The Tallebudgera estuary received a “B” in the 2009 Report Card, the same ecosystem health grade as the previous year.  The major water quality change monitored from the system was an increase in phytoplankton abundance in the upper reaches such that the estuary was only 58% compliant for QWQ guidelines for Chl-a whereas in the previous year it had been fully compliant.  However, this deterioration in one EHI indicator was partly offset by a slight improvement in DO concentrations throughout the estuary (58% compliance in 2008/2009 compared with 32% in 2007/2008).  As in previous years, the Tallebudgera estuary was fully compliant with QWQ guidelines for turbidity.

Overall, 50% of the Tallebudgera riparian zone contains unmodified habitat which affects its BHR and subsequent Report Card grade.  Much of the natural habitat is distributed in patches in the intertidal zone throughout the estuary and within the conservation and environmental parks in the middle reaches.  Much of the natural habitat in the remainder of the estuary has been removed or heavily modified to make way for canal developments.  The BHR for the system also declined slightly because sewage nitrogen levels (δ¹⁵N) were slightly increased from the previous reporting period.

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.