A novel toolbox for development of a Groundwater Health Index

Transcription

1 A novel toolbox for development of a Groundwater Health Index Louise Weaver, Phil Abraham, Judith Webber, Jenny Draper, Annette Bolton, Erin McGill, Beth Robson, Susan Lin, Bronwyn Humphries, Brent Gilpin, Murray Close

2 Why?

3

4 What lurks beneath your feet? Friend or foe?? Predators Scavengers Filter feeders Grazers/ detritivores Bacterial/ fungal biofilm Organic matter from surface

5 The Groundwater Health Index: Toolbox approach Communities can no longer protect drinking water from contamination Communities are stressed and moving towards the tipping point ie no protection of drinking water Communities are functioning well and not affected by contamination or no significant contamination is present

6 Canterbury Aquifers micro & macro-faunal communities

7 Sampling techniques 1. Develop sampling methods to recovery sufficient DNA to obtain high quality NGS libraries for each aquifer environment. 2. Subsurface difficult to access and sample, previous pumping of GW under represents MC s 3. Investigated the following sampling methods: i. ZIS sampler (best access to sediments) ii. in-situ biofilm bags (whole GW ecosystem) iii. down well sonication (future research)

8 ZIS sampler

9 In-situ biofilm bag sampler

10 In-situ sampler installed in well ground surface installation and placement lines unsaturated zone water table saturated zone well screen perforated upper casing packed with x5 gravel bags weighted lower housing insitu-biofilm and stygofauna sampler positioned in well screen

11 Field sites Crossbank Christchurch Scott s Burnham Raywell Rakaia ZIS Wells/Site Depth Catchment Recharge source Crossbank wells 1 & m Lower Alpine River Burnham wells 8 & m Mid Land surface Scotts Rd wells 1 & m Upper Foothill River Raywell farm wells 1 & m Lower Foothill River MAXIMUM NITRATE NITROGEN CONCENTRATIONS

12 Sampling Quarterly sampling: Groundwater levels Water chemistry Field parameters Water chemistry for 22 determinands, including major ions, metals and nutrients Groundwater, biofilm bags and Stygofauna Summer and Winter Lab analysis and water chemistry Seasonal data on the microbial communities and their subsurface environment

13 GW Chemistry Results

14

15 Nitrate and dissolved oxygen (DO) readings per year at Canterbury sites July-July Site Well ID Mean Nitrate-N g/m3 Min Nitrate- N g/m3 Max Nitrate-N g/m3 Mean DO mg/l Min DO mg/l Max DO mg/l Scotts Road SR Scotts Road SR Raywell Farm RF Raywell Farm RF Burnham B Burnham B Crossbank CB Crossbank CB Scotts Road SR Scotts Road SR Raywell Farm RF Raywell Farm RF Burnham B Burnham B Crossbank CB Crossbank CB Scotts Road SR Scotts Road SR Raywell Farm RF Raywell Farm RF Burnham B Burnham B Crossbank CB Crossbank CB

16 Laboratory analyses Biomass Heterotrophic plate counts (HPC) Protein concentration Enzyme activity Carbon, nitrogen and phosphorous acquisition Targeted metagenomics DNA was extracted from all samples and sent for next generation sequencing using the Illumina platform Used 16S, 18S rdna genes and ITS amplicons to target Prokaryotes, Eukaryotes and Fungi. Analysis performed using QIIME

17 Biomass HPC - Summer HPC - Winter HPC - culture of microorganisms Log 10 cell per ml Log 10 cell per ml that use organic carbon sources to grow Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank Site Site Protein - Summer Protein - Winter µg per gram dry gravel µg per gram dry gravel Protein assay - determines total protein concentration within a sample 0.0 Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank Site Site

18 Carbon acquisition Glucosidase - Summer Glucosidase - Winter Glucosidase - breakdown of pmol per hr per µg protein pmol per hr per µg protein complex carbohydrates Scotts Rd Raywell Burnham Crossbank Site Glucosaminidase (NAG) - pmol per hr per µg protein NAG - Summer NAG - Winter degrades chitin from higher organisms 0.0 Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank Site pmol per hr per µg protein Site Site

19 Phosphorous and nitrogen acquisition Phosphatase - Summer Phosphatase - Winter Phosphatase - Phosphorus pmol per hr per µg protein pmol per hr per µg protein mineralization Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank Site Site LAP - Summer LAP - Winter Leucine peptidase (Lap) - pmol per hr per µg protein degrades proteins into amino acids 0.0 Scotts Rd Raywell Burnham Crossbank Scotts Rd Raywell Burnham Crossbank pmol per hr per µg protein Site Site

20 Metagenomics results thousand reads per sample High diversity seen in all samples 300->600 different species Predominantly Proteobacteria (~25-70%) Groundwater higher 50-70% Biofilm more variable 25-50%

21 Site comparisons At all sites: GW high abundance Beta Proteobacteria (yellow) Biofilms Wide range species Some differences between sites Good! Groundwater ZIS biofilm Burnham biofilm

22

23 Stygofauna ID Taxonimic ID Graham Fenwick (NIWA) & Annette Bolton (ESR) Molecular ID targeted approach in development Preliminary results look promising we can identify Isopoda and Amphipoda using molecular approaches More to come!

24 The toolbox Communities can no longer protect drinking water from contamination Communities are stressed and moving towards the tipping point ie no protection of drinking water Ca 2+ Ca 2+ Mg 2+ meq/l Na + +K + CATIONS Canterbury groundwater 1.0 HCO 3 - SO 4 2- ANIONS Major ion chemistry Cl - meq/l meq/l HCO Communities are 3 functioning well and not Cl affected by contamination - 2- SO 4 or no significant ANIONS contamination is present Ca 2+ Mg 2+ Na + +K + CATIONS Waimakariri River 500 HCO 3 - Burnham biofilm Mg 2+ Na + +K + CATIONS sea water Cl - SO 4 2- ANIONS

25 Conclusions & next steps Differences seen in microorganisms between sites now comparing to GW chemistry Preliminary results Stygofauna ID from DNA - promising Where next: Expanding approach to Archaea, fungi and Stygofauna (GW macroinvertebrates) Whole community assessment Developing methods for activity assessment (proteomics, metabolomics) Ultimate goal Groundwater health index

26 Thank you for listening!