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

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

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

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

Water Quality Comparison

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

Water Column Nutrients PrawnFarm STP Brisbane Moreton Bay Logan R NH 4 + (µM) NO 3 - /NO 2 - (µM) PO 4 3- (µM)

Chlorophyll a (µg l -1 ) PrawnFarm STP Brisbane Moreton Bay Logan R

Phytoplankton Productivity (mg C m -3 h -1 ) Prawn Farm STP Brisbane Moreton Bay Logan R

Tissue %N - Seagrass PrawnFarm STP Brisbane Moreton Bay Logan R

Amino Acid Profile - Seagrass Glutamine + Asparagine (nmol g-1 wet wt) PrawnFarm STP Brisbane Moreton Bay Logan R

 15 N - Seagrass PrawnFarm STP Brisbane Moreton Bay Logan R

Study Area

Study Sites

Sewage Effluent

Prawn Farm Plume

Water Quality Comparison

Water Column Nutrients

Chlorophyll a Map

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

Macroalgal  15 N Map

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