A long term understanding of both water quality and biological indicators is essential for quantifying the impacts of wastewater discharge

Environmental protection policies in all Australian states specify environmental values associated with particular ecosystem types. Water quality objectives are comparatively more specific and easily assessed by monitoring... [ view full abstract ]

Environmental protection policies in all Australian states specify environmental values associated with particular ecosystem types. Water quality objectives are comparatively more specific and easily assessed by monitoring programs than biological or ecosystem quality objectives. Despite the known difficulties in quantifying ecological or biological impacts, the Australian and New Zealand Water Quality Guidelines recognize the importance of direct biological assessments where the ecosystem is a specified environmental value. Case studies of three submarine wastewater outfall monitoring programs will be presented to illustrate how long-term monitoring programs that integrate both water quality and biological monitoring provide an accurate picture of the nature, intensity and extent of ecological impacts. The case studies show that it is only through long-term knowledge of patterns in both water quality and benthic ecology that managers and regulators can fully understand the impacts of wastewater discharge.