Great Barrier Reef overloaded with pollutants

Posted: 16 January 2002

The Australian Federal Environment Minister, Robert Hill, has recently released a ground-breaking scientific report addressing the effect of land use activities on water quality in the Great Barrier Reef World Heritage Area.

Senator Hill said the report is an historic initiative because it recommends specific end-of-river pollution targets for all 26 river catchments adjacent to the Great Barrier Reef, the world's longest reef.

Great Barrier Reef© Great Barrier Reef Marine Park AuthorityThe report finds that, over the last 150 years, there has been a significant increase in pollution discharged to the Great Barrier Reef lagoon.

Sediment loads have increased by 300 to 900 per cent, phosphate discharges have increased by 300 to 1500 per cent, the total nitrogen load has increased by between 200 and 400 per cent.

Pesticide residues, including heavy metals, are now being detected in tidal sediments.

The Water Quality Report was prepared by the Great Barrier Reef Marine Park Authority at the request of the Great Barrier Reef Ministerial Council, which is Chaired by Senator Hill and includes the Queensland Minister for the Environment and Commonwealth and Queensland Ministers for Tourism.

The group took into account monitoring data from the Australian Institute of Marine Science, the CRC for the Great Barrier Reef World Heritage Area and the Great Barrier Reef Marine Park Authority as well as the results of catchment discharge modelling from the National Land and Water Resources Audit.

Their report confirms that the pollutants are having an adverse effect on inshore ecosystems such as corals and seagrass.

"If not addressed, the decline in water quality could threaten not only the environment of the Great Barrier Reef but also the tourism and fishing industries that rely upon a healthy Reef. These industries inject more than a billion dollars a year into regional economies in Queensland," Senator Hill said. The report recommends individual river catchment targets for the year 2011. Catchments are identified as high risk, such as Johnstone, Herbert and Proserpine, through to lower risk such as Bloomfield and Shoalwater catchments.

If the recommended targets are met, pollution loads entering the Great Barrier Reef will be reduced. Sediment will be reduced by 38 per cent. Nitrogen will be reduced by 39 per cent. Phosphorus will be reduced by 47 per cent. Chlorophyll will be reduced by between 30 to 60 per cent and there will be a detectable reduction in heavy metals and pesticides.

Senator Hill said that the report highlights the need for the Queensland government to ensure sustainable management of activities in the river catchments adjacent to the Great Barrier Reef.

Senator Hill said, "End-of-river catchment targets for the next ten years have been set at realistic levels, recognising this is a first step designed to halt the decline in water quality. More ambitious targets will be required in the longer term if we are to reverse the overall decline in water quality over the last 150 years."

© Environment News Service (ENS) 2001. Republished with permission from ENS, online at: http://ens-news.com

Related links:

  • The report is available online at: http://www.gbrmpa.gov.au

  • An Australian Wonderland

  • Coral Atlas maps fast disappearing reefs