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Marine Botany The University of Queensland. 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. Acknowledgements.
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Marine Botany The University of Queensland 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
Acknowledgements • Brisbane River and Moreton Bay Wastewater Management Study (Task - DIBM) • Ian McLeod & Tom Taranto - CSIRO Marine Research
Aims • Develop 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 impacts
Experimental Design • Develop 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 body
Impacted Unimpacted Study Sites - Two Creeks Moreton Bay Brisbane Logan R Prawn Farm STP
10-20 5-10 1-2 Water Column Nutrients NH4+ (µM) NO3-/NO2- (µM) PO43- (µM) Moreton Bay Brisbane Logan R Prawn Farm 130 STP
10-20 5-10 1-2 Chlorophyll a (µg l-1) Moreton Bay Brisbane Logan R Prawn Farm STP
50-100 20-50 1-20 Phytoplankton Productivity (mg C m-3 h-1) Moreton Bay Brisbane Logan R Prawn Farm STP
2-3 1.5-2.0 1-1.5 Tissue %N - Seagrass 2.0 Moreton Bay Brisbane 2.4 2.0 Logan R 2.8 Prawn Farm 2.0 2.8 1.7 STP
Amino Acid Profile - Seagrass Glutamine + Asparagine (nmol g-1 wet wt) 17 Moreton Bay Brisbane 60 18 Logan R 22 Prawn Farm 19 20 10 STP
Moreton Bay Brisbane Logan R Prawn Farm STP d15N - Seagrass 5.0 7.1 5.6 6.8 8.0 7.8 4.7
Amino Acid Profile - Mangroves Glutamine + Asparagine (nmol g-1 wet wt)
Conclusions • Sewage effluent • higher in dissolved nutrients • proportionally more NO3- and PO43- • Prawn effluent • predominantly NH4+ • higher in chlorophyll a and total suspended solids • Bioindicators were responsive to nutrients from both prawn and sewage effluent. • Bioindicator parameters identified a greater geographical influence than traditional water quality • Location of discharge may be important in controlling the impacts