1. Bioindicators used to detect prawn farm and sewage effluent Adrian Jones, James Udy, Mark O’Donohue & William Dennison Department of Botany, The University of Queensland, Brisbane, Queensland, Australia Marine Botany The University of Queensland

2. Acknowledgements Brisbane River and Moreton Bay Wastewater Management Study (Task - DIBM)Brisbane River and Moreton Bay Wastewater Management Study (Task - DIBM) Ian McLeod & Tom Taranto - CSIRO Marine ResearchIan McLeod & Tom Taranto - CSIRO Marine Research

3. Aims Develop bioindicators to identify different biotic responses for prawn farm effluent versus sewage effluentDevelop bioindicators to identify different biotic responses for prawn farm effluent versus sewage effluent Use bioindicator responses to determine the extent of prawn farm and sewage impactsUse bioindicator responses to determine the extent of prawn farm and sewage impacts

4. Experimental Design Develop bioindicators by comparing two separate tidal creeks: - prawn effluent discharge only - sewage discharge onlyDevelop bioindicators by comparing two separate tidal creeks: - prawn effluent discharge only - sewage discharge only Use the identified responses in the bioindicators to detect sewage and prawn effluent discharging into the same water bodyUse the identified responses in the bioindicators to detect sewage and prawn effluent discharging into the same water body

5. Water Quality Comparison

6. Study Sites - Two Creeks PrawnFarm STP Brisbane Moreton Bay Logan R Impacted Unimpacted

7. Water Column Nutrients PrawnFarm STP Brisbane Moreton Bay Logan R NH 4 + (µM) NO 3 - /NO 2 - (µM) PO 4 3- (µM) 130 1-2 5-10 10-20

8. Chlorophyll a (µg l -1 ) PrawnFarm STP Brisbane Moreton Bay Logan R 1-2 5-10 10-20

9. Phytoplankton Productivity (mg C m -3 h -1 ) Prawn Farm STP Brisbane Moreton Bay Logan R 1-20 20-50 50-100

10. Tissue %N - Seagrass2.4 2.8 2.0 2.8 2.0 2.0 1.7 PrawnFarm STP Brisbane Moreton Bay Logan R 1-1.5 1.5-2.0 2-3

11. Amino Acid Profile - Seagrass Glutamine + Asparagine (nmol g-1 wet wt) 60 22 17 20 19 18 10 PrawnFarm STP Brisbane Moreton Bay Logan R

12.  15 N - Seagrass 7.1 6.8 5.0 7.8 8.0 5.6 4.7 PrawnFarm STP Brisbane Moreton Bay Logan R

13. Study Area

14. Study Sites

15. Sewage Effluent

16. Prawn Farm Plume

18. Water Quality Comparison

19. Water Column Nutrients

20. Chlorophyll a Map

21. Amino Acid Profile - Mangroves Glutamine + Asparagine (nmol g-1 wet wt)

22. Macroalgal  15 N Map

23. Conclusions Sewage effluentSewage effluent –higher in dissolved nutrients –proportionally more NO 3 - and PO 4 3- Prawn effluentPrawn effluent –predominantly NH 4 + –higher in chlorophyll a and total suspended solids Bioindicators were responsive to nutrients from both prawn and sewage effluent.Bioindicators were responsive to nutrients from both prawn and sewage effluent. Bioindicator parameters identified a greater geographical influence than traditional water qualityBioindicator parameters identified a greater geographical influence than traditional water quality Location of discharge may be important in controlling the impactsLocation of discharge may be important in controlling the impacts