Year 10 · Geography · Geographical knowledge and understanding
Environmental change and management
Learners investigate the causes and consequences of environmental change, using the Great Barrier Reef as an example, and evaluate management strategies.
Awaiting educator review. This material was drafted by our content team with AI assistance and is waiting for review by a qualified educator. Please check it suits your child before using it. Created 10 October 2026.
Learning goals
Learners will
- Explain the causes and consequences of an environmental change.
- Identify perspectives of different stakeholders.
- Evaluate management strategies using sustainability criteria.
Success looks like
- I can explain the human and natural causes of coral bleaching.
- I can describe how different stakeholders view an environmental issue.
- I can evaluate a management strategy using economic, social and environmental criteria.
The big idea
Environments change through natural processes and human activity. Geographers investigate the causes, consequences and management of change.
The Great Barrier Reef, off the coast of Queensland, is the world's largest coral reef system, stretching about 2,300 km. It is a World Heritage Area and the Sea Country of many Aboriginal and Torres Strait Islander Traditional Owner groups.
The main threat to the Reef is climate change. Higher sea temperatures cause coral bleaching. The Reef has experienced several mass bleaching events since 2016. Ocean acidification, caused by the ocean absorbing carbon dioxide, can weaken coral skeletons.
Other threats include poor water quality from agricultural runoff carrying sediment and fertilisers, outbreaks of crown-of-thorns starfish, coastal development and severe cyclones.
Different stakeholders have different perspectives: tourism operators, farmers, fishers, scientists, governments, conservation groups and Traditional Owners. Their world views shape what they think should be done.
Management strategies include reducing greenhouse gas emissions, improving farming practices to cut runoff, controlling crown-of-thorns starfish, zoning areas of the marine park, and Traditional Owner-led Sea Country management and ranger programs.
To evaluate a strategy, geographers use sustainability criteria: Is it environmentally effective? Is it economically viable? Is it socially fair? Does it address the cause, or only the symptoms?
Worked examples
Cause and consequence chain
Explain how fertiliser use on a sugarcane farm can harm the Reef.
- Excess fertiliser washes off farms in heavy rain (runoff).
- Nutrients flow down rivers to the Reef lagoon.
- High nutrients are linked to crown-of-thorns starfish outbreaks and algal growth.
- Starfish eat coral, reducing coral cover.
Answer: Fertiliser runoff increases nutrients that are linked to starfish outbreaks and coral loss.
Evaluating a strategy
Evaluate culling crown-of-thorns starfish as a management strategy.
- Environmental: protects coral at targeted high-value sites.
- Economic: costly and labour-intensive; cannot cover the whole Reef.
- Cause or symptom? It treats a symptom; reducing nutrient runoff targets a cause.
- Judgement: useful short-term at key sites, but must be combined with long-term action on water quality and climate.
Answer: Effective locally but limited; must be combined with strategies that address causes.
Practice check
Have a go, then check your answers. Each answer comes with an explanation.
Answer guide for parents
What is the main threat to the Great Barrier Reef?
Climate change — Rising sea temperatures from climate change cause mass bleaching.
What causes coral bleaching?
Stress, especially from high water temperatures — Heat stress causes corals to expel their algae.
Which is a stakeholder in Reef management?
A tourism operator — Tourism operators have a strong interest in Reef health.
Which strategy addresses a cause rather than a symptom?
Reducing fertiliser runoff — Reducing runoff tackles a driver of starfish outbreaks.
Who manages Sea Country programs along parts of the Reef?
Traditional Owners, often with ranger programs — Traditional Owner groups manage Sea Country, often in partnership with agencies.
About how long is the Great Barrier Reef, in kilometres?
2300 — The Reef stretches about 2,300 km along Queensland's coast.
A person or group with an interest in an issue is a ____.
stakeholder — Stakeholders have interests in outcomes.
Water flowing over land into waterways, carrying soil and fertilisers, is called ____.
runoff — Runoff carries pollutants to the Reef.
Watch out for
- Bleached coral is not necessarily dead; it can recover if conditions improve, but repeated bleaching reduces recovery time.
- Some think a single strategy can 'save' the Reef. Effective management combines global and local actions.
Tips for parents
- Present environmental debates with a range of stakeholder views and encourage evidence-based conclusions.
- Look for publicly available information from Traditional Owner organisations and Sea Country ranger programs to understand First Nations perspectives.
- Use official reef reports and scientific organisations for data rather than opinion pieces.
Go further
- Write a stakeholder role-play: a farmer, tourism operator, scientist and Traditional Owner discuss management options.
- Investigate an environmental change in your local area using fieldwork, such as water quality testing in a creek.
- Create a management plan for a local environment using sustainability criteria.