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Coasts: Opportunities and Hazards » Coral Reef Example: The Great Barrier Reef

What you'll learn this session

Study time: 30 minutes

Cambridge spec: 2.3.8

Where the Great Barrier Reef is and how big it is
Why the reef is important
The threats facing the reef
The strategies and techniques used to protect and manage it, and how well they work

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The example: the world's largest coral reef system

The spec asks for one detailed example of a named country or coastal area. Ours is the Great Barrier Reef in Australia. Earlier you learned about Coral Reefs: Importance, Threats and Protection in general. Here we apply those ideas to one real place, with named facts you can use in a 6-mark answer.

Location: the reef lies in the Coral Sea, off the coast of Queensland, in north-east Australia. Australia is an HIC.

Size: it stretches for about 2,300 km along the coast and covers more than 340,000 km². It is made up of thousands of separate reefs (about 2,900) and more than 900 islands. It is the largest coral reef system in the world and is so big that it can be seen from space.

Named places to use in an answer: the Cairns and Port Douglas area and the Whitsunday Islands are popular for tourism. Cairns is a main base for reef trips.

Quick timeline

1975: the Great Barrier Reef Marine Park is created and the Great Barrier Reef Marine Park Authority (GBRMPA) is set up to manage it.
1981: the reef is made a World Heritage Site.
1998 and 2002: the first two mass bleaching events.
2004: a new zoning plan comes into force.
2012: the crown-of-thorns starfish control programme begins.
2015: the Reef 2050 Plan is launched.
2016 and 2017: back-to-back mass bleaching.
2020, 2022 and 2024: more mass bleaching events.

Why the Great Barrier Reef is important

🐠 Environmental

Biodiversity: it is home to about 1,600 species of fish, about 400 types of hard coral, six species of marine turtle and many whales, dolphins and seabirds.
Coastal protection: the reef takes the energy out of waves before they reach the Queensland coast, so there is less erosion and flooding.
World Heritage Site: listed in 1981 because of its outstanding natural value.

💰 Economic and social

Tourism and jobs: the reef adds more than 6 billion Australian dollars a year to the economy and supports about 64,000 jobs, in dive boats, hotels, restaurants and airlines.
Fishing: commercial and recreational fishing depend on the reef as a nursery and feeding ground.
Culture: Aboriginal and Torres Strait Islander peoples have lived beside the reef for tens of thousands of years and it is part of their culture.

Threats to the Great Barrier Reef

Threat	What happens	Type
Mass bleaching	Warm sea water makes corals lose their algae and turn white. In 2016 nearly a third of shallow-water corals died. More mass bleaching followed in 2017, 2020, 2022 and 2024.	Global (climate change)
Crown-of-thorns starfish	Outbreaks of this starfish eat living coral. It is helped by extra nutrients in the water.	Natural, made worse by people
Farm runoff	Rain washes fertiliser, soil and pesticides from sugar cane farms and cattle land down rivers to the sea. This feeds starfish larvae and cloudy water blocks light.	Local and regional
Cyclones	Strong waves break coral. Cyclone Yasi (2011) damaged large areas.	Natural
Shipping and coastal development	Ships carrying coal and other cargo bring the risk of groundings and oil spills. Ports and dredging cloud the water.	Local
Tourism	Boat anchors, divers touching coral and waste from resorts can damage reefs.	Local

Strategies and techniques to protect and manage the reef

Remember: strategies are the action plans and agreements, and techniques are the methods used.

📝 Strategies (plans)

Marine Park and GBRMPA (1975): one authority manages the whole area and controls what people can do in it.
Zoning plan (2004): the Marine Park is split into zones. No-take green zones, where fishing and collecting are banned, grew from about 4.5% to about 33% of the park.
Reef 2050 Plan (2015): a long-term plan from the Australian and Queensland governments, with targets for water quality, starfish control and protecting species.

🔧 Techniques (methods)

Water quality programmes: paying and advising farmers to cut fertiliser, keep soil on the land and plant ground cover.
Starfish culling: divers inject starfish with a substance that kills them. More than a million have been removed since 2012.
Restoration research: scientists test coral gardening and breeding corals that cope better with heat.
Visitor rules: tourism operators need permits, use mooring buoys and teach visitors how to avoid damage.

What does sustainable mean here?

Sustainable management of the reef means using it for tourism and fishing today in a way that does not damage it for people in the future. Zoning is sustainable because it still allows tourism and some fishing, while keeping the most valuable areas safe.

How far has it worked?

Evaluation

Strengths: the reef is often described as one of the best-managed in the world. Green zones let fish grow bigger and more numerous, which helps nearby areas too. Many farmers have joined water quality schemes. The starfish programme has protected more than 300 reefs.

Weaknesses: local plans cannot stop sea warming. Mass bleaching has continued even with the reef well protected. Water quality targets have been hard to meet because so much land drains to the reef. Starfish culling is expensive and never finished. Some people argue that new ports and coal exports still put the reef at risk.

Who benefits: tourism businesses, fishers, local communities and the whole world. The costs fall on farmers and taxpayers.

Overall: local threats are being managed well, but the biggest threat, climate change, needs global action on greenhouse gases.

Common mistakes

Writing only general coral reef points with no named detail. Always add the name (GBRMPA, Reef 2050 Plan, crown-of-thorns starfish, Queensland), a figure and a place. Another mistake is listing strategies without saying whether they worked.

Exam-style question

Fig. 1.1 is a photograph of a tourist boat moored at a reef off Cairns, with snorkellers over bleached white coral.

(a) Identify the country where the Great Barrier Reef is found. [1]

(b) Give two reasons why the Great Barrier Reef is important. [2]

(d) Evaluate the strategies and techniques used to protect and manage the Great Barrier Reef. [6]

Model answer

(a) Australia (1)

(b) It has very high biodiversity, with about 1,600 species of fish (1). It supports tourism and about 64,000 jobs (1).

(c) Warm sea water stresses the corals (1) so they lose their algae and turn white (1). If the heat lasts, the coral dies, as happened to nearly a third of shallow-water corals in 2016 (1).

(d) Level 3 answer: The zoning plan of 2004 raised no-take green zones from about 4.5% to about 33% of the Marine Park, which lets fish stocks recover (1). The Reef 2050 Plan sets targets for water quality, and farmers are helped to cut fertiliser runoff (1). Crown-of-thorns starfish are culled by divers, with over a million removed since 2012 (1). These techniques protect reefs from local threats and still allow sustainable tourism (1). However, they cannot stop the sea warming, and mass bleaching still happened in 2020, 2022 and 2024 (1). So the strategies are effective locally but not enough on their own, because global action on climate change is also needed (1).

Exam tip

For a 6-mark evaluation, give at least three named strategies or techniques, say what each achieved, and finish with a clear judgement about how well they work.

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