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| Photo coutesy
of KI NRM Board |
Introduction
Middle River is a fresh stream on the northern side of Kangaroo
Island. The site is on the upper reaches, just 5 km from its source
and well above the Middle River reservoir. Elevated turbidity
and nutrient levels are the most likely water quality problems.
The site is a wide, very deep, permanent pool, surrounded by native
vegetation. >> Map (272KB
PDF)
Water quality assessment
Water quality is assessed as being in good, moderate or poor
condition by interpreting water chemistry data in the context
of protecting environmental values. >>
More
Ecological health is assessed in spring and autumn. We use macroinvertebrates
for this purpose because they provide a relatively simple way
to assess the health of an aquatic ecosystem. >>
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Water chemistry is measured each month. We measure chemical indicators
because when they reach a certain level they can cause stress
or toxicity to animals and plants in an ecosystem. Some indicators
can also indicate if the water is suitable for drinking water
or for activities such as swimming. >>
More
Ecological health
We collect two samples of macroinvertebrates, one from riffle
(or flowing water) habitat and one from edge (still water) habitat.
The diversity of the macroinvertebrate community is used to describe
ecological health as being in good,
moderate or poor
condition.
Go
here to find out how we classify ecological health in streams.
Ecological health assessment for May 2006
| Habitat |
Ecological health
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| Edge |
Good
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| Riffle |
Habitat not present
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This site is usually in good condition, although since the site
is a deep pool, riffle habitat is usually not present.
In autumn 2006, the edge habitat had 31 different types of macroinvertebrates
present. The most common were oligochaete worms, amphipods (Austrochiltonia
australis), gripopterygid stoneflies and the midge Tanytarsus.
The most unusual finds at the site were mites in the family Limnesiidae,
the caddisfly Triplectides similis and the waterbug Sigara
truncatipala. Limited flow in recent years has promoted more
of an in-stream wetland habitat of isolated pools throughout much
of the upper reaches of this stream. The complex habitat of various
submerged and emergent aquatic plants provides considerable food
and shelter for a wide range of aquatic macroinvertebrates at
this site.
Download ecological health data
Water chemistry
The indicators that are measured in the Middle River are nutrients
(nitrogen and phosphorus), turbidity and salinity.
The concentrations of these indicators are used to classify the
water chemistry as being in good,
moderate or poor
condition, according to the needs of aquatic ecosystem protection.
Go here
to find out how we organise and classify the chemistry data.
Water chemistry classification for April to September 2006
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Indicator
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Classification
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Good
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|
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Good
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Good
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|
|
Good
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Good
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Nutrient and turbidity levels were all low during this period,
which could be related to lower than normal flows in the river.
Nitrogen and phosphorus are usually higher at this site in winter
months, when there is more runoff from the catchment. Nitrogen
can enter the river through runoff, which may contain fertilisers
or animal wastes. The Kangaroo
Island NRM Board has identified important issues that affect
water quality in this catchment and the Board is working with
landholders to address them.
>> Archived results
Download water chemistry graphs
Download raw chemistry data
What is being done to improve the condition
of South Australian rivers and streams
Efforts to improve the condition of South Australia's rivers
and streams are being driven by various government agencies, primarily
The Environment Protection Authority
The Department
of Water, Land and Biodiversity Conservation
Natural
Resource Management Boards
Department
for Environment and Heritage (SA)
Collaborative projects and programs being run by these agencies
are based on the protection of environmental values, as explained
in the National
Water Quality Management Strategy. >>
More
This page was last modified 25-09-2007
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