158 | P a g e Conclusively, Studies using Survey Maps and Satellite Imageries during 1900 to 1985 reveal a trend of lowered ecological planning in development plans. In the recent past over 300 urban water bodies are of focus for conservation strategies at Bengaluru Urban Region. Hydrogeological investigations reveal that the ground water resources are contaminated. Dynamic Ground Water Resources investigations
emphasis appropriate attention as there is a decline of ground water resources. In this presentation hydrogeological conditions of Bengaluru Urban Region climate and rainfall, Geological Succession, soil and ground water condition, seasonal, ground water levels and Quality, Estimation methodology are reported. Non-Monsoon recharge from rainfall computed by RIP method is discussed. Water Chemistry interpretation Techniques are introduced. Climate resilient structural changes for Bengaluru Urban water security are identified and reported. Comparison between four global urban regions and Bengaluru case are compared and found that the inadequacy in planning and urban design need to be addressed. State of the art remote sensing techniques in assessing ground water at Bengaluru urban and action plan reveal an endangered ground water security.
159 | P a g e
What’s going on down (under) there? Unravelling biochemical flows under differential rainfall periods in a Western Australian calcrete
Mattia Saccò 1 , Alison Blyth 2 , Karina Meredith 3 , Colin Smith 4 , Quan Hua 3 , Debashish Mazumder 3 , William F. Humphreys 5 , Nicole White 2 , Kliti Grice 6
1. Applied Geology - Curtin University, PhD Student, Perth, WA, Australia 2. Applied Geology - Curtin University, Senior Lecturer, Perth, WA, Australia 3. ANSTO, Research Scientist, Sydney, NSW, Australia
4. Archaeology and History - La Trobe University, Associate Professor, Melbourne, VIC, Australia
5. Western Australia Museum, Research Scientist, Perth, WA, Australia 6. Curtin University, Professor, Perth, WA, Australia
Groundwater is a vital resource. It contains 97% of unfrozen water on the planet, playing a key role in present and future water needs for humanity. However, our knowledge about the ecosystem functioning is very poor, and groundwater environments are increasingly exposed to anthropic impacts and climate change- related processes. Novel biochemical (e.g. isotopic ecology) and genetic (e.g. eDNA) techniques, widely employed in fresh surface water studies, have the potential to unravel the complex dynamics shaping subsurface ecosystems, providing new insights to the small but quickly growing field of groundwater ecology. Stygofauna, together with microbes, are crucial actors in shaping and maintaining the organic matter (OM) cycles in environments characterized by low energy and scarce carbon availability. In order to understand groundwater ecological patterns, we investigate calcrete stygofaunal shifts linked with contrasting rainfall periods (low rainfall (LR), dry season; high rainfall (HR), wet season), through an interdisciplinary design composed of hydrology, isotopic ecology and genetics. Our results indicate that the inflow of rainfall under HR is responsible for increased nutrient concentrations in the system and dissolved organic carbon (DOC) pulses from the surface. Both the meiofaunal and stygofaunal communities’ benefit from these organic inflows, with gamma and proteobacteria the biota that fuels carbon and nutrients to the higher levels of the trophic web. The HR regime - and its subsequent terrestrial carbon incorporation - triggers a cascade effect driven by microbes (OM processors) and amphipods (biofilm grazers), which is finally transferred to the aquatic beetles (top predators). Overall, and in line with other work in the same research area, the inflow of rainfall triggered shifts towards more deterministic dynamics, revealing a complex web of interactions in a seemingly simple environmental setting. This study provides a preliminary untangling of the biochemical flows driven by rainfall in a calcrete aquifer. More investigations involving multidisciplinary approaches on other subsurface ecosystems, i.e. alluvial aquifers, will help to understand present ecological patterns and predict future scenarios in groundwaters.
Can metabarcoding provide insights into trophic web interactions underground: a case study from the Yilgarn region of Western Australia.
Nicole E. White 1 2 , Mattia Saccò 23 , William F. Humphreys 4 , Alison Blyth 2 3 1. Trace and Environmental DNA laboratory, School of Molecular and Life Sciences, Curtin
University, Perth, WA, Australia
2. Curtin University, Bentley, WA, Australia
3. WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
4. Subterranean Biology, Western Australian Museum, Perth, WA, Australia
160 | P a g e Objective: Subterranean ecosystems host a vital and highly adapted invertebrate aquatic biota which play a key role in sustaining groundwater ecological functioning and hydrological dynamics. However, functional biodiversity studies in groundwater environments, the vastest source of unfrozen freshwater on earth, are remarkably scarce.
Design and Methodology: To fill this gap, we propose to dig into the field of
groundwater trophic ecology via multi-locus metabarcoding analysis to potentially elucidate trophic web interactions (food webs) and the associated gut microbiome.
Stygofaunal specimens were collected from a well-known biodiversity hotspot, the Sturt Meadows calcrete in Yilgarn region of WA. Sampling campaigns were carried out during the dry (LR) and the wet (HR) seasons with the goal of comparing ecological trends within different rainfall conditions.
Results: Preliminary results on a small subset of samples support the possibility of opportunistic feeding of beetles on beetles (Paroster macrosturtensis, P.
mesosturtensis, P. microsturtensis) and the sharing of bacterial Families within the gut microbiome of these species, which may be associated with microbially-mediated carbon inputs (gamma and proteobacteria). Further work to expand on these
findings is currently underway. Metabarcoding results also highlighted scavenging as a driving force shaping beetles’ feeding habits.
Conclusion: This study, although in its infancy, may provide untangling of stygofauna food web dynamics and stress the importance of the synergy between microbes and invertebrates in calcretes. This is of importance to understand the groundwater functioning and model future affections linked with climate change such as aridification and loss of biodiversity.
All creatures great and small - a case study of stygofauna from an agricultural field site in Canterbury, New Zealand
Annette Bolton 1 , Louise Weaver 1 , Phil Abraham 1
1. Institute of Environmental Science and Research Limited (ESR), Ilam, Christchurch, New Zealand
Biologically, groundwater ecosystems remain one of the most understudied systems in New Zealand. As well as the nature of sampling methodologies and accessibility to suitable sampling sites, there are also challenges due to taxonomic capability.
However, information and new sampling techniques are rapidly being generated from this emerging area. We present a site-specific study from Canterbury, containing several wells from the same aquifer that have been sampled for biodiversity, including traditional and molecular techniques.
Objectives: To compare the biodiversity of several wells from the same aquifer and compare with environmental and sampling parameters.
Design and Methodology: Groundwater samples from a number of different wells from within the same aquifer were collected using a pump or hand netting method.
Samples were all collected on the same day across different seasons. Sub-samples were stored for water chemistry and stygofauna were identified using traditional and molecular techniques.
Original Data and Results: Biodiversity amongst several sites from the same aquifer is variable. There was a relationship between water chemistry and biodiversity.
161 | P a g e Sampling technique can bias the animals collected. Smaller animals are difficult to identify.
Conclusion: Our study suggests that several sites are required to sample
groundwater biodiversity and careful consideration of environmental parameters should be determined beforehand, to prescribe representative sampling locations.
Smaller meio-fauna, require further sampling protocols, and DNA-barcoding may be a more efficient way to measure their biodiversity.
Biological exchanges within the hyporheic zone: the importance of maintaining connectivity between surface and groundwaters
Kathryn L. Korbel 1 , Martin S. Andersen 2 3 , Helen Rutlidge 2 3 , Stefan Eberhard 2 4 , Grant C. Hose 1
1. Biological Sciences, Macquarie University, Sydney, NSW, Australia
2. Connected Waters Initiative Research Centre, UNSW, Sydney, NSW, Australia 3. School of Civil and Environmental Engineering, UNSW, Sydney, NSW, Australia 4. Subterranean Ecology, Coningham, TAS, Australia
Groundwater ecosystems are dependent on the input of oxygen, nutrients and organic matter from the surface. The hyporheic zone, the ecotone that connects surface and groundwaters, is a vital conduit for the supply of these nutrients to aquifers. The dynamics of exchange through this zone has a major influence on the biota and the overall health of both surface and groundwater ecosystem, particularly during low flow or drought, when groundwater discharged to streams maintains baseflow. However, surface -groundwater interactions are equally important to the ecosystems within aquifers during losing conditions. This study investigates how variations in surface-groundwater exchanges and connectivity influence the biotic communities in these freshwater ecosystems, using a combination of environmental DNA (eDNA) to characterise microbial and invertebrate communities and water chemistry (including nutrient, carbon and isotope data) to quantify the extent of SW- GW exchange. Samples were collected between 2015-2016 at three locations within the Maules Creek catchment, a sub catchment of the Murray-Darling Basin in NW NSW. At each site, samples were collected along a gradient from the creek through the hyporheic zone and into the adjacent alluvial aquifer. We found a rich diversity of invertebrates and microbes with distinct overlaps in biological communities noted along our gradients. Surface water microbes, distinguished by their ability to photosynthesise, were observed in highly connected aquifers, supporting the direction of water flow indicated by water chemistry data. Our results help
characterise biogeochemical processes within the hyporheic zone, highlighting the importance of this hydrological connectivity for surface and groundwater ecosystems.
Such findings will lead to a greater understanding of the connectedness of ground- and surface waters resulting in a more holistic view to water management within the Murray-Darling Basin, and elsewhere.
162 | P a g e
Development of a groundwater health index
Louise Weaver 1 , Judith Webber 1 , Phil Abraham 1 , Erin McGill 1 , Bronwyn Humphries 1 , Pierre-Yvres Dupont 1 , Annette Bolton 1
1. ESR Ltd, Ilam, Christchurch, Canterbury, New Zealand
Within groundwater there are a whole range of organisms from micro to macroscopic that live in a complex ecosystem. These ecosystems protect our groundwater by removing contaminants and maintain porosity and flow. The processes that occur in these systems is still largely a black box and there are many potentially vital
ecosystem services that occur that we still do not fully understand.
Objectives: Our project is aimed at ultimately establishing a groundwater health index that can be used, similar to the macroinvertebrate community index (MCI) in surface water systems. Our research is not only focused on the macroinvertebrates present but the microbial diversity as well.
Design and Methodology: Groundwater samples, in-situ biofilm bag samples have been collected at sites in New Zealand over multiple seasons. The water chemistry is analysed with the 16s rRNA sequence data (targeting bacteria, archaea, fungi, and eukaryotes) to provide the basis of a method to identify the status of a groundwater source.
Original data and results: We have shown there is a complex diversity present in both the groundwater itself and the attached microbial biofilm. We have shown this variation between the attached and groundwater occurs across all sites studied and significant differences in the Shannon richness indicator seen in Canterbury
(Wilcoxon rank, p = 4.6 x 10-7). We also find there are differences occurring in groundwater and attached microbial populations depending on the lithology and water chemistry present.
Conclusion: Our research is identifying key species (micro and/or macro) present that can potentially act as a tool for predicting the health of a groundwater. An additional benefit of understanding the biological processes that are occurring in our groundwater is that beneficial organisms capable of remediation could be discovered.
Novel Bioremediation strategies for nitrogen contaminated groundwater
Justin Morrissy 1 , Matthew Currell 1 , Andrew Ball 2 , Mallavarapu Megharaj 3 , Aravind Sirapaneni 4 , William McCance 5 , Suzie Reichman 5
1. School of Engineering, RMIT University, Melbourne, VIC, Australia 2. School of Science, RMIT University, Melbourne, VIC, Australia
3. Faculty of Science, University of Newcastle, Newcastle, NSW, Australia 4. South East Water Corporation, Melbourne, VIC, Australia
5. School of Engineering, RMIT University, Melbourne, VIC, Australia
Objectives: This study examined several lines of evidence to determine effective strategies for the remediation of the nitrogen-contaminated groundwater
surrounding a water treatment plant. Understanding the hydrogeology, chemistry and ecology and how they interact is essential to selecting an appropriate
bioremediation strategy.
163 | P a g e Design and methodology: To determine the most effective bioremediation strategy, statistical analysis was conducted on sampling data collected over >10 years in and around the water treatment plant. This allowed for further understanding of the hydrogeochemical site characteristics, to help inform the experimental phase. As a result, seven triplicate microcosms using the native groundwater ecosystem were established. The microcosms were used to test how inorganic electron donors at different concentrations affect the natural attenuation of nitrogen. Simultaneously, the effects of the different treatments on the microbial ecosystem were explored to determine any detrimental effects nitrogen plumes and the accompanying
remediation efforts may have on the groundwater ecosystems.
Original data and results: Multivariate statistical analysis of sampling data showed that iron concentrations were significantly correlated with total N and NH4+ but not NO3- (P-values of 2.54*10-14, 1.65*10-4 and 0.283 respectively) and sulphur was significantly correlated with NH4+ but not total N and NO3- (P-values of 6.54*10-7, 0.18, 0.05627 respectively). These correlations are consistent with an important role for redox in the behaviour of N contamination in the groundwater.
Conclusions: The findings of the statistical analysis of the sampling data show correlations between iron and sulphur concentrations and total nitrogen, NH4+ and NO3- concentrations. By combining these data with microcosm experimental results, we hope to delineate how different concentrations of these ions affect the natural attenuation of nitrogen-contaminated groundwater. This in turn can be used to design bioremediation strategies based upon biostimulation of the native ecosystem.