Haynes, 2001:

• "Document the concentrations of trace metals and pesticides in intertidal and subtidal sediments and/or seagrasses along the Great Barrier Reef coasts;
• Investigate the toxicity of widely distributed pesticides to common seagrass species;
• Document the concentrations of pesticides in carcases of dugong stranded along the Queensland coast; and
• Carry out a risk evaluation of pollutants to the Great Barrier reef environment in general and to local dugong in particular."

"Although population growth and expansion in Queensland has been rapid (a 27% increase between 1986 – 1996), the northern Queensland cost still remains relatively sparsely populated (Anon 1999). 

Only 700,000 of the State’s 2.9 million residents live in the coastal areas adjacent to the Great Barrier Reef World Heritage Area.  Despite this low population pressure, extensive land modification has occurred over the last 200 years since European settlement (Anon 1993).  Today, 80% of the land area of catchments adjacent to the Great Barrier Reef World Heritage Area support some form of agricultural production (Wachenfeld et al. 1998; Gilbert in press).  To place Queensland land-use and vegetation clearing activities into perspective, more than 50% of the State’s original 117 million hectares of woody vegetation has been cleared primarily for agricultural purposes since European settlement (Anon 1999). As a consequence, run-off resulting from land-based agricultural activities (cattle grazing, vegetation clearance and intensive cropping) is the primary influence on water quality in the Great Barrier Reef World Heritage Area (Bell 1991; Moss et al. 1992b; Anon 1993; Brodie 1997). 

Increased soil erosion is estimated to have resulted in a 3 – 4 fold increase in the export of sediment loads into the Great Barrier Reef environment over the last 140 years (Moss et al. 1992b; Neil 1997).  It is estimated that the total load of nutrient influx to reef waters (principally nitrogen and phosphorous) has increased by 30% during this time (Brodie 1997).  Most of this increase in nutrient export has occurred during the last 40 years, a consequence of agricultural expansion, and the more than three-fold increase in fertiliser usage by the agricultural industry over this time (Pulsford 1996).

Diffuse source pollutants originating from agricultural land clearly constitute the greatest chronic pollutant source influencing the Great Barrier Reef World Heritage Area.  Increased water sediment concentrations and turbidity have been demonstrated to have a range of effects on coral communities (Tomascik and Sander 1985; Muller-Parker et al. 1994; Ward and Harrison 1996) and under extreme situations, can result in coral reef community collapse (Smith et al. 1981; Lapointe and O’Connell 1989)."

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Citation and/or URL

Haynes, D. 2001, Pesticides and heavy metal concentrations: impacts on Great Barrier Reef sediments, seagrass and dugong (Dugong dugon), Ph.D. thesis, University of Queensland, Brisbane, Australia.

Spatial Coverage

Great Barrier Reef catchment

Temporal Coverage

 2001

Update Frequency

Other Information

 None