Why Western Coastal Plains Have Many Lagoons

Lagoons abound on western coasts due to interacting geological and oceanographic processes:

1. Barrier Island/Spit Formation: Wave-driven sediment builds sandbars parallel to shore, enclosing water bodies.
2. River Deltas: Sediment deposition creates distributary channels, islands, and interdistributary lagoons (e.g., Mississippi, Niger, Ganges).
3. Estuaries: Drowned river valleys mix fresh/salt water, forming lagoonal environments.
4. Tidal Range & Sediment Supply: Low-to-moderate tides with ample sediment favor barrier-lagoon systems.
5. Sea-Level History: Holocene transgression flooded coastal valleys, creating lagoons behind barriers.
6. Climate & Vegetation: Mangroves/marsh grasses stabilize lagoon margins.

These lagoons are critical nurseries for fisheries, bird habitat, and carbon sinks.