Introduction
The Tod River is a brackish to saline stream on the eastern side
of the Eyre Peninsula. It flows into the Spencer Gulf just north
of Port Lincoln. The Tod River is the only permanently flowing
waterway on the lower Eyre Peninsula and is one of the main sources
of potable water for the region. Elevated turbidity and nutrient
levels are the most likely water quality problems.
This site at Koppio is one of two being monitored on the Tod
River (the other is White Flat) and is
located in the upper section of the catchment, upstream of the
Tod River reservoir. Land use upstream of Koppio is primarily
grazing and cropping. There is minimal riparian vegetationand
patchy aquatic reed growth in the river. >>
Map (415KB 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
The 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. >>
More
Water chemistry is measured each month (or every 3 months in
remote locations). 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 June 2006
| Habitat |
Ecological health
|
| Edge |
Good
|
| Riffle |
Good
|
Edge and riffle habitats from the Tod River at Koppio, upstream
from the Tod Reservoir, are consistently rated in a good ecological
condition. Despite the brackish salinity (about 7,000 mg/L) of
the stream, there is a complex habitat that supports a wide range
of tolerant macroinvertebrates inhabiting the Tod River.
The edge habitat had 22 different types of macroinvertebrates
present in autumn 2006. The most common were nematodes (roundworms),
hypogastrurid springtails and oligochaete worms. The riffle had
28 types of macroinvertebrates and the most common species were
hydrobiid snails that included the introduced Potamopyrgus
antipodarum, worms and amphipods (Austrochiltonia australis).
The site lacked mayflies, odonates and leptocerid caddisflies
and (most notably)any waterbugs. Perhaps predation by large numbers
of introduced mosquito-fish that live in the in-stream pools may
account for the absence of waterbugs.
Download ecological health data
Water chemistry
The indicators that are measured in the Tod River at Koppio 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
|
Indicator
|
Classification
|
|
|
Good
|
|
|
Good
|
|
|
Good
|
|
|
Good
|
|
|
Good
|
Nutrient and turbidity levels were low during this period, such
that water quality was classified as good for all indicators.
The total nitrogen and total phosphorus concentrations tend to
be higher during the summer months due to the increase in phytoplankton
growth in the river. The minimal shading over the river and limited
extent of aquatic plants tend to favour algal growth.
>> 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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