Good Science Victorian Curriculum Year 7

CHAPTER 3: ECOSYSTEMS
Figure 3.16
The large‐tooth sawfish
is critically endangered
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Indigenous knowledge is helping
to manage sawfish populations
Sawfish are some of the world’s most endangered marine fish species.
Four of the world’s five species are found in the estuaries of northern
Australia. An estuary is an area where a freshwater river meets the
ocean, resulting in brackish, or slightly salty, water. Sawfish are a
euryhaline species, which means that they can live in water that varies
in salinity from fresh to very salty. Very few sharks and rays can do this.
The sawfish populations in Australia’s northern estuaries and rivers
have declined over the last 50 years, and the species are now protected.
Threats to the population include fishing, and barriers across rivers, such
as road crossings and dams, that limit the migration of the sawfish up
and down the river.
Many Indigenous groups have strong cultural connections to sawfish.
They know where and when to find the different species and have noted
their decline. Scientists can collaborate with these groups to determine
ways of protecting threatened sawfish populations. Indigenous
knowledge of past sawfish distribution combined with recent population
studies helps to determine strategies that will protect these species from
extinction.
What is one threat to sawfish populations?
Indigenous knowledge is being used
to manage ecosystems
There have been many successful strategies involving Indigenous
peoples’ ecological knowledge to manage ecosystems:
• The Great Barrier Marine Park Authority works closely with the
traditional owners of the land to manage and protect the Great
Barrier Reef.
• Indigenous communities are working with scientists to study the effect
feral cats have on ecosystems and to determine eradication methods.
• Indigenous researchers are working to conserve biodiversity in
urban areas.
What is one way that Indigenous ecological knowledge
is used to manage ecosystems?
CHECKPOINT 3.7
1 Describe what is meant by
sustainability in regards to
ecosystems.
2 List four benefits to an
ecosystem of controlled fires.
3 Identify two impacts
on ecosystems that do
not experience regular
slow‐burning fires.
4 Explain how returning to
a regular slow-burning fire
regime benefits Australian
ecosystems.
5 How is a sawfish different
from other sharks and rays?
6 Predict the impact on an
ecosystem if sawfish were
removed.
7 Explain why Indigenous
knowledge is useful to
scientists who are studying
current populations of sawfish.
CONNECTING IDEAS
8 Considering their incredible
knowledge of Australian
ecosystems, suggest other
areas of land and water
management that Indigenous
Australians could lead.
SUCCESS CRITERIA
I can identify two ways that
Indigenous Australians’
knowledge and/or practices
can be used to help in the
sustainable management
of ecosystems.
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