The Maroochy estuary Report Card grade dropped from a “C” in 2008 to a “D” in 2009.  This was due to a combination of factors including increases in turbidity and nutrient concentrations along with much reduced dissolved oxygen (DO) levels.  TN and total phosphorus (TP) were rarely compliant with QWQ guidelines throughout the system in 2008/2009.  Runoff from heavy rain during the reporting period was likely a driver for these enhanced nutrient concentrations which was reflected in some of the lowest salinities and highest turbidity’s found in this system since the beginning of the EHMP.  Although nutrient concentrations were elevated, the BHR for the Maroochy estuary improved as a result of the reduced extent of the sewage nitrogen (δ¹⁵N signal).

Overall, 59% of the total estuarine riparian zone of the Maroochy Estuary contains unmodified habitat, much of that in the intertidal zone. Only 33% of the riparian vegetation behind the intertidal zone remains unmodified with the predominant land uses being sugar cane and other agriculture in the upper reaches and residential in the lower reaches.

Abbreviations glossary | Indicators and methods

ECOSYSTEM HEALTH INDEX (EHI)

The EHI is a measure of the proportion of a reporting zone that complied with the water quality objectives for key indicators monitored as part of the Ecosystem Health Monitoring Program. The water quality objectives are defined in the South East Queensland Regional Water Quality Management Strategy (2001).

• EHI 1 = 100% of area complies with the environmental objectives.
• EHI 0 = 0% of the area complies with the environmental objectives.

BIOLOGICAL HEALTH RATING (BHR)

The Partnership's Scientific Expert Panel has endorsed a change to the BHR in 2006-07 which increase the BHR from 20% to 30% of the Report Card Grade.

The reason for the change is the implementation of the Riparian Assessment Program (RAP) which will comprise 15% of the total grade (half of the BHR). The other BHR indicators will make up the last 15%

The data from the riparian assessment is available as PDF document.