Option B • Section 3
Managing Coastal Margins
Coastal risks, competing stakeholders, management choices and ecosystem-based protection.
The varying power of different stakeholders in relation to coastal-margin management
Coastal erosion and flooding
Diagnose the connected hazards, then evaluate whether to hold, advance or move the line—or allow natural change.
Coastal erosion removes and redistributes material, while coastal flooding temporarily covers normally dry land. Storms can intensify both processes: waves attack beaches and cliffs as storm surge and high tide allow seawater to overtop or breach low-lying defences. Management therefore needs to consider the whole sediment cell, the people and assets exposed, and whether a response transfers risk elsewhere.
From diagnosis to decision
1. Use the visual guide to distinguish erosion from flooding and identify the physical and human drivers of each. 2. Classify the options as hard engineering, nature-based protection, cliff-line stabilisation or managed retreat. 3. Compare cost, lifespan, effectiveness, environmental impact, beneficiaries and transferred risk. 4. Recommend a mixed strategy for a named coastline and justify when the plan should be reviewed.
Coastal stakeholders
Residents, businesses, tourists, fishers, conservationists and governments value coastlines differently.
Power comes through ownership, law, finance, expertise, political access and the ability to frame a problem. Management decisions distribute benefits and losses unevenly across space and time.
Stakeholder hearing
Assign roles, establish each stakeholder’s desired outcome, evidence and power, then negotiate a coastal plan. Record who gains, who pays and whose voice remains weak.
Ban Khun Samut Chin
A rapidly retreating coastline in the Upper Gulf of Thailand near Bangkok.
Land subsidence, reduced sediment supply, mangrove loss, aquaculture and changing wave conditions combine with sea-level rise. The case exposes difficult choices between protecting communities, restoring ecosystems and accepting retreat.
Management decision
Rank the physical and human causes, compare structural and ecosystem-based responses, then recommend a plan with a clear stakeholder and timescale justification.
Maritime sovereign rights
Territorial seas and exclusive economic zones shape access, management and conflict.
UNCLOS balances coastal-state rights with navigation and shared responsibilities. EEZs extend resource rights up to 200 nautical miles, but overlapping claims and mobile resources complicate management.
Mangroves
Mangrove ecosystems reduce wave energy, trap sediment, store carbon and support fisheries.
Natural-capital assessment
Classify mangrove benefits as regulating, provisioning, supporting and cultural services. Compare restoration with a seawall and identify where a hybrid solution is strongest.
Coral reefs: value, threats and management
Highly productive ecosystems support biodiversity, coastal protection, fisheries, tourism and cultural value.
Reef-management enquiry
Build a value–beneficiary–threat table for one reef. Evaluate marine protected areas, tourism controls, fisheries regulation, restoration and global emissions reduction at different scales.
Concluding challenge — Coastal Escape Room
Use evidence from the mangrove and coral-reef sections to solve the challenges. Keep a record of the ecosystem services, threats and management strategies used in each answer, then identify which coastal-management approach offers the strongest long-term resilience.
Launch the activity below. It opens full-screen because Canva does not permit this published interactive to run inside another website.
Coastal management judgement
Effective management integrates physical processes, ecosystems, stakeholders, finance and uncertainty.
Exam practice
Evaluate the view that ecosystem-based management is more effective than hard engineering at coastal margins. Use two contrasting places, stakeholder perspectives and a justified conclusion.