Key findings were:
- Water quality in the Hardy Inlet estuary deteriorated towards the upper estuary past Molloy Island.
- The condition of the lower estuary was ‘moderate to good’. The water column was well-mixed and oxygenated, and nutrient concentrations were low (except after heavy rainfall and flow events). Aquatic plant life was dominated by seagrass – a favourable habitat for fish and invertebrates. Phytoplankton blooms were infrequent. Nutrients from urban drainage may contribute to the excessive macroalgal growth that has periodically impacted the Augusta foreshore.
- The condition of the upper estuary was poor. Dissolved oxygen concentrations in the water were low and nutrient concentrations were high. Nutrients from catchment run-off, and from sediment nutrient release in the deep channels have affected water quality. Phytoplankton blooms were a frequent symptom of nutrient-rich conditions in the upper estuary.
