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Key Knowledge: Past initiatives by Australian agricultural and/or horticultural industries to control a threat or problem, including examples leading to both successful outcomes and to unforeseen consequences
Key Knowledge: Past initiatives by Australian agricultural and/or horticultural industries to control a threat or problem, including examples leading to both successful outcomes and to unforeseen consequences
Agriculture is a constant balancing act with nature. When a threat appears that could upset this balance (like a pest, a disease, or a landscape change), the industry launches an initiative, which is what we call any planned response or solution. However biological systems are complex. A solution that solves problem A might accidentally create problem B. In this lesson, we look at some of the triumphs and the cautionary tales of Australian farming history.
National Archive Photo: Rabbits around a waterhole during a Myxomatosis trial
When an initiative is based on deep research and careful rollout, it can save an entire industry.
When an initiative is based on deep research and careful rollout, it can save an entire industry.
The Control of Rabbits (Myxomatosis & Calicivirus)
The Control of Rabbits (Myxomatosis & Calicivirus)
The Threat: European rabbits were stripping the Australian landscape bare, causing massive soil erosion and competing with livestock for food.
The Initiative: The release of the Myxoma virus in the 1950s was the world's first successful biological control of a mammalian pest.
The Successful Outcome: Rabbit populations dropped by over 90% in some areas. This allowed native vegetation to recover and significantly increased the carrying capacity of sheep and cattle farms. It remains one of Australia's greatest agricultural wins.
Key Skill: evaluate the success of past initiatives in the management and/or eradication of threats to Australia’s food and fibre production
Key Skill: evaluate the success of past initiatives in the management and/or eradication of threats to Australia’s food and fibre production
PRACTICE Visit this National Archive page, read the section headed "Educational Value" and answer the following questions:
Describe the specific ways rabbits changed the Australian landscape. In your answer, explain how their feeding habits led to soil erosion.
Western Australia built rabbit-proof fences in 1902.
a. Based on the text, was this initiative successful or unsuccessful?
b. Identify one other "manual" method of control mentioned that colonists used before biological trials began.
The trials at Wardang Island were conducted by the CSIR (now CSIRO). Describe the innovative process used in this trial (what did the scientists actually do to the rabbits?).
The text states that myxomatosis reduced rabbit numbers from 600 million to 100 million in just two years, but later mentions that rabbits became resistant.
a. Evaluate the long-term effectiveness of myxomatosis as a permanent solution.
b. How did the Australian agricultural industry respond once the effectiveness of myxomatosis began to decline in the 1990s?
Use the marking scheme to evaluate your work
The Stump Jump Plough. From the collection of the State Library of South Australia
Just a few of the other successful innovations in Australian farming:
Just a few of the other successful innovations in Australian farming:
And the unforseen consequences...
And the unforseen consequences...
In 1900, the Australian sugar cane industry was under threat from the cane beetle. The adult beetles eat the leaves of the plant but the larvae attacked the roots which was a more serious problem. The cane beetle became so damaging to the industry that after several chemical methods failed to control the beetle, government entomologists introduced the cane toad from Hawaii in 1935.
Australia has no natural predators or diseases that can control the cane toad and it quickly became a pest due to its ability to breed all year round and to eat a wide range of foods includig insects, small mammals, other frogs, birds, pet food and household waste.
Cane Toad Bufo marinus Photo from the CSIRO website
The main points:
The main points:
The toads preferred eating other native insects to the cane beetle.
Toads had no natural predators because of their poisonous skin, leading to the death of native quolls, snakes, and crocodiles.
The toads multiplied into the millions and are still spreading across Australia today, causing a massive ecological crisis.
PRACTICE with these exam-style questions. Once you are finished, don't forget to use the the marking scheme to evaluate your work
Define the term "unforeseen consequence" in the context of an agricultural initiative. (1 mark)
Identify one successful past initiative used to control a biological threat in Australia. (1 mark)
Describe how the introduction of the cane toad failed to meet its original objective. (3 marks)
Evaluate the success of the Myxomatosis initiative. In your response, consider both the short-term agricultural benefits and the long-term biological reality of the pest developing resistance. (6 marks)
Analyse why it is essential for modern agricultural scientists to conduct "Environmental Impact Studies" before launching a new initiative, using a past example of an unforeseen consequence to support your answer. (8 marks)
SAC/exam Tip:
SAC/exam Tip:
When you write about "unforeseen consequences," always link them back to the original goal. A high-scoring answer explains that the initiative failed not just because it caused a new problem, but because it often didn't even solve the old one (like the toads ignoring the beetles).
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