Schaffelke et al., 2001:

"Seagrass growth and productivity is adversely affected by high water turbidity, smothering by sediment or mud, high nutrient availability and the presence of herbicide residues."

AND 

"Terrestrial runoff is considered one of the most significant anthropogenic impacts on the water quality of the GBRWHA because it carries sediments, nutrients, heavy metals and other contaminants, acid sulfate soil leachate and litter."

AND

"Changes in water quality as a result of agriculture, urban expansion and industrial activities include increased exports to coastal waters of sediments, nutrients, and other contaminants such as heavy metals, organochlorine compounds, and polycyclic aromatic hydrocarbons (PAHs) (Fowler 1990; Tatsukawa et al. 1990; Brodie 1995;Connell 1993). These pollutant groups present a potential risk to dugongs and seagrass meadows."

AND

"Agriculture, mining, metal processing, and other industrial processes have the potential to release elevated levels of the toxic heavy metals (primarily arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium and zinc), via these processes, into the GBR lagoon. Also of concern is the mobilisation of heavy metals by acid leaching from oxidised acid sulfate soils (ASS) (section 2.3.5). Atmospheric transport of dust is also a possible pathway for heavy metals to be transported to the GBR lagoon (Rayment 1995)."

AND

"The close proximity of seagrass meadows to the coast means that they are likely to be affected by material originating from land and are vulnerable to changes in coastal processes. Seagrass decline, which is a global problem, has been linked to anthropogenic activities in coastal areas (Sheperd et al. 1989; Walker & McComb 1992; Dennison et al. 1993; Short et al. 1996). Seagrass and corals along the GBR coast have recruited, grown and evolved in the presence of natural freshwater,terrestrial nutrient and sediment inputs."

AND

"Short and Wyllie-Echeverria (1996) suggest that human activities are now the most serious cause of seagrass habitat loss. These include nutrient and sediment loading from agricultural runoff and sewage disposal, dredging and filling, urban stormwater, and land development. Seagrasses are also at risk of physical damage caused by human activities, such as trawling, certain fishing practices and anchor damage (Clarke & Kirkman 1989)."

AND
"Higher levels of contaminants and disturbances by dredging, channel maintenance and vessel traffic may be expected in DPAs in the vicinity of urban centres, industrial areas,ports, marinas, or dredged access channels. Regular vessel traffic in these areas has additional implications for dugong populations through increased potential for boat strikes and the evasion of dugong from feeding areas."

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Citation and/or URL

Schaffelke, B., Waterhouse, J. & Christie, C. 2001, A review of water quality issues influencing the habitat quality in Dugong Protection Areas.  Research Publication 66, Great Barrier Reef Marine Park Authority, Townsville, Australia.

Spatial Coverage

 Great Barrier Reef catchment and inshore environments

Temporal Coverage

2001

Update Frequency

Other Information

 None