cover nor population pressure can account solely for the patterns in the spatial and temporal dynamics of the coastal wetlands of New South Wales. It seems apparent that regional factors create preconditions favourable for mangrove incursion, but that localised conditions have been responsible for the extent of these incursions from site to site. That is, despite higher sea-level and greater rainfall, the extent of change has been determined by the unique characteristics of each site. The results have important implications for current estuary management practices in the state of New South Wales. The lack of spatial and temporal trends in coastal wetland habitat dynamics point to the need for management to be conducted on a localised, rather than regional scale. Additionally, anthropogenic influences must be carefully managed, since the extent of mangrove habitat expansion into saltmarsh areas is unlikely to be a natural occurrence.

Coastal wetlands are dynamic ecosystems that are highly susceptible to change due to natural and human factors. The study area, located within the Native Dog Creek sub-catchment of the Logan River - which drains into Moreton Bay, south east Queensland - holds a detailed history of environmental change spanning most of the Holocene epoch. This history is preserved in the estuarine sedimentary record and is a valuable indicator of natural environmental change. More recently, human-induced changes within the study area have been superimposed on the natural process of environmental change. In order to develop a conceptual bio-geomorphic model of the coastal wetlands of Native Dog Creek, this thesis examined - on an integrated catchment basis - the evolution and connectivity of four coastal wetland community types (Melaleuca, Casuarina, saltmarsh and mangroves). The research consisted of four discrete studies within the study area: a geomorphic investigation that provided a framework for understanding how the wetlands evolved during the Holocene epoch; an acid sulfate soil (ASS) study that surveyed the distribution and concentration of sulfides; a palynological study that examined the natural directions of ecosystem change; and an investigation of the impact of specific human activities on these ecosystems. Detailed stratigraphic modelling found that the Logan River system (and its Native Dog Creek sub-catchment) has evolved from an infilling estuary since the peak of the Holocene transgression 6500 years before present. Recognition of the major controls that influenced geomorphic coastal development during the Holocene, provided important insights into the distribution and genesis of estuarine pyritic sediments which strongly influence the soils within the study area. In general, the estuarine central basin and fluvial delta sediments posed the greatest risk to the environment from acidification if disturbed. The major focus of the ASS study was to survey the distribution of ASS and to identify other areas most vulnerable to acidification. A predictive approach that combined chemical and stratigraphic analysis was used. Results showed that these areas are intrinsically related to their environment of deposition. The study found, for example, that the alternation of excessively wet and dry conditions - combined with high organic carbon levels and variations in microtopography - provided ideal conditions for the re-formation of pyrite in the stream channel within the Melaleuca wetlands. The palaeo-environmental study reconstructed the evolution of Holocene coastal wetland vegetation during the marine transgression and subsequent shoreline progradation. Pollen records from the four representative wetland communities (previously mentioned) were examined. The results found the mid-late Holocene vegetation history was controlled by the development of geomorphic features that have affected freshwater input, drainage and salinity. In response to the progradation of the shoreline after sea level stabilised, changes in fossil pollen from mangroves and saltmarsh taxa during the early-mid Holocene, to freshwater taxa during the late Holocene, are estimated to have taken 800 years. Thus, pollen analysis when used in combination with stratigraphic modelling, provided an important point of reference for rates of natural ecological change in response to evolutionary changes to the physical environment. The wetlands within the study area have suffered varying degrees of disturbance since European settlement in the 1820s. The most significant changes occurred during early European settlement, when vast areas of coastal lowlands were cleared for timber, sheep and cattle grazing and for agricultural purposes. A second period of change occurred from 1989 to 1995, when the Melaleuca community suffered dieback in response to hydrological modifications to Native Dog Creek for the development of a golf course. Results indicate that human-induced changes over the past 170 years have occurred at a rate far beyond the ability of the natural ecosystem to adapt or move to a more ecologically sustainable state, at least in the short-term. Hence the current environment is experiencing degradation through both decline in health and loss of indigenous species. The development of a conceptual bio-geomorphic model was based on the integration of results from all four studies, in an effort to provide a holistic understanding of the coastal wetland environment and of the impact of human-induced changes upon that environment. If these vulnerable ecosystems are to be maintained, successful and sustainable coastal management strategies must rely on a sound scientific understanding of the response of a coastal ecosystem to both human and environmental changes.

"Figures, tables and the appendices appear in the volume II".
Bibliography: leaves 130-152.
2 v. (152 leaves, [5] leaves of plates; [75] leaves) : ill. (some col.), col. maps ; 30 cm.
Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 2001

Provides insight into the pollutant removal ability of a primary pond in the Barker Inlet Wetland System, one of the largest constructed wetlands in the world. Results show that storm size influences pollutant removal, however significant removal was acheived across a wide range of flow conditions.
Thesis (M.Eng.Sc.) -- University of Adelaide, Dept. of Civil and Environmental Engineering, 2000?

Includes list of publications issued during the candidature.
Bibliography: leaves 176-197.
iii, ix, 197, [22] leaves : ill., maps ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Phosphorus retention was measured in five pilot-scaled constructed wetlands with different configurations in terms of macrophyte species and substrates in order to evaluate the phosphorus removal efficiency of water plants and substrates in experimental ponds; assess the contribution of macrophytes to phosphorus removal through direct uptake, modification of water chemistry and impacts on the phosphorus adsorption characteristics of substrate; and, contribute to the optimal design and operation of constructed wetlands for the treatment of agricultural drainage water.
Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002?

Includes list of publications issued during the candidature.
Bibliography: leaves 176-197.
iii, ix, 197, [22] leaves : ill., maps ; 30 cm.
Phosphorus retention was measured in five pilot-scaled constructed wetlands with different configurations in terms of macrophyte species and substrates in order to evaluate the phosphorus removal efficiency of water plants and substrates in experimental ponds; assess the contribution of macrophytes to phosphorus removal through direct uptake, modification of water chemistry and impacts on the phosphorus adsorption characteristics of substrate; and, contribute to the optimal design and operation of constructed wetlands for the treatment of agricultural drainage water.
Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002?

The quantity of stormwater runoff from the city of Adelaide almost matches the demand for drinking water. It therefore becomes increasingly important as an alternative source for water supply. This research focused at the Parafield Stormwater Harvesting Facility near Adelaide in order to better understand: (1) nutrient dynamics between the water column, sediments and plant community, (2) allochthonous and autochthonous sources of nutrients and (3) nutrient retention capacity of the reed bed. A weekly monitoring programme for the physical and chemical parameters of the water column, sediment and plant community was carried out over three years for specific locations within the reed bed. Ordination and clustering of the time series data revealed distinctive seasonal and spatial nutrient patterns. The concentrations for total nitrogen (TN) showed high concentrations for the summer period (1.04 to 1.86 mg/L) and low concentration for the winter season (0.25 to 0.46 mg/L). For the other nitrogen fractions in form of nitrate (NO₃⁻) and ammonium (NH₄⁺) the seasonal patterns were different to that of TN. In NO₃⁻ the concentrations were high during the summer and winter seasons and NH₄⁺ showed high concentration during the spring. The seasonality for total phosphorus (TP) showed high concentration for the spring period (0.049 to 0.163 mg/L) and low concentration for the other seasons (0.01 to 0.019 mg/L). A similar pattern has been observed for phosphate (PO₄³ ⁻) as well. The dissolved organic carbon (DOC) concentrations showed high concentrations during the summer period (21.36 to 31.64 mg/L) and low concentration during the winter seasons (5.48 to 7.14 mg/L). The seasonal pattern for the nutrient contents of the plant community showed highest concentrations during summer (5.5 to 34.2 gTN/kg) and lowest concentrations in winter (0.2 to 7.7 gTN/kg). Nutrient concentrations in the sediments were highest during the non-growing seasons (autumn and winter). This result indicated that the function of sediments changes seasonally from being a sink during the non-growing season by accumulating both allochthonous and autochthonous nutrients in the rainy season, and becoming a source during the growing seasons due to nutrient release from anaerobic sediments supporting the growth of the macrophyte community. Overall the function of sediment in reed bed pond of the Stormwater Harvesting Facility was to be a source of nutrients and therefore no accumulation of nutrients occurred during the study period. The research has demonstrated that the reed bed currently performs as a reasonable nutrient retention system with following nutrient removal rates: 0.85 mg TN /m²/day, 0.79 mg NO₃⁻ /m²/day, 0.28 mg NH₄⁺/m²/day, 0.05 mg TP /m²/day, 0.04 mg PO₄³ ⁻ /m²/day, and 5.75 mg DOC /m²/day. Seasonal difference in the water retention time showed that the for most of the nutrients the removal performance was most effective during autumn and winter with the exception of the removal performance of P forms, which most effective during spring and summer. For TN, NO₃⁻ and DOC the RE was most efficient at a residence time > 15days, for TP and PO₄³ ⁻ it is 5-10 days and for NH₄⁺ it is <;5days. Time–series modelling of the monitoring data resulted in rule-based prediction models for the different nutrients. Sensitivity analyses of the models revealed key driving variables for the nutrient dynamics of the reed bed. The prediction results revealed that the DO was the key driving variable influencing the nutrient concentrations in the water column and therefore to improve the water quality of the treatment water DO levels have to maintained above the threshold of 4 mg/L. Beside DO other key driving variables were turbidity, ORP and the nutrient levels from the previous site. Therefore the control of these parameters would be the start to develop a management plan for best-practice management in terms of water quality at the Parafield Stormwater Harvesting Facility.
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2010

The quantity of stormwater runoff from the city of Adelaide almost matches the demand for drinking water. It therefore becomes increasingly important as an alternative source for water supply. This research focused at the Parafield Stormwater Harvesting Facility near Adelaide in order to better understand: (1) nutrient dynamics between the water column, sediments and plant community, (2) allochthonous and autochthonous sources of nutrients and (3) nutrient retention capacity of the reed bed. A weekly monitoring programme for the physical and chemical parameters of the water column, sediment and plant community was carried out over three years for specific locations within the reed bed. Ordination and clustering of the time series data revealed distinctive seasonal and spatial nutrient patterns. The concentrations for total nitrogen (TN) showed high concentrations for the summer period (1.04 to 1.86 mg/L) and low concentration for the winter season (0.25 to 0.46 mg/L). For the other nitrogen fractions in form of nitrate (NO₃⁻) and ammonium (NH₄⁺) the seasonal patterns were different to that of TN. In NO₃⁻ the concentrations were high during the summer and winter seasons and NH₄⁺ showed high concentration during the spring. The seasonality for total phosphorus (TP) showed high concentration for the spring period (0.049 to 0.163 mg/L) and low concentration for the other seasons (0.01 to 0.019 mg/L). A similar pattern has been observed for phosphate (PO₄³ ⁻) as well. The dissolved organic carbon (DOC) concentrations showed high concentrations during the summer period (21.36 to 31.64 mg/L) and low concentration during the winter seasons (5.48 to 7.14 mg/L). The seasonal pattern for the nutrient contents of the plant community showed highest concentrations during summer (5.5 to 34.2 gTN/kg) and lowest concentrations in winter (0.2 to 7.7 gTN/kg). Nutrient concentrations in the sediments were highest during the non-growing seasons (autumn and winter). This result indicated that the function of sediments changes seasonally from being a sink during the non-growing season by accumulating both allochthonous and autochthonous nutrients in the rainy season, and becoming a source during the growing seasons due to nutrient release from anaerobic sediments supporting the growth of the macrophyte community. Overall the function of sediment in reed bed pond of the Stormwater Harvesting Facility was to be a source of nutrients and therefore no accumulation of nutrients occurred during the study period. The research has demonstrated that the reed bed currently performs as a reasonable nutrient retention system with following nutrient removal rates: 0.85 mg TN /m²/day, 0.79 mg NO₃⁻ /m²/day, 0.28 mg NH₄⁺/m²/day, 0.05 mg TP /m²/day, 0.04 mg PO₄³ ⁻ /m²/day, and 5.75 mg DOC /m²/day. Seasonal difference in the water retention time showed that the for most of the nutrients the removal performance was most effective during autumn and winter with the exception of the removal performance of P forms, which most effective during spring and summer. For TN, NO₃⁻ and DOC the RE was most efficient at a residence time > 15days, for TP and PO₄³ ⁻ it is 5-10 days and for NH₄⁺ it is <;5days. Time–series modelling of the monitoring data resulted in rule-based prediction models for the different nutrients. Sensitivity analyses of the models revealed key driving variables for the nutrient dynamics of the reed bed. The prediction results revealed that the DO was the key driving variable influencing the nutrient concentrations in the water column and therefore to improve the water quality of the treatment water DO levels have to maintained above the threshold of 4 mg/L. Beside DO other key driving variables were turbidity, ORP and the nutrient levels from the previous site. Therefore the control of these parameters would be the start to develop a management plan for best-practice management in terms of water quality at the Parafield Stormwater Harvesting Facility.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2010

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library.
"The Lower Murray dairy swamps were once part of a series of freshwater wetlands stretching along the Murray to the Cooring. Of the original 5700 hectares of wetlands only 500 hectares remain today. While the dairy industry that has developed on the swamp has considerable commercial value, it has destroyed the natural water filtration function that the wetlands provided. The industry also causes high levels of dairly effluent to enter the River Murray, contributing to blue-green algae outbreaks and associated economic losses for the local tourism industry. This thesis provides valuable cost-benefit results on a set of three mutually exclusive land use and management options for dealing with the joint problems of water filtration and blue-green algae. The most important options examined involve the return of this area to wetlands for water filtration rather continuing to use it for dairy farming." --p. ix.
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Thesis (Ph.D.) -- University of Adelaide, School of Economics, 2007

"The Lower Murray dairy swamps were once part of a series of freshwater wetlands stretching along the Murray to the Cooring. Of the original 5700 hectares of wetlands only 500 hectares remain today. While the dairy industry that has developed on the swamp has considerable commercial value, it has destroyed the natural water filtration function that the wetlands provided. The industry also causes high levels of dairly effluent to enter the River Murray, contributing to blue-green algae outbreaks and associated economic losses for the local tourism industry. This thesis provides valuable cost-benefit results on a set of three mutually exclusive land use and management options for dealing with the joint problems of water filtration and blue-green algae. The most important options examined involve the return of this area to wetlands for water filtration rather continuing to use it for dairy farming." --p. ix.
Thesis (Ph.D.) -- University of Adelaide, School of Economics, 2007

Includes bibliography.
2 v. : ill., maps ; 30 cm.
This thesis analyses the aquatic macrophyte vegetation of remnant wetlands in the South East of South Australia and of Bool Lagoon in particular. The study describes the diversity of aquatic vegetation in 11 remnant and ephemeral wetlands in the South East using a multivariate approach of classification and ordination of vegetation quadrats. The second section of the study characterises the seasonal pattern of fluctuation through a numerical description of water regime. The third section is a consideration of the population demography of Typha domingensis and Phragmites australis in relation to flooding frequency at Bool Lagoon. The final section of the study considers the influence of flooding frequency on the distribution of some important components of the vegetation of Bool Lagoon.
Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1997

The Upper South East (USE) region of South Australia covers over 1M ha and is the largest area affected by dryland salinity in South Australia. In 1999, it was estimated that 40% of the region was affected by salinity. To mitigate the threat of flooding and secondary salinisation, an extensive network of drains has recently been constructed. Whilst these drains may have a positive effect on the agricultural land, the impacts they will have on the hundreds of wetlands in the region is as yet, unknown. It is likely that the hydrologic regimes the wetlands are exposed to will be highly modified and the quality of the water that supplies them will be greatly affected by high salinity levels. This work examined the impact of these landscape scale changes on wetlands in the South East region of South Australia and investigated ways in which water from the drainage system might be used for ecological benefit in wetlands. The aims were to: • determine whether there have been changes in species composition that can be linked to changes in the salinity and hydrology regimes experienced in the wetlands and to gain a better understanding of the processes and mechanisms that drive the change in species composition and cause salt to accumulate in wetlands via the development of a conceptual model; • produce curves predicting the probability of occurrence in relation to salinity for species common in wetlands in the South East of South Australia; • investigate the effects of an increase in salinity with decreasing water depth as a result of evapoconcentration on the growth and survival of three common freshwater macrophytes, and to determine the consequences of longterm exposure to elevated salinity conditions; • assess the impact of a pulsed discharge of saline drainage water of varying concentrations and durations on key wetland species in an effort to determine how to make best use of the scarce water resources in the region and; and • assess the combined effects of salinity and hydrology on the seed banks of wetlands that have experienced drought and elevated salinity conditions. The results of vegetation surveys conducted pre-2000 and post-2000, indicate an overall change in species composition; species requiring fresh conditions are rarer or not recorded and are replaced by species preferring more saline conditions. This change is accompanied by a shift from fresher to saltier conditions and from wetter to drier conditions. Data from groundwater observation bores coupled with flow volumes in the local watercourses supports the process of salt accumulation in wetlands described in the conceptual model. The curves predicting the probability of occurrence in relation to salinity display a wide range in tolerances across the 15 species for which they were constructed, and highlight the variance due to between wetland differences. These curves, used in combination with knowledge gained from other studies will enable salinity thresholds to be set for many of the common species found in the South East region. Employing these thresholds to drain operation will allow wetlands to be managed in a way that will promote the occurrence of target species. The study on evapoconcentration effects showed that the percentage of biomass allocated to below ground structures was > 95, > 90, > 75 and > 80% for adult and juvenile T. procerum, and for B. arthrophylla and B. medianus respectively, across all salinity treatments suggesting that long term exposure to elevated salinity conditions results in a large investment in below ground biomass by all species. This study also indicated that the initial lifestage at time of exposure to the salinity regimes had a significant effect on the final dry weights of the T. procerum plants. The differences in the dry weights and leaf length and number were greatest between adults and juveniles in the lower salinity treatments (1500 and 6250 μS cm⁻¹), with the adults having much larger weights and measures. At higher salinities (12500 and 18750 μS cm⁻¹), there were no differences. Salinities refer to the salinity of the surface water, not soil salinity. For the plants tested in the pulse salinity regime experiment, the immediate effect of high salinity environments on non-halophytic plants was not detectable after three to six weeks of exposure, but the short term impact of the pulse did affect the ability of submerged plants to recover. The seed bank trial showed that the previous drought and salinity conditions experienced by a wetland did affect the seed bank however the water and salinity regime imposed mitigated these impacts. The study provides evidence that extended periods of drought conditions may lead to a seed bank which has a reduced abundance of seeds and repeated exposure to high salinity changes the species composition of the seed bank and reduces the overall diversity. Our knowledge of wetland plants, habitats, individual wetlands and their pattern in the landscape enables interpretation of how wetland plants have changed and will continue to change in the landscape. The challenge is to use, and build on this knowledge to predict what future wetland landscapes might look like under different management or development scenarios in the USE and to decide what is sustainable.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences and School of Civil, Environmental and Mining Engineering, 2012

Most of the lower River Murray and its floodplain wetlands are impacted upon by degradation caused by river regulation. Increasingly the restoration of these ecosystems and the river water quality has become a high priority for federal and state governments and associated departments and agencies. Public concern is adding to the pressures on these departments and agencies to restore these ecosystems and to sustainably maintain the river water quality. The long term monitoring of floodplain wetlands has been limited, compounding the difficulties faced by managers and decision makers on assessing the potential outcome of restoration options. The role of this project in the broad scheme of restoration/rehabilitation is to contribute to the construction of a model capable of increasing managers and decision makers understanding, and build consensus of potential outcomes of management option. This model was to use available data. The developed model, based on WETMOD developed by Cetin (2001), simulates wetland internal nutrient processes, phytoplankton, zooplankton and macrophyte biomass as well as the interaction (nutrient and phytoplankton exchange) between wetlands and the river. The model further simulates the potential impact management options have on the wetlands, and their nutrient retention capacity, and therefore their impact on the river nutrient load. Due to the limitation of data, wetlands were considered in categories for which data was available. Of these two had sufficient data to develop, calibrate and validate the model. Management scenarios for these two wetlands were developed. These scenarios included, the impact of returning a degraded wetland in a turbid state to a rehabilitated clear state, and the impact the removal of nutrient from irrigation drainage inflows has on wetland nutrient retention, and consequent input to the river. Scenarios of the cumulative impact of the management of multiple wetlands were developed based on using these two wetlands, for which adequate data was available, as “exemplar” wetlands, i.e. data from these wetlands were substituted for other similar wetlands (those identified as belonging to the same category). The model scenarios of these multiple wetlands provide some insight into the potential response management may have on individual wetlands, the cumulative impact on river nutrient load and how wetland morphology may relate to management considerations. The model is restricted by data availability and consequently the outputs. Further, some limitations identified during the development of the model need to be addressed before it can be applied for management purposes. However, the model and methods provide a guide by which monitoring efforts can assist in developing future modelling assessments and gain a greater insight not only at the monitoring site but also on a landscape scale.
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

This study has several objectives. Firstly, to investigate the sexual reproductive ecology and germination requirements of Bolboschoenus caldwellii and Bolboschoenus medianus. Secondly, to examine the asexual growth mechanisms and responses of Bolboschoenus caldwellii and Bolboschoenus medianus to interesting salinity. Thirdly, to assess the genetic diversity of Bolboschoenus caldwellii and Bolboschoenus medianus stands from three wetlands with contrasting environmental conditions in the Gippsland Lakes region.

Research Doctorate - Doctor of Philosophy (PhD)
The Earth is experiencing a period of mass extinction due to human development and expansion (Wake & Vredenburg 2008). It has been estimated that 866 animal, plant, fungi and protist species have become extinct in recent history, and 25,821 species were declared either Critically Endangered, Endangered or Vulnerable in 2017 (IUCN 2017). Causal agents of population declines and biodiversity loss include climate change, land clearing, habitat modification and the introduction of exotic competitor or predator species (Vitousek et al. 1997) and disease (Skerratt et al. 2007) which affect species from global to local scales. The magnitude of species loss and threat of further extinctions has caused worldwide attention, instigating efforts to identify and conserve species at risk (Redford & Richter 1999). Species management programs typically aim to identify causal agents of decline, assess species requirements for survival and reproduction and understand population proce sses so that informed decisions can be made to reverse population declines. An important step in this process is gaining an understanding of the factors which affect species distribution (Guisan et al. 2013; Noss et al. 1997). Conservation programs often aim to understand an animal’s distribution by identifying what constitutes habitat. Factors commonly examined include abiotic and biotic attributes of the landscape including available shelter and food, as well as an animal’s interaction with heterospecifics (Campomizzi et al. 2008). In the instance that these factors or interactions correlate with species presence or abundance either positively or negatively, it is assumed that these factors are actively selected for or avoided (Batt 1992). However, additional behavioural factors can affect distribution, such as attraction to (Ahlering et al. 2010) or avoidance of conspecifics (same species) (Keren-Rotem et al. 2006; Stamps 1983), causing strong aggregations or segregation of animal distribution over a landscape, respectively. Despite the influence of these factors on distribution, conspecific attraction and avoidance are not commonly considered by conservation programs when attempting to understand, predict and alter species distributions (Campomizzi et al. 2008). As animals experiencing conspecific attraction or avoidance may deviate from the correlation model assumed by habitat selection, research programs aimed at assisting endangered species cannot afford to ignore conspecific interactions (Manly et al. 2009). A last resort for conservation initiatives is breeding animals in captivity, creating or restoring habitat and translocating animals back into populations that are experiencing population decline or have become locally extinct. Current research in conservation biology has focused on identifying and assessing animal behaviour which can limit the success of conservation initiatives such as; multi-spatial-level habitat selection (McGarigal et al. 2016), conspecific attraction (Campomizzi et al. 2008) and mate selection within captive breeding (Chargé et al. 2014a; Chargé et al. 2014b). As these factors influence species distribution and survival, they therefore affect the success of habitat construction programmes and the persistence of naturally occurring or translocated populations. Amphibians are a globally threatened taxon with 33 extinct species and 2,100 species declared either critically endangered, endangered or vulnerable (IUCN 2017). Factors causing amphibian decline include the human facilitated spread of chytrid fungus (Batrachochytrium dendrobatidis) (Skerratt et al. 2007), global climate change, introduced species as well as habitat loss and modification (Brown et al. 2012; Stuart et al. 2004). Considerable research has been undertaken on causal agents of decline, along with understanding population processes and habitat requirements that affect the persistence of populations (Wake & Vredenburg 2008). Despite the fact that many amphibian species show signs of conspecific attraction and/or avoidance, the influence of conspecific interactions on spatial distribution and subsequent declines of amphibians is under-investigated. This current research project explores the potential for particular behaviours which may influence species distribution and the success of habitat creation and translocation programmes for the green and golden bell frog (Litoria aurea). For the first research paper, I assessed conspecific call attraction in L. aurea. Over a landscape, animal distributions can be skewed as a result of conspecific attraction and aggregation. This can hinder habitat restoration and creation programmes as species may fail to colonise available habitat, despite its suitability. It has been noted from past research that L. aurea uses particular habitat and has distributional traits which suggest the presence of conspecific attraction, and using speakers playing calls can successfully attracted L. aurea at short distances, forming new aggregations (James et al. 2015: Attachment 1). In the first research chapter, I aimed to use speaker systems playing calls to manipulate the landscape distribution of L. aurea. I placed a stand with a speaker playing call broadcast in a treatment waterbody (T), a stand with no calls broadcasted as a manipulative control (MC) and no stand or speakers as a control (C). This design was replicated in five areas on Kooragang Island, Australia, and waterbodies were surveyed to measure changes in abundance and calling over two and a half breeding seasons. We found that speaker introduction did not increase abundance or calling at T relative to MC and C. We did, however, find that the length of time males called was longer at T, compared to MC and C. As the length of calling time may be extended using conspecific call broadcast , provision of conspecific stimulation at translocation sites may improve breeding activity and retention of the population post-release by reducing dispersal. For the second research chapter, I assessed habitat selection of L. aurea. The site selection of breeding individuals is a crucial component of a species habitat selection and can help to direct conservation programmes. However, very little is known about the microhabitat selection of calling male L. aurea. This study aimed to distinguish if male aggregations are associated with specific habitat features within a waterbody and describe their use of available habitat structures. Within waterbodies we compared calling locations relative to non-calling locations for water variables (temperature, salinity, dissolved oxygen), microclimate (temperature, humidity, average and maximum wind speed) and habitat (percentage coverage of water, ground, emergent vegetation and floating vegetation). Overall, males were associated with lower salinity and higher dissolved oxygen, higher percentage coverage of emergent vegetation and bare ground, and low percentage coverage of open water. Males were most commonly found in the water floating between or beside emergent vegetation or perched on emergent vegetation above water level. This suggests that males may select habitat to protect themselves from predators, or for breeding; providing appropriate vegetation, dissolved oxygen and salinity for embryo and tadpole development. This provides supportive information for previous studies on habitat selection, indicating what habitat is preferred by breeding males to improve monitoring, habitat creation and rehabilitation. For the third research chapter, I assess a habitat construction programme. Habitat creation programmes are often used to compensate for the loss of habitat for endangered species, with varying results. I describe an early stage wetland construction programme implemented for L. aurea on Ash Island, NSW Australia. Seven ephemeral (flooding) and two permanent waterbodies were constructed near an existing population. The wetland was designed to increase landscape aquatic habitat, based on adaptive management learnings from past research. In this study, I assess the initial use of this habitat by L. aurea, and initial findings on the design suitability. Surveys in constructed wetlands and in the broader Kooragang area showed that L. aurea rapidly colonised and called at constructed ephemeral wetlands but not permanent wetlands. The chorus size in constructed wetlands was large in comparison to other populations in coastal NSW, and a range of other frog species also bred onsite. Female L. aurea used a nearby remnant wetland (adjacent to the constructed wetlands), and used different habitat to males. Similar habitat use variation between sexes was reflected in the broader population. Most male and female L. aurea captured on Ash Island were under 12 months of age, and body condition in the constructed wetlands was higher than in the broader population. Waterbody design successfully protected waterbodies from overland flooding, and ephemeral waterbodies dried, which suggests the drying regime may protect the constructed habitat long-term from infestation of predatory fish. Elevated salinity from ground water in permanent waterbodies (intended to ameliorate chytrid disease in the landscape) was higher than anticipated and requires further monitoring. It is hoped that this programme may help guide other conservation projects creating habitat for amphibians under threat. For the fourth research paper, I assess sexual selection in L. aurea. As a conservation strategy for L. aurea, captive breeding programmes supplement at-risk populations and translocate individuals to their former ranges. However, breeding programmes are undertaken with very little information on sexual selection and its exclusion can reduce the fitness of released animals. The aim of the fourth study was to assess whether forms of sexual selection occur for L. aurea to inform captive breeding programmes. In the wild I studied mate selection. Firstly, we aimed to assess if the size and body condition of amplexing individuals (grasping to breed), differed from other individuals in the population as an indication of female sexual selection or male-male competition. Secondly, we investigated if male and female amplexing pairs were size correlated as an indicator of size assortative mating, and thirdly we made observations on behavioural interactions in the breeding waterbody to complement the analysis. In Whangarei, New Zealand, we captured L. aurea over 4 survey nights, undertaking capture-mark-recapture and measuring morphometrics of snout vent length (SVL), right tibia length (RTL) and weight, calculated body condition. We compared the SVL, RTL and weight of breeding individuals to non-breeding individuals and found that amplexing males were larger with better body condition, however, female size did not differ. Male-female pairs were not size assortative and aggressive interactions were recorded between males. Larger male size may be an indicator of either female selectivity or larger-male mating advantage through aggressive interactions. As removal of sexual selection in captive breeding programmes can reduce fitness and place conservation initiatives at risk, I recommend incorporating sexual selection by placing multiple males of varying sizes in breeding tanks with females to facilitate female selectivity or larger-male mating advantage. Based on the results of the current studies, I have identified possible constraints on the use of conspecific attraction for this species, and also recognised its potential use in translocations programmes to improve project outcomes. As a result of microhabitat assessment, habitat creation and management programmes can use specific parameters to design, maintain and monitor habitat for calling males. Assessment of a habitat construction project designed from previous research recommendations shows initial project success and provides information to refine future habitat construction programmes. Finally, assessment of sexual selection in L. aurea provides vital information to conservation programmes breeding animals for translocation to work toward improving the fitness of released individuals. Overall, the current study provides key aspects of L. aurea’s biology and ecology that have not been clearly addressed in the literature and aims to improve conservation efforts. In light of recent extinctions and increasing pressures on wildlife, continued research on key threatening processes and behavioural ecology is crucial to help guide conservation.