1. Water quality and river plume monitoring in the Great Barrier Reef: an overview of methods based on ocean colour satellite data Michelle Devlin 1, Caroline Petus 1, Eduardo da Silva 1, Dieter Tracey,1 TropWATER, James Cook University, Townsville

2. Overview The long-term goal of Reef Plan is to ensure that the quality of water entering the Great Barrier Reef from adjacent catchments has no detrimental impact on its ecosystem health and resilience Requires a monitoring and evaluation strategy that evaluates the efficiency and effectiveness of implementation and progress toward this goal. Monitoring activities under the Paddock to Reef Marine Monitoring Program include ambient and wet season water quality measurements, inshore coral and seagrass monitoring and herbicide detection.

3. GBR - Marine Monitoring Program Implemented in 2005 as part of the GBR Water Quality Protection Plan (2003) Inshore WQ monitoring Biological monitoring Flood plume monitoring In 2009 GBRMPA released the water quality guidelines for the Great Barrier Reef Marine Park that provide: Annual thresholds – chlorophyll, TSS, PN, herbicides triggers for management action where exceedances occurs; threshold levels for analysis of current condition and trend monitoring; RS – provide key source of information for GBR managers In 2009 GBRMPA released the water quality guidelines for the Great Barrier Reef Marine Park that provide: Annual thresholds – chlorophyll, TSS, PN, herbicides triggers for management action where exceedances occurs; threshold levels for analysis of current condition and trend monitoring; RS – provide key source of information for GBR managers

4. Overview Monitoring of river plumes now forms an integral component of the MMP. Difficult to evaluate the complex responses to changing water quality based on in-situ water quality data only

5. MODIS – KEY SOURCE OF DATA (SO FAR) MODIS DATA: Synoptic view of the ocean Daily observations from 2002 Resolution: 250 - 1000 m = S UBSTANTIAL BENEFITS I N ADDITION TO IN - SITU SAMPLING AND NUMERICAL MODELLING GREAT BARRIER REEF AUSTRALIA

6. MAIN PROJECT: Wet Season monitoring part of the Marine Monitoring Program MAIN OBJECTIVES: Mapping of flood plumes Modelling and summarizing land- sourced contaminants transport and light levels within river plume waters, and; Evaluation of the susceptibility of GBR key ecosystems to river plume exposure

7. MAIN PROJECT: flood plume monitoring part of the Marine Monitoring Program MAIN OBJECTIVES: Mapping of flood plumes Modelling and summarizing land- sourced contaminants transport and light levels within river plume waters, and; Evaluation of the susceptibility of GBR key ecosystems to river plume exposure 1.

8. Characteristic colour signatures of GBR plumes waters MODIS true color 6 Colour Classes MAPPING OF GBR FLOOD PLUMES AND PLUME WATER MASSES: using a supervised classification of MODIS true colour images Plume full extent GBR plume waters :

9. Example: Fitzroy plume water masses MOVEMENTS Map the MOVEMENTS of river plumes in the Great Barrier Reef Devlin et al., 2013

10. MODIS ocean colour imagery 2011 plume frequency map 1.Tully-Herbert 2.Fitzroy Alvarez-Romero et al., 2013 Devlin et al., 2013 Petus et al., 2014a Frequency: FREQUENCY Map the FREQUENCY of river plumes during the wet season

11. Connecting land based pollutants with marine water quality MAIN OBJECTIVES: Mapping of flood plumes Modelling and summarizing land- sourced contaminants transport and light levels within river plume waters. Evaluation of the susceptibility of GBR key ecosystems to river plume exposure 1. 2.

12. Objective 2. Models summarizing land-sourced CONTAMINANTS TRANSPORT AND LIGHT LEVELS within river plume waters Plume water masses = different concentrations & proportions of : land-sourced pollutants Optically Active Components RISK MODELS AND LIGHT MODELS - GBR COASTAL WATERS

13. RIVER PLUME’ RISK MODEL Petus et al., in Prep. Iresp = TSS / TSS thr + DIN / DIN thr + PSII / PSII thr Threshold values for ecosystem adverse response inhibition of photosynthesis / Coral reefs and Seagrass beds Metric summarizing the likely adverse effect of combined contaminants inside the plume waters

14. Kd(PAR) = [CDOM] + [CHL] + [TSS] Develop empirical models predicting light attenuation from the concentrations of TSS, CDOM, chl-a EMPIRICAL LIGHT MODEL Petus et al., in Prep.

15. Develop loading models based on river loads, rate of surface transport and true colour classes

16. http://www2.hawaii.edu/ remotely-sensed data in situ data Annual River Load

19. MAIN PROJECT: flood plume monitoring part of the Marine Monitoring Program MAIN OBJECTIVES: Mapping of flood plumes Modelling and summarizing land- sourced contaminants transport and light levels within river plume waters, and; Evaluation of the susceptibility of GBR key ecosystems to the river plume exposure 1. 2. 3.

20. Using MODIS data for understanding changes in seagrass meadow health and coral reefs… Critical for management Strong application of the true colour data over annual and multi- annual time scales Evaluation of the SUSCEPTIBILITY OF GBR KEY ECOSYSTEMS to river plume exposure

21. CORRELATION SEAGRASS HEALTH & Fp (turbid waters) Petus et al., 2014b Evaluation of the SUSCEPTIBILITY OF GBR KEY ECOSYSTEMS to river plume exposure

22. Progress risk model + risk assessment for the GBR ecosystems Analyze the results in relation to selected environmental factors Assess changes in exposure of the selected ecosystems to the 'river plume risk' Produce time series of GBR river plume risk maps Progress the combined adverse response index (Iresp) Conceptual model

23. Multiple products for wet season, plume monitoring and risk assessment

24. Himawari-8 – future applications for wet season monitoring Need for greater resolution of the small scale processes. Plume imagery can be difficult to retrieve during monsoonal weather conditions. Aggregate of images from Himawari-8 could provide critical information on plume fronts, transport and fate Immediate management applications if used in the context of monitoring inshore systems under the MMP.

25. RGB /true colour analysis – critical source of data for plume dynamics Correlation of true colour with in-situ water quality gradient can provide links to the GBR ecological systems RGB /true colour analysis – critical source of data for plume dynamics Correlation of true colour with in-situ water quality gradient can provide links to the GBR ecological systems Himawari-8 could provide information on: The relevant timescales associated with the variability associated with these transport processes greater certainty of obtaining a complete spatial and temporal picture over wet season. Himawari-8 could provide information on: The relevant timescales associated with the variability associated with these transport processes greater certainty of obtaining a complete spatial and temporal picture over wet season.

26. THANK YOU!