| Key indicators |
Indicator compliance |
% compliance |
|
|
0 |
|
|
0 |
|
|
76 |
|
|
0 |
|
|
0 |
| ■ <0.5 × water quality objective |
| ■ 0.5-1.0 × water quality objective |
| ■ 1.0-1.5 × water quality objective |
| ■ ≥1.5 × water quality objective |
|
The Report Card grade for the Bremer estuary was
an “F”, unchanged from the previous year. Although overall water
quality was poor in the Bremer, there were slight improvements in EHI
indicator grades mainly through large reductions in phytoplankton
abundance, especially in the upper reaches of the system. However,
offsetting this were reductions in DO throughout the estuary. As in
2007/2008, the Bremer was not compliant for nutrient concentrations (TN,
TP) and turbidity in 2008/2009. Turbidity throughout most of the system
was the highest it has been since the inception of the EHMP, likely
because of runoff from high rainfall events during the reporting period.
This was reflected in the low salinities that occurred along the
estuary with the lowest median values recorded since the EHMP began.
Although median TP concentrations remained well above QWQ guidelines,
in all except the upper reaches of the estuary they were also the lowest
concentrations measured since the inception of the EHMP.
The Bremer estuary only retains 44% overall
native riparian habitat, although nearly 90% of the foreground
(intertidal) habitat is still unmodified, considerably more than that of
the Brisbane River into which it flows. However, the background zone of
the Bremer has been extensively cleared for agricultural purposes with
only 4% of the system having unmodified habitat.
Abbreviations glossary |
Indicators and methods
|
