Marine plume water quality monitoring
Project staff: Michelle Devlin, Zoe Bainbridge, Stephen Lewis, Alan Mitchell, Jon Brodie, Mirjam Maughan and Dirk-Jan Bulsink
Project funding: Reef and Rainforest Research Centre (www.rrrc.org.uk) under the project 3.7.2 “Connectivity and risk: tracing materials from the upper catchment to the reef”
Project partnerships: ACTFR will work closely with Australian Institute of Marine Science, linking with their concurrent water quality programs and flood monitoring.
The primary aim of this project is to provide a comprehensive monitoring program, to effectively sample and assess the concentrations and transport of major land sourced pollutants. Sampling will be carried out by conventional grab sampling in flood waters originating from major rivers flowing in the Great Barrier Reef World Heritage Area. Conventional sampling in the flood plumes will be supplemented by additional sampling with water quality loggers at fixed sites within the plume affected areas, and depth profiling in and during the plume event.
Spatial analysis using GIS will be used to incorporate the flood extent maps derived from sampling from surface vessels along with satellite imagery and aerial over flights within the database. Analysis and reporting of all data will be provided as set out in the tender document, and we will look to report outcomes in integrated reports and scientific literature.
The research questions that we intend to investigate over the course of this monitoring program are as follows:
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Extent of exposure of reef ecosystems to terrestrially sourced materials, and further mapping of the extent of risk from these materials;
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The fate of dissolved and particulate materials in flood plumes (sedimentation, desorption, flocculation, biological uptake);
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Processing, dispersal and trapping of materials during flood events;
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Quantify the temporal dynamics of sediment dynamics, light availability and phytoplankton growth during and after plume events;
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Changes in phytoplankton assemblages during the duration of the plume event, and how this influences long term chlorophyll concentrations within the different regions.
Detailed approach:
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Deployment of 10 AIMS river loggers (see Mitchell & Furnas 2001) as close as practical to the mouths of the 10 priority rivers under Reef Plan (Normanby, Barron, N-Johnstone, Tully, Herbert, Burdekin, Pioneer, O’Connell, Fitzroy, Burnett). Deployment will be during each wet season from about November to May.
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Collection of surface and depth integrated water grab samples for the analysis of chlorophyll a, dissolved and particulate nutrients species, DOC, suspended sediment, salinity, pesticides and turbidity analysis in flood waters resulting from the first major flood in some of the following river (dependent on flood frequency)
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Dry Tropics Rivers
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Fitzroy River
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Burdekin River
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Wet Tropics Rivers – selected rivers depending on flood frequency in early 2008
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Pioneer River
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O’Connell River
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Herbert River
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Tully River
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Johnstone River
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Russell-Mulgrave River
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Barron River
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Flood-specific analysis of chlorophyll and turbidity data from 14 existing FLNTU instruments on inshore reefs (maintained under the Lagoon WQ monitoring component of Reef Plan MMP)
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Assessment and visual representation of flood plume distribution and transport using the King et al. (2002) hydrodynamic model (model domain covers the lagoon adjacent to the Burdekin River in the south to the Normanby River in the North). If provided by GBRMPA, the model output will be matched up with actual flood plume distribution maps from remotely sensed imagery.
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Correlation of environmental variables with phytoplankton communities within the flood plume gradient
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Visual representation of spatial flood plume distribution using the exposure model set out in Maughan et al., 2007.
