Bodies of Water in Coastal Plains: Bays, Estuaries, Lagoons & More

Coastal plains host diverse water bodies shaped by geology and hydrology:

• Bays – Broad coastal indentations (larger than coves, smaller than gulfs); often drowned river valleys.
• Coves – Small, sheltered inlets; formed by cliff erosion or sediment deposition.
• Estuaries – River mouths where fresh and saltwater mix; critical nurseries for marine life.
• Fjords – Deep, steep-walled glacial valleys flooded by the sea (Scandinavia, Alaska, Chile, NZ).
• Gulfs – Large coastal inlets; often drowned coastal plains/river valleys.
• Lagoons – Shallow, brackish waters separated from the ocean by barrier islands/reefs (tropical/subtropical).
• Sounds – Wide navigable channels between landmasses; formed by erosion or deposition.

Each type supports distinct ecosystems and human uses—from ports to preserves.