Key Idea: Topic 8.3 is about how we manage the coast — and why nearly every choice causes a fight. It pulls together two ideas: 8.3.1 — flooding, erosion & conflict: the hard engineering (sea walls, groynes, rock armour), soft engineering (beach nourishment, salt marsh) and managed retreat used against erosion and flooding — and how each one creates winners and losers, so management is really about stakeholder conflict. 8.3.2 — ocean & coastal pollution: the types of marine pollution (plastics, nutrients/eutrophication, oil and chemicals, aquaculture waste) and ocean acidification from dissolved CO2 — most of it land-based and hard to manage because the ocean is a shared, open resource. This is Option B content, examined on Paper 1. SL answers 2 chosen options, HL answers 3 (same questions). Each option gives a structured question plus a [10] extended-answer essay (Examine / Evaluate / Discuss).
🌊 8.3.1 — Managing coasts: strategies & conflict
Coasts face erosion (the sea wearing the land away) and coastal flooding (the sea covering low land, often in a storm surge). Managing them means picking a strategy — and every strategy helps one group and costs another. The skill examiners test is reading a coastal management-zone map (Estimate a distance off the scale, Identify the most/least restricted zone), then weighing the stakeholders who clash over how the coast is defended.
[Diagram: geo-choropleth]
Tip: For the map marks: Estimate a distance against the scale bar (a sensible range is accepted) and quote the units; Identify the zone straight off the key (lightest = most open, darkest = no-take). For the conflict, never just say 'there is conflict' — name who wants what and why it cannot all happen. Defending one beach with a sea wall starves the next one, so the down-drift community objects.
🛢️ 8.3.2 — Ocean & coastal pollution
Around 80% of marine pollution starts on land and reaches the coast via rivers and run-off. The main types are plastics (the biggest by volume, trapped on coasts by waves and currents), nutrients (sewage + fertiliser → eutrophication and dead zones), oil and chemicals, and aquaculture waste. Dissolved CO2 drives ocean acidification, weakening coral reefs — but not uniformly.
The ocean is a shared, open resource — pollution dumped in one place spreads across borders, so no single country is responsible. Plastic is durable, breaks into microplastics and collects in gyres (the Great Pacific Garbage Patch), making it far harder to clean than a contained oil spill. That is why management works best when it tackles land-based sources and is coordinated across stakeholders — and why diffuse, durable plastic resists control most.
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Exam Tips
- Option B sits on PAPER 1: each option = a structured question + a [10] Examine/Evaluate/Discuss essay (SL does 2 options, HL does 3).
- Hard = resist the sea; soft = work with nature; managed retreat = give ground. Every strategy has winners AND losers — name the stakeholders that clash.
- Defending one beach starves the next (down-drift erosion); conflict resists resolution because money is limited and stakeholder power is unequal.
- On a coastal map: ESTIMATE a distance off the SCALE BAR (a range is accepted, quote units), and IDENTIFY zones straight off the key.
- About 80% of marine pollution is land-based; plastic builds up on coasts (closest source + waves/currents/onshore winds) and resists control because the ocean is a shared, open resource.
- Acidification: CO2 → carbonic acid → lower pH → less carbonate for reefs — but impacts are NOT uniform. On the [10] always weigh both sides, use a named example, and finish with a justified judgement.