ORCID Profile
0000-0001-8408-9142
Current Organisation
University of Adelaide
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Ecosystem Function | Surfacewater Hydrology | Environmental Science and Management | Ecological Applications | Macromolecular and Materials Chemistry | Environmental Engineering Modelling | Chemical Characterisation of Materials | Natural Resource Management | Environmental Monitoring | Environmental Nanotechnology | Freshwater Ecology
ANZSRC Socio-Economic Objective (SEO)
Ecosystem Adaptation to Climate Change | Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments | Urban Water Evaluation (incl. Water Quality) | Physical and Chemical Conditions of Water in Fresh, Ground and Surface Water Environments (excl. Urban and Industrial Use) | Physical and Chemical Conditions of Water in Coastal and Estuarine Environments | Expanding Knowledge in the Environmental Sciences | Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Physical Sciences | Rural Water Evaluation (incl. Water Quality) |
Related Links
Publications
Water quality trends in the Three Gorges Reservoir region before and after impoundment (1992–2016)
Publisher: Elsevier BV
Date: 07-2019
Extreme water level decline effects sediment distribution and composition in Lake Alexandrina, South Australia
Publisher: Springer Science and Business Media LLC
Date: 14-01-2014
Advection, growth and nutrient status of phytoplankton populations in the lower River Murray, South Australia
Publisher: Wiley
Date: 2000
DOI: 10.1002/1099-1646(200007/08)16:4<327::AID-RRR576>3.0.CO;2-Q
Bacterial degradation of microcystin toxins within a biologically active sand filter
Publisher: Elsevier BV
Date: 02-2006
DOI: 10.1016/J.WATRES.2005.12.009
Abstract: Microcystin toxins are a problem for water authorities as they are recalcitrant to conventional water treatment. In this study, biological sand filtration was assessed in laboratory column experiments for its ability to remove two microcystin analogues, microcystin-LR and microcystin-LA. A lag period of 3 days was evident prior to the commencement of degradation. Contact times were varied during the experiment however, no microcystin was detected in the effluent after 4 days, even under conditions similar to those of a rapid sand filter. Removals of microcystin through the sand filters were shown to be primarily through biological degradation processes. Using polymerase chain reaction (PCR), biofilm, extracted from one of the sand filters that had effectively removed the microcystins, was shown to contain bacteria with the mlrA gene. Detection of this gene provided additional evidence that biological degradation of microcystin was the primary removal mechanism.
Socio-Cultural Values of Ecosystem Services from Oak Forests in the Eastern Himalaya
Publisher: MDPI AG
Date: 15-04-2019
DOI: 10.3390/SU11082250
Abstract: Identification and assessment of socio-cultural values of ecosystem services are increasingly important for the planning and management of forest resources. Key information necessary is how different forest user groups perceive and prioritize different ecosystem services based on their local setting. We assessed the socio-cultural values of ecosystem services of high-altitude oak forests in Western Bhutan using participatory approaches with two important forest users: local communities and forest experts. We found that these forests serve as a pool of 22 ecosystem services under four MEA categories of provisioning (9), regulating (8), supporting (2), and cultural (3) services. Fresh water was unanimously identified as the most valuable service, as well as the most vulnerable, by both the groups. The priorities of local communities inclined towards provisioning and cultural services due to their dependence on these services for their livelihood and wellbeing. Forest experts’ priorities were more evenly spread over three categories of services: provisioning, regulating, and supporting services, reflecting their broader interest in resource management, bio ersity conservation, and climate change mitigation. Several regulating and supporting services were not easily identified by many villagers, suggesting that bridging the priorities of local interests with broader national forestry goals may require public partnerships and integrated decision-making about the entire suite of ecosystem services. Several management interventions proposed by the groups were presented for consideration by local users, scientists, and policy makers. For all ongoing and future ecosystem service assessments, we recommend the integration of socio-cultural values with biophysical and monetary assessments to fully value the benefits from the high-altitude oak forests.
The persistence of cyanobacterial (M icrocystis spp.) blooms throughout winter in Lake Taihu, China
Publisher: Wiley
Date: 17-12-2015
DOI: 10.1002/LNO.10246
Sediment oxygen demand in a constructed lake in south-eastern Australia
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.JENVMAN.2016.07.008
Abstract: The occurrence of hypoxia and anoxia in aquatic environments is increasing, driven by changes in land use and alteration of flow regimes. Periods of low oxygen impact bio ersity and water quality for both recreational and consumptive users. We use the Torrens Lake as a case study to assess pelagic, benthic and resuspended sediment oxygen demand, and the release of sediment bound phosphorus to determine the relative role of internal and external loading on water quality in a lake within a heavily urbanised landscape. Our results indicate temporal shifts in the dominant oxygen demanding process in the lake. During periods of no-inflow, sediment oxygen demand is the dominant process during periods of inflow resulting from wet weather conditions, pelagic rather than sediment derived oxygen demand becomes the governing process. The inlet end of the lake is a depositional zone for stormwater borne sediments. Resuspended sediments at the inlet end of the lake exert a higher oxygen demand than those from the outlet, and represent a larger pool of potentially mobile phosphorus compared to sediments at the outlet end of the lake. However, external rather than internal loading appears to be the dominant driver of water quality in this lake.
Rapid and highly variable warming of lake surface waters around the globe
Publisher: American Geophysical Union (AGU)
Date: 16-12-2015
DOI: 10.1002/2015GL066235
Discriminating and assessing adsorption and biodegradation removal mechanisms during granular activated carbon filtration of microcystin toxins
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.WATRES.2007.05.057
Abstract: Microcystins are cyanobacterial toxins that are problematic for water authorities due to their resistance to conventional water treatment. Granular activated carbon (GAC) filtration has been shown to be effective in removing microcystin from water using both adsorption and biodegradation removal mechanisms however, little is known regarding which removal mechanism predominates and to what extent. In this study, microcystin removal due to adsorption and biodegradation in GAC filtration were discriminated and assessed by commissioning three parallel laboratory columns, including a sterile GAC column, a conventional GAC column and a sand column. The results demonstrate that biodegradation is an efficient removal mechanism once it commences and that the rate of biodegradation was dependent upon temperature and initial bacterial concentration. Adsorption of microcystins was prevalent during the initial stages of the GAC columns and was modelled using the homogeneous surface diffusion model (HSDM). The HSDM provided evidence that an active biofilm present on the surface of the conventional GAC hindered adsorption of microcystin compared with the sterile GAC with no active biofilm. Up to 70% removal of microcystin-LR was still observed after 6 months of operation of the sterile GAC column, indicating that adsorption still played a vital role in the removal of this toxin.
Eco-physiological adaptations that favour freshwater cyanobacteria in a changing climate
Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.WATRES.2011.12.016
Abstract: Climate change scenarios predict that rivers, lakes, and reservoirs will experience increased temperatures, more intense and longer periods of thermal stratification, modified hydrology, and altered nutrient loading. These environmental drivers will have substantial effects on freshwater phytoplankton species composition and biomass, potentially favouring cyanobacteria over other phytoplankton. In this Review, we examine how several cyanobacterial eco-physiological traits, specifically, the ability to grow in warmer temperatures buoyancy high affinity for, and ability to store, phosphorus nitrogen-fixation akinete production and efficient light harvesting, vary amongst cyanobacteria genera and may enable them to dominate in future climate scenarios. We predict that spatial variation in climate change will interact with physiological variation in cyanobacteria to create differences in the dominant cyanobacterial taxa among regions. Finally, we suggest that physiological traits specific to different cyanobacterial taxa may favour certain taxa over others in different regions, but overall, cyanobacteria as a group are likely to increase in most regions in the future.
Flow variability and longitudinal characteristics of organic carbon in the Lachlan River, Australia
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/MF12297
Abstract: Heterotrophic organic-carbon cycling is a major source of energy to aquatic food webs, yet there are few studies into patterns of heterotrophic productivity in large lowland rivers. The Lachlan River experienced a period of extreme flow variability from September 2010 to February 2011 for ex le, daily discharge (ML day–1) at one site reached times its 10-year average. Heterotrophic cycling of dissolved organic carbon (DOC) and particulate organic carbon (POC) were assessed over this period at six sites on the Lachlan River. Concentrations of total organic carbon (TOC) ranged from 7 to 30 mg L–1, of which the majority was in dissolved form. Concentration of DOC was positively correlated with daily discharge. Biochemical oxygen demand of TOC over 5 days (BOD5) showed significant variability, ranging from 0.6 to 6.6 mg O2 L–1. BOD5 did not appear related to discharge, but instead to a range of other factors, including regulation via weirs, lateral and longitudinal factors. Partitioning of DOC and POC showed that POC had an influence on BOD5 comparable to DOC. This is relevant to environmental-flow management in the Lachlan River, the Murray–Darling Basin and rivers generally, by showing that flow variability influences a fundamental ecosystem characteristic, namely organic carbon.
Assessing, quantifying and valuing the ecosystem services of coastal lagoons
Publisher: Elsevier BV
Date: 07-2018
Hydrological-niche models predict water plant functional group distributions in diverse wetland types
Publisher: Wiley
Date: 21-04-2017
DOI: 10.1002/EAP.1529
Abstract: Human use of water resources threatens environmental water supplies. If resource managers are to develop policies that avoid unacceptable ecological impacts, some means to predict ecosystem response to changes in water availability is necessary. This is difficult to achieve at spatial scales relevant for water resource management because of the high natural variability in ecosystem hydrology and ecology. Water plant functional groups classify species with similar hydrological niche preferences together, allowing a qualitative means to generalize community responses to changes in hydrology. We tested the potential for functional groups in making quantitative prediction of water plant functional group distributions across erse wetland types over a large geographical extent. We s led wetlands covering a broad range of hydrogeomorphic and salinity conditions in South Australia, collecting both hydrological and floristic data from 687 quadrats across 28 wetland hydrological gradients. We built hydrological-niche models for eight water plant functional groups using a range of candidate models combining different surface inundation metrics. We then tested the predictive performance of top-ranked in idual and averaged models for each functional group. Cross validation showed that models achieved acceptable predictive performance, with correct classification rates in the range 0.68-0.95. Model predictions can be made at any spatial scale that hydrological data are available and could be implemented in a geographical information system. We show the response of water plant functional groups to inundation is consistent enough across erse wetland types to quantify the probability of hydrological impacts over regional spatial scales.
Improving water quality in China: Environmental investment pays dividends
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.WATRES.2017.04.035
Abstract: This study highlights how Chinese economic development detrimentally impacted water quality in recent decades and how this has been improved by enormous investment in environmental remediation funded by the Chinese government. To our knowledge, this study is the first to describe the variability of surface water quality in inland waters in China, the affecting drivers behind the changes, and how the government-financed conservation actions have impacted water quality. Water quality was found to be poorest in the North and the Northeast China Plain where there is greater coverage of developed land (cities + cropland), a higher gross domestic product (GDP), and higher population density. There are significant positive relationships between the concentration of the annual mean chemical oxygen demand (COD) and the percentage of developed land use (cities + cropland), GDP, and population density in the in idual watersheds (p < 0.001). During the past decade, following Chinese government-financed investments in environmental restoration and reforestation, the water quality of Chinese inland waters has improved markedly, which is particularly evident from the significant and exponentially decreasing GDP-normalized COD and ammonium (NH
Investigations into the biodegradation of microcystin-LR in wastewaters
Publisher: Elsevier BV
Date: 15-08-2010
DOI: 10.1016/J.JHAZMAT.2010.04.081
Abstract: Microcystins are potent hepatotoxins that can be produced by cyanobacteria. These organisms can proliferate in wastewaters due to a number of factors including high concentrations of nutrients for growth. As treated wastewaters are now being considered as supplementary drinking water sources, in addition to their frequent use for irrigated agriculture, it is imperative that these wastewaters are free of toxins such as microcystins. This study investigated the potential for biodegradation of microcystin-LR (MCLR) in wastewaters through a biological sand filtration experiment and in static batch reactor experiments. MCLR was effectively removed at a range of concentrations and at various temperatures, with degradation attributed to the action of microorganisms indigenous to the wastewaters. No hepatotoxic by-products were detected following the degradation of MCLR as determined by a protein phosphatase inhibition assay. Using TaqMan polymerase chain reaction, the first gene involved in bacterial degradation of MCLR (mlrA) was detected and the responsible bacteria shown to increase with the amount of MCLR being degraded. This finding suggested that the degradation of MCLR was dependent upon the abundance of MCLR-degrading organisms present within the wastewater, and that MCLR may provide bacteria with a significant carbon source for proliferation in turn increasing MCLR removal.
Retention of nitrogen, phosphorus and silicon in a large semi-arid riverine lake system
Publisher: Springer Science and Business Media LLC
Date: 08-11-2010
Numerical models for management of Anabaena circinalis
Publisher: Springer Science and Business Media LLC
Date: 12-2004
Ecosystem science: Toward a new paradigm for managing Australia's inland aquatic ecosystems
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/MF08188
Abstract: Freshwater ecosystems are a foundation of our social, cultural, spiritual and economic well being. The degraded condition of many of Australia’s river ecosystems is testament to our failure to manage these resources wisely. Ecosystem science involves the holistic study of complex biophysical systems to understand the drivers that influence ecological pattern and process. Ecosystem science should underpin both water management and policy. Our understanding of aquatic ecosystems lags behind the increasing problems caused by past land and water management. Current post-graduate training programmes will not provide the aquatic ecosystem scientists needed by government and management agencies to prevent further degradation. We advocate new initiatives to capture the skills, knowledge and innovation of our research community by engaging scientists and managers in large-scale, long-term ecosystem science programmes across Australia and to integrate these programmes with community aspirations, policy, planning and management. We call on management agencies to increase their support for and uptake and use of ecosystem science. We also advocate establishment of national archives for long-term ecologically-relevant data and s les, and clear custodial arrangements to protect, update and facilitate knowledge-transfer. These initiatives need to be supported by more extensive, better-funded post-graduate and post-doctoral programmes in ecosystem science and management.
Rapid utilisation of storm water-derived dissolved organic carbon and its fractions in an urban lake
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/MF12287
Abstract: Hypoxia occurred in the Torrens Lake, South Australia, after a 16-mm rainfall which discharged high concentrations of dissolved organic carbon (DOC) into the Lake. This work explores the hypothesis that hypoxia was correlated with the bioavailability of DOC. Carbonaceous biological oxygen demand and a decrease in DOC from s les collected immediately after stormwater was discharged into the Lake confirmed the presence of an active aerobic microbial community. In addition, the inlet and outlet of the Lake were monitored over a 10-day period. Dissolved oxygen fell from 10 to mg L–1 within 44 h as the DOC increased and then decreased. A similar pattern occurred at the outlet after a lag of 20 h. At the inlet, because minimal mixing with the Lake water occurred, the rapid decrease of DOC and its fractions was interpreted as a function of aerobic microbial activity. Aquatic humic substances (AHS) were metabolised fastest, followed by hydrophilic acids (HiA) and hydrophilic neutrals (HiN). The warm nature of Mediterranean water bodies during summer may make them more susceptible to hypoxia as the frequency of extreme droughts allow accumulation of leaf litter and other debris that is subsequently mobilised by episodic floods.
Separation of forms of microcystis from anabaena in mixed populations by the application of pressure
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/MF9940863
Abstract: Critical-pressure distributions of gas vesicles in Anabaena circinalis, Microcystis aeruginosa f. aeruginosa and M. a. f. flos-aquae were determined for suspensions both in hypertonic sucrose solutions and in reservoir water. The differences between the critical and apparent critical pressures of gas vesicles suggested that differential pressurization could be used to separate these taxa. Subsequent experiments successfully separated ( %) the two formae of Microcystis by the application of 500 kPa and M. a. f. aeruginosa from A. circinalis by the application of 300 kPa. This technique has the potential to provide sufficiently pure material to distinguish the relative toxicity of the two formae of Microcystis in the presence of a neurotoxic A. circinalis.
Green algal over cyanobacterial dominance promoted with nitrogen and phosphorus additions in a mesocosm study at Lake Taihu, China
Publisher: No publisher found
Date: 2015
DOI: 10.1007/S11356-014-3930-4
Abstract: Enrichment of waterways with nitrogen (N) and phosphorus (P) has accelerated eutrophication and promoted cyanobacterial blooms worldwide. An understanding of whether cyanobacteria maintain their dominance under accelerated eutrophication will help predict trends and provide rational control measures. A mesocosm experiment was conducted under natural light and temperature conditions in Lake Taihu, China. It revealed that only N added to lake water promoted growth of colonial and filamentous cyanobacteria (Microcystis, Pseudoanabaena and Planktothrix) and single-cell green algae (Cosmarium, Chlorella, and Scenedesmus). Adding P alone promoted neither cyanobacteria nor green algae significantly. N plus P additions promoted cyanobacteria and green algae growth greatly. The higher growth rates of green algae vs. cyanobacteria in N plus P additions resulted in the biomass of green algae exceeding that of cyanobacteria. This indicates that further enrichment with N plus P in eutrophic water will enhance green algae over cyanobacterial dominance. However, it does not mean that eutrophication problems will cease. On the contrary, the risk will increase due to increasing total phytoplankton biomass.
Comparison of efficacy of two p-inactivation agents on sediments from different regions of lake taihu: Sediment core incubations
Publisher: Schweizerbart
Date: 12-2012
Ecology: Resilience to blooms
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-10-2011
Abstract: Managing nitrogen and phosphorus pollution of fresh water may decrease the risk of cyanobacterial blooms, even in the face of warming temperatures.
Reservoir Inflow Monitoring for Improved Management of Treated Water Quality-A South Australian Experience
Publisher: Springer Science and Business Media LLC
Date: 18-05-2010
Effect of discharges on the effectiveness of the Cox Creek wetland system, South Australia
Publisher: Science Alert
Date: 15-08-2014
Influence of the three Gorges Reservoir on the shrinkage of China's two largest freshwater lakes
Publisher: Elsevier BV
Date: 06-2019
Effects of light history on primary productivity in a phytoplankton community dominated by the toxic cyanobacterium Cylindrospermopsis raciborskii
Publisher: Wiley
Date: 12-01-2009
Biological filtration for the removal of algal metabolites from drinking water
Publisher: IWA Publishing
Date: 03-2006
DOI: 10.2166/WS.2006.064
Abstract: Biological sand filters were assessed for their ability to remove geosmin, 2-methylisoborneol (MIB) and microcystin-LR. Microcystin-LR was the most readily degradable metabolite with a maximum lag period of only 5 days before it was undetected in the filter effluent. Geosmin and MIB were difficult to degrade, with a period in excess of 75 days before greater than 95% removal was achieved. A microcystin-degrading gene was detected in the biofilm from one of the filters, confirming that the biofilm possessed the ability to degrade microcystin. A Sphingomonas sp. was identified as a potential geosmin degrader based on denaturing gradient gel electrophoresis (DGGE) analysis. DGGE analysis revealed a more complex bacterial community during the degradation of MIB, suggesting that more than one bacterium may be responsible for its degradation.
A ‘lost life’: coming to terms with haemodialysis
Publisher: Wiley
Date: 09-05-2014
DOI: 10.1111/JOCN.12577
Abstract: To describe the essence of the lived experience of patients and families in the early phase of long-term haemodialysis therapy. Past qualitative research has taken a long-term view describing established haemodialysis therapy as it impacts on physical limitations and changes in self-concept, psychosocial well-being and sense of dignity with subsequent consequences for family roles and financial status. This study used the qualitative approach of Heideggerian phenomenology. Eleven patients with end-stage kidney disease who had recently initiated haemodialysis and five family carers engaged in semi-structured interviews. These were recorded and transcribed verbatim and analysed using an hermeneutic framework. The essence of the early dialysis experience was a 'lost life', and participants were overwhelmed by shock and grief. This appeared to result from a lack of mental and physical preparation for dialysis as a long-term management strategy. A loss of sense of self, loss of spontaneity and personal freedom and loss of social connectedness challenged the participants' ability to contribute to family and community. Changed body sensations ranged from improved wellness to a sense of depletion and fatigue. Family caregivers found the caring role was unremitting and required intense vigilance. Patients and family members in the early phase of dialysis may have difficulty perceiving a positive future. A greater focus on preparation for the possibility of dialysis and frameworks of care that support adjustment to this new way of life are of vital importance. Family presence during haemodialysis and support groups for patients and family should be actively facilitated.
Removal of cyanobacterial metabolites through wastewater treatment plant filters
Publisher: IWA Publishing
Date: 04-2012
DOI: 10.2166/WST.2012.002
Abstract: Wastewaters have the potential to proliferate excessive numbers of cyanobacteria due to high nutrient levels. This could translate to the production of metabolites, such as the saxitoxins, geosmin and 2-methylisoborneol (MIB), which can impair the quality of wastewater destined for re-use. Biological sand filtration was assessed for its ability to remove these metabolites from a wastewater. Results indicated that the sand filter was incapable of effectively removing the saxitoxins and in some instances, the effluent of the sand filter displayed greater toxicity than the influent. Conversely, the sand filter was able to effectively remove geosmin and MIB, with removal attributed to biodegradation. Granular activated carbon was employed as an alternative filter medium to remove the saxitoxins. Results showed similar removals to previous drinking water studies, where efficient removals were initially observed, followed by a decrease in the removal a consequence of the presence of competing organics which reduced adsorption of the saxitoxins.
Interannual variability in rainfall and its impact on nutrient load and phytoplankton in Myponga Reservoir, South Australia
Publisher: Informa UK Limited
Date: 09-2004
A three dimensional model ofCryptosporidiumdynamics in lakes and reservoirs: A new tool for risk management
Publisher: Informa UK Limited
Date: 09-2004
Water Depth Underpins the Relative Roles and Fates of Nitrogen and Phosphorus in Lakes
Publisher: American Chemical Society (ACS)
Date: 19-02-2020
Floodplain connectivity facilitates significant export of zooplankton to the main River Murray channel during a flood event
Publisher: Freshwater Biological Association
Date: 10-2014
DOI: 10.5268/IW-4.4.696
The influence of experimentally generated turbulence on the Mash01 unicellular Microcystis aeruginosa strain
Publisher: Springer Science and Business Media LLC
Date: 04-2004
Vertical migration, entrainment and photosynthesis of the freshwater dinoflagellate Peridinium cinctum in a shallow urban lake
Publisher: Oxford University Press (OUP)
Date: 02-2004
In situ evidence for the association of total coliforms and Escherichia coli with suspended inorganic particles in an Australian reservoir
Publisher: Springer Science and Business Media LLC
Date: 02-2006
Why Lake Taihu continues to be plagued with cyanobacterial blooms through 10 years (2007–2017) efforts
Publisher: Elsevier BV
Date: 03-2019
Applications of ecological stoichiometry for sustainable acquisition of ecosystem services
Publisher: Wiley
Date: 22-02-2025
DOI: 10.1111/J.0030-1299.2005.14051.X
Abstract: Human activities have differentially altered biogeochemical cycling at local, regional and global scales. We propose that a stoichiometric approach, examining the fluxes of multiple elements and the ratio between them, may be a useful tool for better understanding human effects on ecosystem processes and services. The different scale of impacts of the elements carbon, nitrogen and phosphorus and the different nature of their biogeochemical cycles, imply a large variation of their stoichiometric ratios in space and time and thus ergent impacts on biota. In this paper, we examine the effects of anthropogenic perturbations on nutrient ratios in ecosystems in two ex les and one case study. Altered stoichiometry in agricultural systems (ex le 1) can affect not only crop yield and quality but also the interactions between plants and their pollinators, pests and pathogens. Human activities have also altered stoichiometry in coastal ecosystems (ex le 2). Increased N loading has especially lead to increased N:P and reduced Si:N ratios, with detrimental effects on ecosystem services derived from coastal pelagic food webs, such as fish yield and water quality. The terrestrial–aquatic linkage in stoichiometric alterations is illustrated with a case study, the Mississippi River watershed, where anthropogenic activities have caused stoichiometric changes that have propagated through the watershed into the northern Gulf of Mexico. Coupled with altered stoichiometric nutrient inputs are the inherent differences in variation and sensitivity of different ecosystems to anthropogenic disturbance. Furthermore, the connections among the components of a watershed may result in downstream cascades of disrupted functioning. Applying a multiple element perspective to understanding and addressing societal needs is a new direction for both ecological stoichiometry and sustainability.
The effects of various control and water treatment processes on the membrane integrity and toxin fate of cyanobacteria
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.JHAZMAT.2013.10.059
Abstract: Cyanobacterial blooms are one of the main contaminants that can degrade drinking water quality with the associated taste, odour and toxic compounds. Although a wide range of techniques have shown promise for cyanobacterial bloom control and cyanobacterial cell/metabolite removal in reservoirs and water treatment plants (WTPs), these treatments may have negative consequences through release of intracellular metabolites into the surrounding water. This study assessed the impact of copper sulphate (CuSO4), chlorine, potassium permanganate (KMnO4), hydrogen peroxide (H2O2) and ozone on Microcystis aeruginosa culture and the toxins it produced. All of these agents induced the loss of cyanobacterial membrane integrity. However, no associated increase in dissolved toxins was detected during chlorine and H2O2 treatments which may be due to faster toxin oxidation rates than release rates. KMnO4 doses of 1 and 3mgL(-1) degraded dissolved toxins while having no impact on cyanobacterial membrane integrity. In contrast, ozone induced a significant increase in extracellular toxins but it was unable to degrade these toxins to the same degree as the other oxidants which may due to the lack of residual. All chemicals, except CuSO4, were able to reduce cyanotoxins and chlorine was the most effective with a rate up to 2161M(-1)s(-1).
The role of phytoplankton as pre-cursors for disinfection by-product formation upon chlorination
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.WATRES.2016.06.024
Abstract: Water quality remains one of the greatest concerns with regards to human health. Advances in science and technology have resulted in highly efficient water treatment plants, significantly reducing diseases related to waterborne pathogenic microorganisms. While disinfection is critical to mitigate pathogen risk to humans, the reactions between the disinfectant and dissolved organic compounds can lead to the formation of chemical contaminants called disinfection by-products (DBPs). DBPs have been related to numerous health issues including birth defects and cancer. The formation of disinfection by-products occurs due to the reaction of oxidants and natural organic matter. DBP precursors are derived from anthropogenic sources including pharmaceuticals and chemical waste, the breakdown of vegetation from external catchment sources (allochthonous) and internally derived sources including phytoplankton (autochthonous). Current literature focuses on the contribution of allochthonous sources towards the formation of DBPs, however, the recalcitrant nature of hydrophilic phytoplankton derived organic matter indicates that autochthonous derived organic carbon can significantly contribute to total DBP concentrations. The contribution of phytoplankton to the formation of DBPs is also influenced by cellular exudation rates, chemical composition, environmental conditions and the physical and chemical conditions of the solution upon disinfection. Formation of DBPs is further influenced by the presence of cyanobacteria phyla due to their notoriety for forming dense blooms. Management of DBP formation can potentially be improved by reducing cyanobacteria as well as DBP precursors derived from other phytoplankton.
Predicting the resilience and recovery of aquatic systems: A framework for model evolution within environmental observatories
Publisher: American Geophysical Union (AGU)
Date: 09-2015
DOI: 10.1002/2015WR017175
Are nitrous oxide emissions indirectly fueled by input of terrestrial dissolved organic nitrogen in a large eutrophic Lake Taihu, China?
Publisher: Elsevier BV
Date: 06-2020
Benthic cyanobacteria: A source of cylindrospermopsin and microcystin in Australian drinking water reservoirs
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.WATRES.2017.07.073
Abstract: Cyanobacteria represent a health hazard worldwide due to their production of a range of highly potent toxins in erse aquatic environments. While planktonic species have been the subject of many investigations in terms of risk assessment, little is known about benthic forms and their impact on water quality or human and animal health. This study aimed to purify isolates from environmental benthic biofilms s led from three different drinking water reservoirs and to assess their toxin production by using the following methods: Enzyme-Linked Immunosorbent Assay (ELISA), High-Performance Liquid Chromatography (HPLC), Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and quantitative PCR (qPCR). Microscopic observation of the isolates allowed the identification of various filamentous cyanobacterial genera: Anabaena (benthic form), Calothrix and Nostoc from the Nostocales and Geitlerinema, Leptolyngbya, Limnothrix, Lyngbya, Oxynema, Phormidium and Pseudanabaena representing non-heterocystous filamentous cyanobacteria. The Phormidium ambiguum strain AWQC-PHO021 was found to produce 739 ng/mg of dry weight (d/w) of cylindrospermopsin and 107 ng/mg (d/w) of deoxy-cylindrospermopsin. The Nostoc linckia strain AWQC-NOS001 produced 400 ng/mg (d/w) of a microcystin analogue. This is the first report of hepatotoxin production by benthic cyanobacteria in temperate Australian drinking water reservoirs. These findings indicate that water quality monitoring programs need to consider benthic cyanobacteria as a potential source of toxins.
The influence of changes in wind patterns on the areal extension of surface cyanobacterial blooms in a large shallow lake in China
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.SCITOTENV.2015.02.090
Abstract: It has been hypothesized that climate change will induce the areal extension of cyanobacterial blooms. However, this hypothesis lacks field-based observation. In the present study both long-term historical data and short-term field measurement were used to identify the importance of changes in wind patterns on the cyanobacterial bloom in Lake Taihu (China), a large, shallow, eutrophic lake located in a subtropical zone. The cyanobacterial bloom mainly composed of Microcystis spp. recurred frequently throughout the year. The regression analysis of multi-year satellite image data extracted by the Floating Algae Index revealed that both the annual mean monthly maximum cyanobacterial bloom area (MMCBA) increased year by year from 2000 to 2011, while the contemporaneous cyanobacterial biomass showed no significant change. However, the correlation analysis shows that MMCBA was negatively correlated with wind speed. Our short-term field measurements indicated that the influence of wind on surface cyanobacterial blooms is that the Chlorophyll-a (Chla) concentration is fully mixing throughout the water column when the wind speed exceed 7 m s(-1). At lower wind speeds, there was vertical stratification of Chla with high surface concentrations and an increase in bloom area. The regression analysis of wind speed indicates that the climate has changed over the last decade. Lake Taihu has become increasingly calm, with the decrease of strong wind frequency between 2000 and 2011, corresponding to the increase in the MMCBA over time. Therefore, we conclude that changes in wind patterns related to climate change have favored the increase of cyanobacterial blooms in Lake Taihu.
Geographic and temporal variations in turbulent heat loss from lakes: A global analysis across 45 lakes
Publisher: Wiley
Date: 07-08-2018
DOI: 10.1002/LNO.10950
Snapshot Surveys for Lake Monitoring, More Than a Shot in the Dark
Publisher: Frontiers Media SA
Date: 28-11-2018
Lakes and Reservoirs of Australia and New Zealand
Publisher: Elsevier
Date: 2009
Toolbox for the sampling and monitoring of benthic cyanobacteria
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.WATRES.2019.115222
Abstract: Benthic cyanobacteria are a nuisance because they produce highly potent toxins and taste and odour compounds. Despite this, benthic cyanobacteria remain far less studied than their planktonic counterparts. For ex le, little is known about their growth or the seasonality of their secondary metabolite production. Moreover, s ling and monitoring techniques commonly used for the survey of planktonic species are not necessarily applicable to benthic forms. This study aimed to develop and validate a new s ling device for the routine monitoring of benthic mats. Molecular monitoring techniques were established and validated on environmental s les collected in a South Australian reservoir (SA-L2). A total of eight qPCR assays were applied to s les in order to track seasonal variations in cyanobacteria concentrations and associated secondary metabolite production. Next Generation Sequencing was utilised to conduct a microbial community composition analysis and to select the most appropriate substrate material for the s ling of benthic cyanobacteria. The concentration of the secondary metabolites geosmin and 2-methyl-isoborneol were quantified using High-Performance Liquid Chromatography, and concentrations of key nutrients (N, P) were quantified in water s les. The s ling device designed proved efficient and easy to use in the field. The qPCR assay designed for the lification of the cyanobacterial MIB synthase had a high efficiency with a minimum limit of quantification of 4 cell-equivalents per reaction and identified a potential source of MIB in SA-L2 Reservoir. The peak season for benthic growth and secondary metabolite production was observed in spring. Proportionally, 35% of the variability in water geosmin concentrations can be explained by benthic actinobacterial and cyanobacterial activity, showing that freshwater benthic mats represent a significant source of taste and odour compounds.
Latitude and lake size are important predictors of over‐lake atmospheric stability
Publisher: American Geophysical Union (AGU)
Date: 05-09-2017
DOI: 10.1002/2017GL073941
Assessing granular media filtration for the removal of chemical contaminants from wastewater
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.WATRES.2011.04.005
Abstract: Granular media filtration was evaluated for the removal of a suite of chemical contaminants that can be found in wastewater. Laboratory- and pilot-scale sand and granular activated carbon (GAC) filters were trialled for their ability to remove atrazine, estrone (E1), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR) and N-nitrosodiethylamine (NDEA). In general, sand filtration was ineffective in removing the contaminants from a tertiary treated wastewater, with the exception of E1 and EE2, where efficient removals were observed after approximately 150 d. Batch degradation experiments confirmed that the removal of E1 was through biological activity, with a pseudo-first-order degradation rate constant of 7.4 × 10(-3) h(-1). GAC filtration was initially able to effectively remove all contaminants although removals decreased over time due to competition with other organics present in the water. The only exception was atrazine where removal remained consistently high throughout the experiment. Previously unreported differences were observed in the adsorption of the three nitrosamines, with the ease of removal following the trend, NDEA > NMOR > NDMA, consistent with their hydrophobic character. In most instances the removals from the pilot-scale filters were generally in agreement with the laboratory-scale filter, suggesting that there is potential in using laboratory-scale filters as monitoring tools to evaluate the performance of pilot- and possibly full-scale sand and GAC filters at wastewater treatment plants.
Emerging Challenges for the Drinking Water Industry
Publisher: American Chemical Society (ACS)
Date: 18-02-2014
DOI: 10.1021/ES405606T
The effect of salinity on the germination of Ruppia tuberosa and Ruppia megacarpa and implications for the Coorong: A coastal lagoon of southern Australia
Publisher: Elsevier BV
Date: 11-2013
Fish productivity in the lower lakes and coorong, Australia, during severe drought
Publisher: Informa UK Limited
Date: 03-07-2015
DNA extraction from benthic Cyanobacteria: comparative assessment and optimization
Publisher: Oxford University Press (OUP)
Date: 06-12-2017
DOI: 10.1111/JAM.13332
Abstract: Benthic Cyanobacteria produce toxic and odorous compounds similar to their planktonic counterparts, challenging the quality of drinking water supplies. The biofilm that benthic algae and other micro-organisms produce is a complex and protective matrix. Monitoring to determine the abundance and identification of Cyanobacteria, therefore, relies on molecular techniques, with the choice of DNA isolation technique critical. This study investigated which DNA extraction method is optimal for DNA recovery in order to guarantee the best DNA yield for PCR-based analysis of benthic Cyanobacteria. The conventional phenol-chloroform extraction method was compared with five commercial kits, with the addition of chemical and physical cell-lysis steps also trialled. The efficacy of the various methods was evaluated by measuring the quantity and quality of DNA by UV spectrophotometry and by quantitative PCR (qPCR) using Cyanobacteria-specific primers. The yield and quality of DNA retrieved with the commercial kits was significantly higher than that of DNA obtained with the phenol-chloroform protocol. Kits including a physical cell-lysis step, such as the MO BIO Power Soil and Biofilm kits, were the most efficient for DNA isolation from benthic Cyanobacteria. These commercial kits allow greater recovery and the elimination of dangerous chemicals for DNA extraction, making them the method of choice for the isolation of DNA from benthic mats. They also facilitate the extraction of DNA from benthic Cyanobacteria, which can help to improve the characterization of Cyanobacteria in environmental studies using qPCRs or population composition analysis using next-generation sequencing.
Ocean urea fertilization for carbon credits poses high ecological risks
Publisher: Elsevier BV
Date: 06-2008
Predicted risks of groundwater decline in seasonal wetland plant communities depend on basin morphology
Publisher: Springer Science and Business Media LLC
Date: 25-09-2018
Elucidating the factors influencing the biodegradation of cylindrospermopsin in drinking water sources
Publisher: Wiley
Date: 23-01-2008
DOI: 10.1002/TOX.20356
Abstract: The cyanotoxin cylindrospermopsin (CYN) is produced by several species of cyanobacteria and can be persistent in drinking waters supplies, which is of major concern to water authorities because of its potential to severely compromise human health. Consequently, there is a need to fully understand the persistence of CYN in water supplies, in particular, to determine whether this toxin is readily degraded by endemic aquatic organisms. This study provides insights into the environmental factors that can influence the biodegradation of this toxin in Australian drinking water supplies. Biodegradation of CYN was only evident in water supplies that had a history of toxic Cylindrospermopsis raciborskii blooms. In addition, lag periods were evident prior to the onset of biodegradation however, repeated exposure of the endemic organisms to CYN resulted in substantial decreases in the lag periods. Furthermore, the concentration of CYN was shown to influence biodegradation with a near linear relationship (R(2) of 0.9549) existing between the biodegradation rate and the initial CYN concentration. Temperature was also shown to affect the biodegradation of CYN, which is important since CYN is now being detected in more temperate climates. The presence of copper-based algicides inhibited CYN degradation, which has significant implications since copper-based algicides are commonly used to control cyanobacterial growth in water bodies. The results from this study indicate that the biodegradation of CYN in natural water bodies is a complex process that can be influenced by many environmental factors, some of which include CYN concentration, temperature, and the presence of copper-based algicides.
Application of various oxidants for cyanobacteria control and cyanotoxin removal in wastewater treatment
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2014
Group cohesion and adherence in unstructured exercise groups
Publisher: Elsevier BV
Date: 05-2014
Rainstorms drive export of aromatic and concurrent bio-labile organic matter to a large eutrophic lake and its major tributaries
Publisher: Elsevier BV
Date: 02-2023
Spatial distribution of sediment nitrogen and phosphorus in Lake Taihu from a hydrodynamics-induced transport perspective
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.SCITOTENV.2018.09.145
Abstract: Hydrodynamics play an important role in sediment nutrient dynamics in large shallow eutrophic lakes. In this study, the spatial patterns of sediment nitrogen and phosphorus in Lake Taihu were compared from a hydrodynamics-induced transport perspective based on high-resolution investigation of sediment, field observations, numerical simulations and long-term ecological data analysis. The results showed that sediments were primarily distributed in the west and southeast portions of the lake. Additionally, the total nitrogen (TN) and phosphorus (TP) stored in the active sediments was 166,329 t and 67,112.4 t, respectively. The sediment TN content was 319.4-3123.8 mg kg
Environmental factors controlling colony formation in blooms of the cyanobacteria Microcystis spp. in Lake Taihu, China
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.HAL.2013.10.016
Abstract: Nitrogen (N) and phosphorus (P) over-enrichment has accelerated eutrophication and promoted cyanobacterial blooms worldwide. The colonial bloom-forming cyanobacterial genus Microcystis is covered by sheaths which can protect cells from zooplankton grazing, viral or bacterial attack and other potential negative environmental factors. This provides a competitive advantage over other phytoplankton species. However, the mechanism of Microcystis colony formation is not clear. Here we report the influence of N, P and pH on Microcystis growth and colony formation in field simulation experiments in Lake Taihu (China). N addition to lake water maintained Microcystis colony size, promoted growth of total phytoplankton, and increased Microcystis proportion as part of total phytoplankton biomass. Increases in P did not promote growth but led to smaller colonies, and had no significant impact on the proportion of Microcystis in the community. N and P addition together promoted phytoplankton growth much more than only adding N. TN and TP concentrations lower than about TN 7.75-13.95mgL
Lake‐size dependency of wind shear and convection as controls on gas exchange
Publisher: American Geophysical Union (AGU)
Date: 05-2012
DOI: 10.1029/2012GL051886
Multiple interception pathways for resource utilisation and increased ecosystem resilience
Publisher: Springer Science and Business Media LLC
Date: 12-2005
Water and climate change: Challenges for the 21st century
Publisher: IWA Publishing
Date: 03-2010
DOI: 10.2166/WCC.2010.100
Mixing potential of a surface-mounted solar-powered water mixer (SWM) for controlling cyanobacterial blooms
Publisher: Elsevier BV
Date: 12-2013
Rehabilitation of stream ecosystem functions through the reintroduction of coarse particulate organic matter
Publisher: Wiley
Date: 2009
In Search of Strategies to Mitigate the Impacts of Global Warming on Aquatic Ecosystems
Publisher: Wiley
Date: 20-11-2012
Integrated science informs forest and water allocation policies in the South East of Australia
Publisher: Informa UK Limited
Date: 03-07-2017
Determining the probability of cyanobacterial blooms: The application of Bayesian networks in multiple lake systems
Publisher: Wiley
Date: 2015
DOI: 10.1890/13-1677.1
Abstract: A Bayesian network model was developed to assess the combined influence of nutrient conditions and climate on the occurrence of cyanobacterial blooms within lakes of erse hydrology and nutrient supply. Physicochemical, biological, and meteorological observations were collated from 20 lakes located at different latitudes and characterized by a range of sizes and trophic states. Using these data, we built a Bayesian network to (1) analyze the sensitivity of cyanobacterial bloom development to different environmental factors and (2) determine the probability that cyanobacterial blooms would occur. Blooms were classified in three categories of hazard (low, moderate, and high) based on cell abundances. The most important factors determining cyanobacterial bloom occurrence were water temperature, nutrient availability, and the ratio of mixing depth to euphotic depth. The probability of cyanobacterial blooms was evaluated under different combinations of total phosphorus and water temperature. The Bayesian network was then applied to quantify the probability of blooms under a future climate warming scenario. The probability of the “high hazardous” category of cyanobacterial blooms increased 5% in response to either an increase in water temperature of 0.8°C (initial water temperature above 24°C) or an increase in total phosphorus from 0.01 mg/L to 0.02 mg/L. Mesotrophic lakes were particularly vulnerable to warming. Reducing nutrient concentrations counteracts the increased cyanobacterial risk associated with higher temperatures.
Changes in the photo-chemistry of Microcystis aeruginosa in response to light and mixing
Publisher: Wiley
Date: 18-03-2003
Pick your poison: do cyanotoxins or disinfection by-products pose the greater risk?
Publisher: Informa UK Limited
Date: 03-07-2019
CO2 alters community composition of freshwater phytoplankton: A microcosm experiment
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.SCITOTENV.2017.06.224
Abstract: The effects of CO
Assessment of riverine ecological condition in the fleurieu peninsula, South Australia: Implications for restoration
Publisher: Informa UK Limited
Date: 2010
Evaluating the effectiveness of copper sulphate, chlorine, potassium permanganate, hydrogen peroxide and ozone on cyanobacterial cell integrity
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.WATRES.2013.05.057
Abstract: Cyanobacterial blooms are continuously critical challenges in drinking water systems which can have various negative impacts such as production of taste, odour and toxic compounds. Furthermore, the intracellular metabolites could be released into surrounding waters when the cyanobacterial membranes are destroyed. Although a variety of techniques have been developed to control cyanobacterial blooms and remove cyanobacterial cells or metabolites in water treatment processes, the effect of these treatments on the membrane integrity of cyanobacterial cells have not been systematically studied and compared. This study evaluated the effectiveness of copper sulphate (CuSO4), chlorine, potassium permanganate (KMnO4), hydrogen peroxide (H2O2) and ozone on the cell integrity and densities of Microcystis aeruginosa. All of these technologies can compromise the cell membrane of cyanobacteria to varying degrees. Chlorine showed the strongest ability to impair the cell integrity with a majority (≥ 88%) of the cells compromised within the first minute and with the cell lysis rates ranging of 0.640-3.82 h(-1) during 1-60 min. Ozone dose of 6 mg L(-1) also could induce 90% lysis of the cyanobacterial cells in 5 min and the cell lysis rate of KMnO4 (10 mg L(-1)) was 0.829 h(-1). CuSO4 and H2O2 could not only destroy the viability of cyanobacterial cells but also showed algistatic potential over the 7 day treatment. The potential of all the oxidants (chlorine, KMnO4, H2O2 and ozone) considered as algicides were discussed in this study. The benefits and drawbacks of these control and water treatment options were assessed as well.
Extreme Climate Anomalies Enhancing Cyanobacterial Blooms in Eutrophic Lake Taihu, China
Publisher: American Geophysical Union (AGU)
Date: 07-2021
DOI: 10.1029/2020WR029371
Abstract: Climate warming in combination with nutrient enrichment can greatly promote phytoplankton proliferation and blooms in eutrophic waters. Lake Taihu, China, is a large, shallow and eutrophic system. Since 2007, this lake has experienced extensive nutrient input reductions aimed at controlling cyanobacterial blooms. However, intense cyanobacterial blooms have persisted through 2017 with a record‐setting bloom occurring in May 2017. Causal analysis suggested that this bloom was sygenerically driven by high external loading from flooding in 2016 in the Taihu catchment and a notable warmer winter during 2016/2017. High precipitation during 2016 was associated with a strong 2015/2016 El Niño in combination with the joint effects of Atlantic Multi‐decadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO), while persistent warmth during 2016/2017 was strongly related to warm phases of AMO and PDO. The 2017 blooms elevated water column pH and led to dissolved oxygen depletion near the sediment, both of which mobilized phosphorus from the sediment to overlying water, further promoting cyanobacterial blooms. Our finding indicates that regional climate anomalies exacerbated eutrophication via a positive feedback mechanism, by intensifying internal nutrient cycling and aggravating cyanobacterial blooms. In light of global expansion of eutrophication and blooms, especially in large, shallow and eutrophic lakes, these regional effects of climate anomalies are nested within larger scale global warming predicted to continue in the foreseeable future.
The interaction between climate warming and eutrophication to promote cyanobacteria is dependent on trophic state and varies among taxa
Publisher: Wiley
Date: 2014
Impact of copper sulphate, potassium permanganate, and hydrogen peroxide on Pseudanabaena galeata cell integrity, release and degradation of 2-methylisoborneol
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.WATRES.2019.03.082
Abstract: Frequent off-flavor events caused by geosmin and 2-methylisoborneol have caused concern among consumers about the quality of potable water. Pseudanabaena galeata, a filamentous cyanobacterium, is a known producer of 2-methylisoborneol in lakes and reservoirs. The use of algicides to control cyanobacteria must consider the potential release of contaminants into the water. This is the first study to systematically investigate the effectiveness of copper sulphate (CuSO
Algal esterase activity as a biomeasure of environmental degradation in a freshwater creek
Publisher: Elsevier BV
Date: 09-2002
DOI: 10.1016/S0166-445X(01)00254-5
Abstract: This study investigated the potential for using algal esterase activity of Microcystis aeruginosa and Selenastrum capricornutum as a rapid measure of the biological effects of acid mine drainage (AMD) in a South Australian stream (Australia) also affected by sewage pollution and dry-land salinity. Algal bioassays were based on the non-fluorescent substrate, fluorescein diacetate (FDA) which is metabolised by esterases to the fluorescent product, fluorescein. Esterase activity was interpreted as the mean rate of conversion of FDA to fluorescein and expressed as a percentage of the rate achieved by control algae (%FDAC). Flow cytometry was used to measure the fluorescence of in idual algal cells, enabling differentiation of three esterase activity states (low=S(1), normal and stimulated) and calculation of the percentage of algal cells in each activity state relative to that found for control algae (e.g. %S(1)). Algal esterase activity responded rapidly to AMD-affected water but also to increased conductivity (associated with dry-land salinity) and nutrient concentrations (associated with sewage). Exposure to AMD-affected water for 1 h reduced %FDAC by 30-70%, and increased %S(1) by 60-90%, a depression of esterase activity that was maintained over 24 h. A similar depression of esterase activity occurred in both algae exposed to comparatively high-conductivity water (ca. 20 mS cm(-1)) for 1 h but the algae recovered from this 'shock' within 24 h. The %FDAC of S. capricornutum increased from 66 to 158% of control values after a 24 h exposure to nutrient-enriched water s led downstream from a sewage treatment plant, despite the fact that the alga was grown in nutrient-sufficient culture. The combination of cyanobacterial (M. aeruginosa) and green (S. capricornutum) algal cultures with exposure times of 1 and 24 h was successful in distinguishing between the three types of pollution. Correlation of esterase activity measures with water quality parameters indicated that the clearest and least equivocal biological measure of AMD for the study area was the %S(1) for M. aeruginosa after a 24 h exposure. The use of the flow cytometer to define a low esterase activity state was therefore successful in clarifying the response to AMD-affected water. The study demonstrates the successful application of algal esterase activity bioassays, in combination with flow cytometry, to rapidly assess the toxicity of AMD-affected waters and to differentiate this response from the effects of other pollutants (increased nutrients and conductivity).
Modelling the effects of artificial mixing and copper sulphate dosing on phytoplankton in an Australian reservoir
Publisher: Wiley
Date: 03-2003
Separated adsorption and bacterial degradation of microcystins in GAC filtration
Publisher: Inderscience Publishers
Date: 2009
A comparison of phosphorus and DOC leachates from different types of leaf litter in an urban environment
Publisher: Wiley
Date: 12-08-2008
Physiology, blooms and prediction of planktonic cyanobacteria
Publisher: Springer Netherlands
Date: 2012
Myponga reservoir, South Australia: The influence of nutrients, phytoplankton, pathogens, and organic carbon on water quality
Publisher: Springer Netherlands
Date: 2012
Vertical distributions of chlorophyll in deep, warm monomictic lakes
Publisher: Springer Science and Business Media LLC
Date: 03-03-2010
Fish diets in a freshwater-deprived semiarid estuary (The Coorong, Australia) as inferred by stable isotope analysis
Publisher: Elsevier BV
Date: 09-2016
A multi-lake comparative analysis of the General Lake Model (GLM): Stress-testing across a global observatory network
Publisher: Elsevier BV
Date: 04-2018
Effect of chlorination on Microcystis aeruginosa cell integrity and subsequent microcystin release and degradation
Publisher: American Chemical Society (ACS)
Date: 09-05-2007
DOI: 10.1021/ES070318S
Abstract: The proliferation of cyanobacteria in drinking water sources is problematic for water authorities as they can interfere with water treatment processes. Studies have shown that oxidants such as chlorine can enhance the coagulation of cyanobacteria however, chlorine can potentially lyse cyanobacterial cells, releasing toxic metabolites. Chlorine also has the potential to effectively degrade these toxins. This study evaluated the effect of chlorine on the cell integrity of toxic Microcystis aeruginosa in reservoir water using flow cytometry. In addition, the effect of chlorine on the subsequent release and degradation of microcystin toxins was systematically assessed. Cell lysis occurred at chlorine exposure values between 7 and 29 mg min/L, which is within the range of normal disinfection practices. Intracellular toxin was shown to be released from damaged cells at a rate three times faster than it was degraded by chlorine. The degradation of extracellular microcystin by chlorine was found to be dependent upon the pH, chlorine exposure, and the presence of cyanobacterial cells.
Fate and transport of pathogens in lakes and reservoirs
Publisher: Elsevier BV
Date: 07-2004
Repair and revitalisation of Australia׳s tropical estuaries and coastal wetlands: Opportunities and constraints for the reinstatement of lost function and productivity
Publisher: Elsevier BV
Date: 07-2014
Variability in Dissolved Organic Matter Composition and Biolability across Gradients of Glacial Coverage and Distance from Glacial Terminus on the Tibetan Plateau
Publisher: American Chemical Society (ACS)
Date: 17-09-2019
Abstract: Globally, alpine glaciers hold a large quantity of dissolved organic matter (DOM) and are headwaters of numerous rivers supporting downstream heterotrophic metabolism. However, it remains unclear how glacial coverage and distance from the glacial terminus affect the fate of DOM. Here, we elucidate DOM variability in glacial-fed streams on the Tibetan Plateau using field s ling and bioincubation experiments and compare our findings with the existing literature. We found that dissolved organic carbon, DOM absorption
A Global Lake Ecological Observatory Network (GLEON) for synthesising high–frequency sensor data for validation of deterministic ecological models
Publisher: Freshwater Biological Association
Date: 2015
DOI: 10.5268/IW-5.1.566
Relating urban biodiversity to human health with the 'Holobiont' concept
Publisher: Frontiers Media SA
Date: 26-03-2019
Response of dissolved organic matter optical properties to net inflow runoff in a large fluvial plain lake and the connecting channels
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.SCITOTENV.2018.05.180
Abstract: Fluvial plain lake watersheds are usually highly urbanized and have high concentrations of chromophoric dissolved organic matter (CDOM). CDOM derived from the connecting urban channels usually share strong terrestrial and anthropogenic signals and net inflow runoff (Q
A generic, process-based model of microbial pollution in aquatic systems
Publisher: American Geophysical Union (AGU)
Date: 07-2008
DOI: 10.1029/2007WR006395
Repairing Australia's estuaries for improved fisheries production - What benefits, at what cost?
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/MF14041
Abstract: An Australia-wide assessment of ~1000 estuaries and embayments undertaken by the National Land and Water Resources Audit of 1997–2002 indicated that ~30% were modified to some degree. The most highly degraded were in New South Wales, where ~40% were classified as ‘extensively modified’ and % were ‘near pristine’. Since that review, urban populations have continued to grow rapidly, and increasing pressures for industrial and agricultural development in the coastal zone have resulted in ongoing degradation of Australia's estuaries and embayments. This degradation has had serious effects on bio ersity, and commercial and recreational fishing. A business case is developed that shows that an Australia-wide investment of AU$350 million into repair will be returned in less than 5 years. This return is merely from improved productivity of commercial fisheries of a limited number of fish, shellfish and crustacean species. Estuary repair represents an outstanding return on investment, possibly far greater than most of Australia's previous environmental repair initiatives and with clearly demonstrated outcomes across the Australian food and services economies.
Understanding the Impact of Biofilm Growth on Pipe Roughness
Publisher: American Society of Civil Engineers
Date: 05-2008
Effects of diurnal vertical mixing and stratification on phytoplankton productivity in geothermal Lake Rotowhero, New Zealand
Publisher: Freshwater Biological Association
Date: 07-2013
DOI: 10.5268/IW-3.3.625
Field Measurements of Mean Velocity Characteristics of a Large-Diameter Swirling Jet
Publisher: American Society of Civil Engineers (ASCE)
Date: 09-2010
Use of FDA and flow cytometry to assess metabolic activity as an indicator of nutrient status in phytoplankton
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/MF00048
Abstract: This study reports the use of a technique to determine nutrient limitation of cultured and natural phytoplankton. The technique, an FDA-activity assay, which is usually used to assess cell viability, was used to measure metabolic activity in response to nutrient addition the metabolic activity of phytoplankton was determined as the rate of hydrolysis of fluorescein diacetate (FDA), by intracellular esterases, to fluorescein, which was detectedusing a flow cytometer. Replacement of the limiting nutrient to nitrogen- or phosphorus-limited cultures and field populations resulted in an increase in metabolic activity that was detectable 24 h after nutrient addition. By flow cytometry, the natural phytoplankton community can be ided into different taxonomic groups the response of these to FDA could be determined in idually to allow identification of the nutrients limiting each type of phytoplankton. This would be more specific than the assessment of a whole-community response, which may mask subtle differences among taxa.
Impact of potassium permanganate on cyanobacterial cell integrity and toxin release and degradation
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.CHEMOSPHERE.2013.03.022
Abstract: Potassium permanganate (KMnO4) is commonly used as a pre-treatment oxidant to remove soluble manganese (Mn) and iron (Fe) which can contribute to dirty water in drinking water supplies. Because Mn and Fe problems are commonly associated with thermal stratification in summer and autumn, they frequently coincide with the presence of cyanobacteria. The use of KMnO4 as an oxidant for Mn and Fe control therefore needs to consider the potential impacts on cyanobacterial cell integrity and toxin release. This study aims to assess the effect of KMnO4 on cyanobacteria cell integrity, toxin release and toxin oxidation. A toxic strain of Microcystis aeruginosa was exposed to various concentrations of KMnO4 and the cell integrity of cyanobacteria was measured with flow cytometry. Further the intra- and extra-cellular toxin concentrations were quantified and it was apparent that KMnO4 reduced both the intra- and extra-cellular toxins at low initial concentrations of 1 and 3 mg L(-1) without complete cell lysis. However, the cell integrity of cyanobacteria was compromised at KMnO4 concentrations of 5 mg L(-1) and 10 mg L(-1) and led to intracellular toxin release. In the 10 mg L(-1) KMnO4 treatment, the total toxin was oxidised after 7h contact time. A model describing the two step process of release and degradation was developed and may provide a tool to assess the risk water quality posed by toxin release. Consequently, it may be possible to use KMnO4 as a pre-treatment for Mn and Fe at concentrations<3 mg L(-1) and short contact time when cyanobacteria are also present.
Relative Value of Surrogate Indicators for Detecting Pathogens in Lakes and Reservoirs
Publisher: American Chemical Society (ACS)
Date: 18-10-2005
DOI: 10.1021/ES050821+
Abstract: This study investigated the relative behavior of pathogens, fecal indicator organisms, and particles of varying size during transport through a reservoir following a storm event inflow in Myponga Reservoir, South Australia. During the inflow, s les were collected from the river and at various locations within the reservoir to determine the fate and transport of microroganisms as they progressed through the water body. Microbiological analysis included the indicator organisms Escherichia coli, enterococci, Clostridium perfringens, aerobic spores, and somatic coliphages, the protozoan pathogens Cryptosporidium spp. and Giardia spp., and the potential physical surrogates of pathogen contamination including particle size and turbidity. Of the microbial indicator groups, C. perfringens spores were the most highly correlated with Cryptosporidium spp. concentrations (Spearman Rho = 0.58), closely followed by enterococci (Spearman Rho = 0.57). Cryptosporidium spp. oocysts were predominantly associated with small sized particles (range of 14.3-27.7 microm). All of the microbial indicator groups tested were associated with larger sized particle ranges (> 63.3 microm) except C. perfringens spores which were associated with particles in the size range of 45.5-63.3 microm. Although indicators may rank correlate with Cryptosporidium spp., the variation in settling rates of different microorganisms has significant implications for the use of surrogates to estimate pathogen attenuation within reservoirs. For ex le, concentrations of Cryptosporidium spp. oocysts were reduced by a factor of 3 on reaching the dam wall, whereas enterococci were reduced by a factor of 10.
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