Best possible management practices to preserve and protect the Great Barrier Reef World Heritage Area (GBRWHA) are based on high quality scientific data and research.

The Great Barrier Reef Water Quality Current Issues report (released in September 2001) provided an overview of current issues and information concerning water quality in the GBRWHA. The Great Barrier Reef Water Quality Current Issues report identified land-based run-off from agricultural activities in the Great Barrier Reef Catchments as one of the greatest threats to the health of the inshore ecosystems of the GBRWHA. More information on the impact of human activities on the Great Barrier Reef can be found in the Water Quality Pressures and Status in Sugar Catchments report prepared jointly by the CRC for Reef and CRC for Sugar.

A CRC Reef Research Centre consensus statement by Australia’s leading Great Barrier Reef World Heritage Area and catchment scientists entitled The current level of scientific understanding on impacts of terrestrial run-off on the Great Barrier Reef World Heritage Area states:

Run-off of sediment and nutrients to the Great Barrier Reef has increased several-fold as a result of past and current land-use practices. There is significant concern that coastal ecosystems in the Great Barrier Reef World Heritage Area (GBRWHA) are being adversely affected as a consequence of this increase.

Priority scientific research on water quality issues that impact the Great Barrier Reef currently funded by the Great Barrier Reef Marine Park Authority includes:

1. The Importance of Sediment Denitrification in the Nitrogen Budget of the Great Barrier Reef Lagoon

Contact: Dr. Bradley Eyre, (Southern Cross University)
Dr. David Haynes (GBRMPA)

Nutrient runoff from adjacent catchments has been highlighted as one of the major threats to the Great Barrier Reef. Nitrogen is typically the nutrient that controls primary production in marine coastal ecosystems and as such, is commonly implicated in the eutrophication of coastal waters. Denitrification is probably the most important nitrogen cycling pathway because it is one of the few natural processes that is capable of counteracting the process of eutrophication. Up to 60% to 80% of the external nitrogen load delivered to coastal ecosystems may be lost to coupled sediment nitrification-denitrification. Despite its importance, sediment denitrification has rarely been measured in the GBR Lagoon and as such, its importance to the nitrogen budget of the GBR lagoon has never been properly quantified. Expected project outcomes include:

• Estimates of sediment denitrification rates in the Great Barrier Reef Lagoon by directly measuring N2 fluxes;
• Determination of spatial and temporal variability in sediment denitrification rates, and the major environmental factors controlling this variability (including the impact of terrestrial sediment and nutrient loads); and
• Quantification of the importance of sediment denitrification in the Great Barrier Reef Lagoon nitrogen budget.

2. Development and evaluation of a real-time algal toxicity test (toxY-PAM) for field and laboratory testing of water pollutants

Contact: Dr Jochen Müller, (University of Queensland)
Ms Susan Bengtson-Nash, (University of Queensland)

Routine monitoring of toxic organic chemicals require very sensitive chemical analytical techniques. However, these techniques are very expensive, time consuming and are usually only used to quantify exposure to individual, previously characterized substances. Water is often polluted by mixtures of compounds which may act synergistically on organisms, such that the overall effect cannot be accurately predicted from the concentrations of the individual components. A new PAM (pulse amplitude modulated) fluorometer which is highly specialized for the detection of toxic substances in water has recently been developed (tox-YPAM). The instrument also allows rapid dose response assessment of chemicals and assessment of the toxicity of chemicals to algae. The toxY-Pam is also a practical instrument that can be used directly in the field since it is light, easy to handle and reliable. Outputs of the project are to:

• evaluate the sensitivity of a variety of algal species to selected chemicals and identify a relative sensitive species for both freshwater and marine water that can be easily cultured,
• to evaluate algal specific factors (light history, age, nutrient status) that influence the sensitivity of a given species and identify a means to control these factors, and
• to determine the sensitivity of the selected test species to a range of toxic chemicals (i.e. calibration data).

3. Long Term Chlorophyll Monitoring

Contact: Dr Miles Furnas (Australian Institute of Marine Science)

A long-term program was commenced in 1992 to measure changes in chlorophyll a concentrations in the Great Barrier Reef World Heritage Area waters. Concentrations of chlorophyll a are indicative of water column nutrient status. Expected project outcomes include:

• Quantification of regional and cross-shelf patterns of phytoplankton biomass in the Great Barrier Reef waters;
• Correlation of regional differences with nutrient input information from adjacent catchment areas;
• Determination of the extent of temporal variability (seasonal, event related) in phytoplankton biomass in Great Barrier Reef waters; and
• Monitoring the effectiveness of programs to reduce the terrestrial input of nutrients to the Great Barrier Reef World Heritage Area.

Filtering chlorophyll samples for the Long Term Chlorophyll Monitoring Program

4. Rapid Coral and Seagrass Stress Measurement Tool

Contact: Dr Ross Jones (University of Queensland)
Dr David Haynes (GBRMPA).

The Great Barrier Reef Marine Park Authority is in urgent need of a rapid, non-destructive method of assessing stress in coral reefs and seagrass beds. This is required to assess the impact of dredging, mooring placement, antifoulant deposition, harbour and marine construction and ongoing coastal development activities. Expected project outcomes include:

• Assessment of the utility of the PAM instrument as a field measure of coral health;
• Assessment of the relative toxicity of selected herbicides/insecticides (diuron, atrazine, chlorpyrifos) to symbiotic algae of common corals species (e.g. Stylophora pistillata, Acropora formosa and Porites cylindrica);
• Assessment of the toxicity of selected antifoulants (copper and tributyl tin) to symbiotic algae of common coral species (e.g. Stylophora pistillata, Acropora formosa and Porites cylindrica); and
• Assessment of the use of PAM to measure sediment and adsorbed pollutant stress to symbiotic algae of common coral species (Stylophora pistillata, Acropora formosa and Porites cylindrica) in situ using the PAM methodology.

5. Sources and bioaccumulation of toxicants in the water, seagrass, dugong ecosystem.

Contact: Dr Caroline Gaus (University of Queensland)
Dr Jochen Müller (University of Queensland)

The Queensland environment is known to be significantly contaminated with dioxins. Areas contaminated include the nearshore marine environment. Dioxins are also known to be a significant contaminant in Queensland dugong populations. As a consequence, dioxins represent one of the most significant potential threats to the Great Barrier Reef World Heritage Area. The extent and impact of this contamination is, as yet, undefined. Expected project outcomes include:

• Determine the distribution of dioxins in the Great Barrier Reef World Heritage Area;
• Identify pathways and factors governing the distribution of dioxins in the Great Barrier Reef World Heritage Area;
• Investigate bioaccumulation of dioxins in dugongs; and
• Development of a model of dioxin partitioning and movement in the Great Barrier Reef World Heritage Area.

6. Pollutant concentrations in Great Barrier Reef World Heritage Area cetaceans.

Contact: Dr David Haynes (GBRMPA)
Dr Jochen Müller (University of Queensland)

Protection of Great Barrier Reef World Heritage Area dugong and cetacean populations has been identified as a key management issue for the Great Barrier Reef Marine Park Authority. Coastal pollution by pesticides and heavy metals is a recognized threat to aquatic mammals, potentially causing immune response suppression and birth defects. Dioxins, dieldrin, DDT and a range of heavy metals are all present in the marine environment along the Queensland coast, and their potential impact on local marine populations is presently unknown. Expected project outcomes include:

• Documentation of body burdens of heavy metals and pesticides in Great Barrier Reef World Heritage Area cetaceans.

7. The effect of grazing management on soil and nutrient loss in the tropical savannahs of North Queensland.

Contact: Dr Peter O’Reagain (Queensland Department of Primary Industries & Fisheries)
Dr David Haynes (GBRMPA)

The majority of terrestrial sediments and nutrients deposited in the Great Barrier Reef World Heritage Area originate from the extensive grazing lands of the Queensland interior, with the quantity of sediments and nutrients lost from these grazing lands being strongly dependent upon land management practices. This project will measure loss of nutrients and sediments at both the small plot and mini-catchment scale in order to facilitate scaling up to at least the small catchment level of load exports to the sea. Close involvement of graziers with the project will, in conjunction with Integrated Catchment Management groups and property management planning courses increase the potential adoption of sustainable management practices by the grazing industry, reducing resource degradation and the downstream effects of grazing management. Expected project outcomes include:

• Document the effects of grazing and different grazing management strategies on soil and nutrient loss in the semi-arid savannas of north Queensland;
• Development of grazing management strategies that will minimise soil and nutrient loss and ensure the long-term sustainable use of rangelands; and
• Assessment of the economic cost of resource degradation by relating animal productivity to soil and nutrient loss under different grazing management strategies, allowing the trade-off between sustainability and economic productivity to be determined.

8. Elevated levels of dioxins in Queensland: Where do they come from?

Contact: Ms Joelle Prange (University of Queensland)
Dr Jochen Müller (University of Queensland)

The Queensland environment is known to be significantly contaminated with dioxins. Areas contaminated include the nearshore marine environment, agricultural regions under sugar cane production as well as areas that are remote from human activity. Dioxins are also known to be a significant contaminant in Queensland dugong populations. As a consequence, dioxins represent one of the most significant threats to the Great Barrier Reef World Heritage Area. The origin and extent of this contamination is as yet undefined. Expected project outcomes include:

• Identification of the extent of dioxin contamination in Queensland;
• Identification of the sources of dioxin transfer to the marine environment;
• Elucidation of dioxin formation mechanisms; and
• Identification of strategies to minimise dioxin formation.

9. Assessment of pollutant flux from catchments to the marine environment using time integrated passive sampling techniques (SPMDs), DGTs and conventional data loggers

Contact: Dr Jochen Müller (University of Queensland)
Dr Mike Ridd (University of Queensland)
Dr David Haynes (GBRMPA)

Deployment of DGT samplers, Osprey Reef, September 2000

A range of agricultural pollutants including insecticides, herbicides, heavy metals, sediments and fertilizers have been detected in nearshore reef environments along the Queensland coast. Traditional sampling methods only provide an approximation of the concentrations of the contaminants present, and provide no information about seasonal flux or total loads discharged to the Great Barrier Reef World Heritage Area. Additionally, there is no current information available about the relative loads of pollutants originating from lands under different agricultural practices (i.e. pristine, banana, sugar-cane, vegetables). This project will enable deployment of passive samplers and electronic data loggers in waterways below different agricultural land uses and at nearshore reef environments over extended time periods. This will allow accurate data on pollutant loads and fluxes from agricultural catchments to be obtained. Expected project outcomes include:

• Assessment of the utility of data loggers and passive water samplers to monitor water pollutants in nearshore reef and seagrass bed environments;
• Time integrated annual and seasonal data on concentrations and flux of pollutants (heavy metals, organochlorines and nutrients) from a key agricultural catchment (Johnston or Russell-Mulgrave catchment); and
• Time integrated data on water column concentrations of heavy metals, organochlorines, dissolved nutrient species, sediments and selected herbicides at a key nearshore reef environment.

Related Links

• View 'Research Priorities for the Management of the Great Barrier Reef Marine Park and World Heritage Area'