Great Barrier Reef Marine Park

​The Great Barrier Reef Marine Park includes the world’s largest coral reef ecosystem and covers an area of 344,400 km²​, extending south from the northern tip of Queensland in north-eastern Australia to just north of Bundaberg. The park was created in 1975 through the Great Barrier Reef Marine Park Act. 

Marine ecosystems require good quality water to remain healthy. Declining water quality is recognised as one of the most significant threats to the long-term health and resilience of the reef.

Management of the reef is the responsibility of the Great Barrier Reef Marine Park Authority (GBRMPA), in collaboration with the Queensland Government and traditional owners. Active management of the reef, guided by a range of plans, policies, regulations and legislation, is required to ensure its protection and long-term health.

GBRMPA has Water Quality Guidelines for the Great Barrier Reef Marine Park (2010)[2.22 MB, 107 pages] with set levels for specific pollutants, which when exceeded prompt managers to take action. The guidelines focus on levels of sediments, nutrients and pesticides — the main catchment run-off pollutants that affect water quality on the Great Barrier Reef.

Regional catchment-level water quality objectives are being implemented under Queensland’s Environmental Protection (Water) Policy 2009 for the Reef catchment.
A list of Great Barrier Reef basins that have catchment level water quality objectives include:

• Wet Tropics region including all waters of the Daintree, Mossman, Barron, Mulgrave-Russell and Trinity Inlet, Johnstone, Tully, Murray, Hinchinbrook Island and Herbert River basins
• Townsville region including all waters of the Black and Ross River basins, Cleveland Bay, Magnetic Island
• Mackay-Whitsundays region including all waters of the O'Connell, Pioneer and Proserpine River basins, Plane Creek and Whitsunday Island basins, Repulse Bay, the Whitsundays
• Capricorn and Curtis Coast region including all waters of the Styx, Shoalwater and Water Park Creek Basins, Keppel Bay, the Boyne, Calliope and Curtis Island Basins, including Gladstone Harbour, the Narrows, lower Fitzroy estuary
• Other basins include Cape York, Wet Tropics (coastal waters), Burdekin-Don-Haughton, Mackay-Whitsunday (coastal waters) and the Fitzroy region.

For waters of the Great Barrier Reef that are outside state coastal waters, the objectives from adjacent waters of the same type apply. For instance, mid-shelf water quality objectives for Michaelmas Cay would apply to the mid-shelf waters of Opal Reef.

Each of the regional schedule documents has a description of the data that have been analysed and outlines the decision process supporting the guidelines. The general approach is to use locally applicable data as a basis for deriving guidelines. The data for open coastal waters and further seaward waters are generally sourced from Australian Institute of Marine Science monitoring programs.

Guidelines values are derived from site data from within particular water bodies. These values were compared against the current water quality guidelines. Where local water quality data meet or exceed the guideline values, values were set to maintain this condition. Where data did not meet these guideline values, the 2010 guideline value was adopted (i.e. annual and seasonal means).

Benthic light guidelines that support seagrass growth have been implemented through these schedules. These are sourced from James Cook University and predecessor agencies. Light levels are specified as photosynthetic active radiation moving averages depending on seagrass species.