Coastal management strategies are designed to reduce erosion and flood risk, but they often have significant environmental impacts. This is a key area of evaluation in IB Geography, particularly within Option B: Oceans and Coastal Margins. While management may protect people and property, it can also disrupt natural coastal systems and ecosystems.

One major environmental impact of coastal management is the disruption of sediment movement. Hard engineering structures such as groynes, sea walls, and breakwaters interfere with longshore drift. When sediment is trapped in one area, beaches further along the coast may be starved of material. This can increase erosion downstream, leading to habitat loss and narrowing beaches. In IB Geography, this is often described as transferring environmental risk rather than reducing it.

Coastal defences can also affect coastal ecosystems. Sea walls and embankments replace natural shorelines with artificial surfaces, reducing habitats for plants and animals. Intertidal zones, which are rich in biodiversity, may be squeezed between rising sea levels and fixed defences in a process known as coastal squeeze. This leads to loss of salt marshes and mudflats that provide important ecosystem services.

Managed retreat has different environmental impacts. Allowing low-lying land to flood can create new wetlands and salt marshes. These habitats support biodiversity, store carbon, and act as natural buffers against waves and storm surges. From an environmental perspective, managed retreat is often seen as more sustainable, although it may conflict with social and economic priorities.

Beach nourishment is generally considered more environmentally friendly than hard engineering, but it still has impacts. Dredging sand from offshore areas can damage marine ecosystems and disturb seabed habitats. Imported sediment may differ in grain size or composition, affecting beach organisms and nesting sites for birds and turtles.

Coastal management can also influence water quality. Construction activity may increase turbidity, while altered currents can change patterns of pollution dispersion. In some cases, defences reduce natural flushing of coastal waters, increasing the risk of pollution build-up.

In IB Geography, it is important to recognise that environmental impacts vary over time. Some impacts are immediate, such as habitat loss during construction, while others are long-term, such as changes to erosion patterns or ecosystem decline. Management strategies may require ongoing maintenance, further increasing environmental pressure.

Overall, coastal management can protect coastlines but often alters natural processes and ecosystems. Sustainable coastal management aims to minimise environmental damage by working with natural systems rather than against them.

RevisionDojo helps IB Geography students evaluate the environmental impacts of coastal management clearly, linking physical processes, ecosystems, and sustainability into strong, exam-ready responses.