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The Pine estuary received a “D+” in the 2009
Report Card, a decrease in ecosystem health from the previous year
(“C”). This likely resulted from a number of high rainfall events
impacting the system during this reporting period as reflected in lower
median salinities for the estuary in 2008/2009.
The main reasons for the drop in Report Card
grade were small increases in the median turbidity and decreases in
median DO that reduced the proportion of 2008/2009 for which the estuary
was compliant with QWQ guidelines for these EHI indicators. Median
phytoplankton concentrations (Chl-a) were also
less compliant than in the previous year. These reductions in water
quality were only tempered slightly by a small increase in BHR in
relation to sewage nitrogen (δ15N). The
Pine failed to comply in 2009 with QWQ objectives for TP and was rarely
compliant for TN. Although nutrient concentrations remained high in the
Pine estuary, the median TP concentrations in 2008/2009 were some of the
lowest recorded since the inception of the EHMP for the middle and lower
reaches of the system.
Overall, 69% of the total Pine estuarine
riparian zone contains unmodified habitat although much of this is
limited to the intertidal (foreground) and lower and middle reaches of
the estuary. Behind the intertidal zone, unmodified habitat is
considerably sparser, with only the lower reaches supporting native
vegetation of mangroves and saltmarsh.
Abbreviations glossary |
Indicators and methods
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