Coast

Coast describes the boundary where land meets a sea or ocean. Coastlines can be rocky cliffs, sandy beaches, salt marshes, mangrove forests, or icy shores. Waves, tides, river sediment, and wind constantly reshape these edges, creating dunes, barrier islands, and estuaries.

Coastal ecosystems are rich in biodiversity. Tide pools shelter starfish and anemones, salt marsh grasses filter runoff, and mangroves cradle fish nurseries while buffering storms. coral reefs and seagrass beds offshore also form part of many coastlines, supporting fisheries and tourism.

People have long settled along coasts for access to trade, food, and travel. Major cities—New York, Shanghai, Lagos, Sydney—grew around harbors. Ports handle global shipping, while beaches attract visitors who support local economies. Coastal farms and aquaculture operations produce seaweed, oysters, and shrimp.

Coasts also face hazards. storm surges, hurricanes, and tsunamis can flood low-lying areas, while erosion removes protective dunes. sea-level rise from climate change threatens infrastructure, drinking water supplies, and wildlife habitats. pollution from land—plastic, oil, fertilizers—often washes into coastal waters, harming reefs and fisheries.

Communities manage coasts using tools such as dune restoration, seawalls, wetland conservation, and smart zoning. Scientists monitor shoreline change with drones and satellites, and planners use hazard maps to guide development. Individuals can help by respecting dunes, disposing of trash properly, and supporting policies that reduce greenhouse-gas emissions.