Changing Coastal Environments » Case Study - Coral Reef Example

What you'll learn this session

Study time: 30 minutes

The structure and importance of coral reef ecosystems
Threats facing coral reefs including climate change and human activities
Case study of the Great Barrier Reef in Australia
Conservation and management strategies for coral reefs
How to evaluate the effectiveness of coral reef protection measures

Coral Reefs: Coastal Treasures Under Threat

Coral reefs are among the most diverse and valuable ecosystems on Earth. Despite covering less than 1% of the ocean floor, they support about 25% of all marine species! These coastal wonders are not only beautiful but also economically and ecologically vital.

Key Definitions:

Coral reef: A diverse underwater ecosystem built by colonies of tiny animals called coral polyps that secrete calcium carbonate to form a hard skeleton.
Coral bleaching: The process where corals expel their symbiotic algae (zooxanthellae) due to stress, causing them to turn white and potentially die.
Ecosystem services: The benefits people obtain from ecosystems, including food, coastal protection and tourism opportunities.

🌀 Coral Reef Structure

Coral reefs are built by tiny animals called polyps that form colonies. These polyps extract calcium from seawater to create hard limestone skeletons. Over thousands of years, these skeletons build up to form the massive structures we know as coral reefs. Corals have a symbiotic relationship with algae called zooxanthellae, which provide food through photosynthesis and give corals their vibrant colours.

🌊 Types of Coral Reefs

There are three main types of coral reefs:
• Fringing reefs: Grow near coastlines with little or no separation from land
• Barrier reefs: Separated from land by a lagoon
• Atolls: Circular reefs surrounding a lagoon with no central island

The Importance of Coral Reefs

Coral reefs provide numerous benefits to both nature and humans:

🌏 Environmental Value

• Habitat for 25% of marine species
• Nurseries for fish populations
• Carbon sinks that absorb CO₂
• Protect coastlines from erosion and storm damage

💰 Economic Value

• Support fishing industries worth billions
• Tourism revenue (diving, snorkelling)
• Potential for medical discoveries
• Coastal protection saves money on sea defences

🏠 Social Value

• Cultural significance for coastal communities
• Food security for millions of people
• Employment opportunities
• Educational and research value

Threats to Coral Reefs

Despite their importance, coral reefs face numerous threats that have led to significant decline worldwide:

🌡 Climate Change Impacts

Ocean warming: Rising sea temperatures cause coral bleaching. When water gets too warm, corals expel their colourful algae partners, turning white and potentially dying if stress continues.

Ocean acidification: As oceans absorb more CO₂, the water becomes more acidic, making it harder for corals to build their calcium carbonate skeletons.

Sea level rise: Rapid sea level changes can leave some corals too deep to receive adequate sunlight.

👤 Human Activities

Overfishing: Removing key species disrupts the reef ecosystem balance.

Pollution: Agricultural runoff, sewage and plastic waste damage coral health.

Destructive fishing: Methods like dynamite fishing and cyanide fishing directly destroy reef structures.

Coastal development: Construction increases sedimentation, blocking sunlight corals need.

Did You Know?

The world has already lost about 50% of its coral reefs and without significant action, scientists predict that 90% of the world's coral reefs could be gone by 2050!

Case Study: The Great Barrier Reef, Australia

The Great Barrier Reef (GBR) is the world's largest coral reef system and a perfect example of both the threats facing reefs and efforts to protect them.

Case Study Focus: Great Barrier Reef

Location: Off the coast of Queensland, Australia
Size: 2,300 km long, covering approximately 344,400 km²
Biodiversity: Home to over 1,500 fish species, 411 types of hard coral, 134 species of sharks and rays, 6 of the world's 7 marine turtle species
Economic value: Contributes about AU$6.4 billion annually to the Australian economy through tourism, fishing and recreation

Threats to the Great Barrier Reef

The GBR has experienced several major bleaching events in recent years:

2016-2017: Back-to-back bleaching events affected over two-thirds of the reef
2020: Another major bleaching event occurred, the third in five years
Agricultural runoff: Fertilisers and pesticides from farming wash into the reef
Crown-of-thorns starfish: Outbreaks of these coral-eating predators, often linked to nutrient pollution
Shipping: Risk of groundings, oil spills and increased sediment from port dredging

Management and Conservation Efforts

Australia has implemented various strategies to protect the Great Barrier Reef:

📝 Policy and Regulation

• Great Barrier Reef Marine Park Act (1975): Established the Marine Park Authority to manage and protect the reef

• Zoning Plan (2004): Created a network of no-take zones covering 33% of the Marine Park

• Reef 2050 Plan: Long-term sustainability plan with targets for improving water quality and reducing greenhouse gas emissions

🔬 Scientific Initiatives

• Reef restoration: Coral nurseries and transplantation projects to help damaged areas recover

• Crown-of-thorns control: Programs to manually remove these coral-eating starfish

• Reef monitoring: Regular surveys to track reef health and identify areas needing intervention

• Heat-resistant corals: Research into breeding corals that can better withstand higher temperatures

Effectiveness of Management Strategies

The management of the Great Barrier Reef shows both successes and ongoing challenges:

✅ Successes

• Marine protected areas have shown higher fish populations and coral cover
• Water quality improvements in some areas due to better agricultural practices
• Increased public awareness and tourism industry involvement in conservation
• UNESCO World Heritage status has helped secure international support

❌ Limitations

• Climate change remains the biggest threat and requires global action
• Economic interests sometimes conflict with conservation needs
• Recovery from bleaching is slow and repeated events give little recovery time
• Enforcement challenges in such a vast marine area

Global Coral Reef Conservation

Beyond the Great Barrier Reef, there are worldwide efforts to protect coral ecosystems:

International Coral Reef Initiative (ICRI): A global partnership between governments, NGOs and international organizations
Coral Triangle Initiative: Collaboration between six countries in Southeast Asia and the Pacific to protect the world's epicentre of marine biodiversity
50 Reefs Initiative: Scientific approach to identify and protect coral reefs most likely to survive climate change
Coral Reef Alliance: Works with local communities to implement sustainable practices

Exam Tip!

For your iGCSE Geography exam, remember to include specific facts and figures from the Great Barrier Reef case study. Being able to name specific management strategies and evaluate their effectiveness will help you score higher marks. Also, be prepared to discuss the conflicts between economic development and environmental protection.

Key Takeaways

Coral reefs are incredibly valuable ecosystems facing severe threats from climate change and human activities. The Great Barrier Reef case study demonstrates both the challenges of coral reef conservation and the range of management strategies being employed. While local actions can help reduce some pressures, addressing climate change is essential for the long-term survival of coral reefs worldwide.

As future decision-makers, understanding these coastal environments and the complex issues surrounding their conservation is crucial. The fate of coral reefs will depend on our ability to balance human needs with environmental protection and to take decisive action on climate change.

🧠 Test Your Knowledge!