Managing coastal margins

The **wearing away and removal** of cliff or beach material by waves.

The sea **covering low-lying land**, often during a **storm surge**.

**Built defences** that resist the sea — sea walls, groynes, rock armour.

**Working with nature** — beach nourishment, dune planting, salt marsh.

Deliberately **letting the sea flood low land** instead of defending it, often making salt marsh.

Any **person or group** with an interest in how the coast is used or protected.

It traps/reflects sand, **starving the next beach down-drift**, so that community erodes faster and objects.

It is cheap and sustainable but means **losing homes and farmland**, so residents and farmers resist it.

Marine-park **zoning** separates fishing, diving and conservation; tourism, fishers and inland farmers (run-off) all clash over access.

Mangroves are a natural storm defence, but locals clear them for shrimp ponds and firewood, weakening the very barrier that protects them.

Defending one place harms another, money is limited, and **stakeholder power is unequal** — wealthy areas are defended first.

Hard + soft + managed-retreat strategies, two+ stakeholder conflicts, their power/perspectives, a named coast, and a justified conclusion.

Harmful waste entering the ocean - **plastics, oil, chemicals and nutrients** - mostly **land-based** and carried out by rivers and run-off.

About **80%**, reaching the sea through **rivers and run-off**.

Coasts are **closest to the source** and **waves, currents and onshore winds** trap floating plastic near the shore.

Tiny plastic fragments **under 5 mm**, formed as larger plastic breaks down; they spread through the food chain.

**Nutrient pollution** (sewage, fertiliser) that triggers **algal blooms** and low-oxygen **dead zones** that kill marine life.

**Eutrophication** under cages, **sea lice/disease**, **escaped farmed fish**, or **depleted feeder-fish** stocks.

Falling seawater **pH** as the ocean absorbs atmospheric **CO2**, forming carbonic acid and removing carbonate ions.

Lower pH means fewer **carbonate ions**, so corals build **calcium-carbonate skeletons** more slowly and existing skeletons can dissolve.

Acidification combines with **warming/bleaching** and depends on local conditions - cooler, deeper, well-flushed reefs cope better.

It is **durable**, breaks into **microplastics**, spreads into **gyres**, and crosses borders in a **shared** open-ocean resource.

The **Great Pacific Garbage Patch** (plastic in a gyre) or **Deepwater Horizon** 2010 (an oil-spill coastline disaster).

**Both sides** of the argument, a **named example**, and a **justified judgement** (e.g. why some pollution is harder to manage).