Water Quality

From catchment to reef

The rate of degradation of coral reefs and other tropical marine ecosystems is increasing as a consequence of human pressures (including input of pollutants such as sediments, nutrient and toxic compounds; exploitation of reefs for fish and other organisms, sand and rock), indirect pressures of global climate change (leading to coral bleaching), and pressures with unknown cause such as crown-of-thorns starfish outbreaks and coral diseases.
The Great Barrier Reef (GBR) is the largest system of coral reefs in the world and was declared a World Heritage Area in 1981. About 98% of the area of the Great Barrier Reef World Heritage Area (GBRWHA) lies within the Great Barrier Reef Marine Park. The Marine Park is managed as a multiple-use area under Commonwealth legislation. All activities inside the Marine Park, including tourism, fisheries, shipping, and the discharge of pollution, are carefully managed.

The Great Barrier Reef is intimately linked with the adjacent coastal river catchments, collectively called the GBR Catchment. The linkages of the so-called Catchment to Reef Continuum are not only downstream, but also involve migrations of many species such as fish, between coastal marine habitats and inland waterways and wetlands.

The water quality of the coastal zone of the GBR is adversely impacted by several human activities both on the catchment and in the coastal marine waters such as:

• vegetation clearing, especially of riparian vegetation along the banks of rivers and creeks;
• soil erosion and sediment run-off;
• acid waters leaching from acid sulfate soils, a common soil type along the Queensland coast;
• water pollution from inputs of fertilisers, pesticides, toxic chemicals, sewage, rubbish, detergents, heavy metals and oil;
• poor stormwater management;
• clearing, filling and draining of wetland areas;
• alteration to coastal ecosystems such as floodplains, estuaries and mangrove forests;
• alterations to the hydrodynamic regime by development and construction activities (in freshwater, estuarine, and marine areas);
• dredging of the seafloor and sea dumping of the dredge spoil.

Significant proportions of pollutants from the GBR catchment reach the waters of the GBR during the intense flood events that dominate north Queensland rainfall and river flows, e.g. nitrogen levels in flood plumes are between 10 to 100 times higher than ambient marine concentrations.

The coastal zone off the Wet Tropics Region between Cairns and Tully, and the Whitsundays region is the area at high risk from land run-off.

Even though shipping is not strictly a catchment-based industry, it is connected to catchment activities by port operations and commodity export activities. The risk to the GBRWHA is associated with pollution derived from normal ship operations (such as waste disposal, vessel sewage, introduction of marine pests through ballast water and hull fouling, toxic compounds released from anti-fouling paints) and pollution as a result of shipping accidents (such as vessel groundings and oil spills).

The GBR region is economically dependent on agriculture, manufacturing, and mining, except for Cairns City, Douglas, and Whitsunday Shires that have tourism as their major industry. Significant growth is projected for urban areas in Queensland’s coastal zone. As a consequence, local governments along the coast face the challenge of balancing the demands of economic development associated with changes in land use, associated with shifts in agricultural activity, urban and industrial expansion with maintenance of healthy local coastal ecosystems. An integral component of this is protection of local water quality and maintenance of aquatic habitats.

Impacts of impaired water quality entering the GBRWHA

Since the 1980s scientists have increased their research effort on water quality in marine, estuarine and fresh waters of the Great Barrier Reef region This research has shown that water quality and ecological integrity of the coastal area of Great Barrier Reef Worlds Heritage Area are being affected by material originating from a range of human activities, both on the land and in the water such as primary industries (agriculture, aquaculture), urban and industrial development. More information can be found in:

Land use and the Great Barrier Reef. CRC Reef Research Centre Brochure, June 2003

D. McB. Williams (2002) Review of Impacts of Terrestrial Run-off on the Great Barrier Reef World Heritage Area

D. Haynes (2001) Great Barrier Reef Water Quality- Current Issues.

The Independent Science Panel of the Reef Protection Interdepartmental Committee found that:

• Coral reefs at several inshore locations along the coast have been disturbed and remain in a disturbed state, showing characteristics consistent with impacts due to enhanced nutrient availability or sedimentation.
• Coral reefs adjacent the Wet Tropics region show significantly higher levels of most major water quality parameters (e.g. nutrients), dramatically lower coral cover and diversity, increased areas of abundant algae, apparent imbalances between previous reef development and current potential for reef growth (based on the absence of live corals and reduced coral recruitment), and the recent disproportionate loss of exceptionally large, ancient coral colonies (indicating recent conditions were at least temporarily worse than during past several centuries);
• The concentrations of nutrients in river plumes may cause harm to GBR ecosystems;
• There are detectable levels of herbicides (principally diuron) in coastal and intertidal sediments and seagrasses adjacent to catchments with high agricultural use, at levels potentially impacting on the health of seagrasses; and
• There is evidence from overseas demonstrating harmful effects of excess nutrients and sedimentation on reef systems. This evidence also shows that by the time widespread effects are obvious, the system would be almost irreparably damaged .

Management of water quality in the Great Barrier Reef World Heritage Area

The Great Barrier Reef Marine Park Authority (GBRMPA) operates in partnership with Commonwealth and Queensland Government agencies to ensure that the World Heritage values of the Great Barrier Reef are preserved and protected for future generations. The GBRMPA has an obligation to manage water quality impacts on the GBR Marine Park (GBRMP).

In 1990, the International Maritime Organisation (IMO) declared the GBR region a Particularly Sensitive Sea Area (PSSA), which allows the Australian Government to implement initiatives to manage shipping with an aim to minimise shipping incidents and the environmental impact of shipping activities on the GBRMP. The first such initiative was the implementation of compulsory pilotage in certain areas in the GBRMP.

Point sources of pollution such as sewage discharges, that may affect the waters of the Great Barrier Reef World Heritage (GBRWHA), are managed by the State of Queensland under the Queensland Environmental Protection Act 1994. Point source pollution can also be addressed at a regional or State level by setting water quality objectives and standards for receiving waters under the Environmental Protection (Water) Policy 1997. In 2003, only Trinity Inlet near Cairns, in Queensland has developed environmental values, water quality objectives and standards since the legislation was introduced. The State Coastal Management Plan (2001) requires sewage discharges into Queensland coastal waters to achieve appropriate nutrient removal by 2010, for islands by 2005, in areas where nutrients have been identified as being an environmental problem.

While point source discharges of pollutants to the GBR Marine Park can be adequately managed under the existing regime, the majority of pollutant inputs are sourced from the GBR Catchment, and are hence located outside the jurisdiction of the GBRMPA. The plenary rights for land and water management remain with the Queensland Government. However, developments that may have a significant impact on matters of National Environmental Significance, such as the values of the GBRWHA, may need approval under the Commonwealth Environment Protection and Biodiversity Conservation Act (1999).

The Reef Water Quality Protection Plan

In August 2002, the Commonwealth and Queensland Governments adopted a Memorandum of Understanding on developing practical actions to improve water quality and reduce impacts on the Great Barrier Reef Marine Park, recognising the need for a cooperative and precautionary approach to protect the GBR, involving all levels of government and stakeholders. In May 2003, the Queensland and Commonwealth Governments released for public consultation a draft Reef Water Quality Protection Plan (the Plan) for catchments adjacent to the GBRWHA; the final Plan is expected to be available late 2003. For more information and to download a copy of the draft Plan click here.

The goal of the Plan is to halt and reverse the decline in water quality entering the reef within 10 years by;

• Reducing diffuse sources of pollutants in water entering the GBR, and
• Rehabilitating and conserving areas of the Reef catchment that have a role in removing water-borne pollutants (e.g. wetlands)

Funding will be mainly sourced from the Natural Heritage Trust and, for the Burdekin-Fitzroy and Lockyer-Burnett-Mary catchments, from the National Action Plan for Salinity and Water Quality.

Actions fall under the following categories:

• Self-management approaches
• Education and extension
• Economic incentives
• Natural resource management and land use planning
• Regulatory frameworks
• Research and information sharing
• Monitoring and evaluation

The Plan will build on existing government policies and industry and community initiatives. It identifies actions that are predominantly low-cost measures to encourage good catchment management and to assist landholders to adopt best land management practices. The time frame for the Plan is 10 years.

Studies undertaken to support the Plan include a review by a panel of scientists formed to provide advice on water quality in and adjacent to the Great Barrier Reef and a Productivity Commission study on industries in the Great Barrier Reef Catchment and measures to address declining water quality.

Researchers will be integral to the success of the Plan, for example in designing new water quality monitoring programs both on the catchment and in the GBR lagoon, and in developing improved indicators to measure water quality. The Australian Cooperative Research Centres for the Great Barrier Reef World Heritage Area (CRC Reef) and for Tropical Rainforest Ecology and Management (Rainforest CRC) have commenced a joint research program to develop new protocols and tools to identify and mitigate water quality problems and to assess the health of aquatic ecosystems in the Wet Tropics and Great Barrier Reef World Heritage Areas. For more information on the ‘Catchment to Reef Program’ click here.