What are the main types of coastal landforms formed by marine processes such as erosion, deposition, and sediment transport, and how do features such as beaches, spits, barrier islands, tidal flats, and estuaries develop along coastlines, providing valuable habitats, recreational opportunities, and coastal protection services for human societies and ecosystems?

Coastal landforms are shaped by marine processes such as erosion, deposition, and sediment transport, creating a diverse array of features along coastlines. Beaches form through the deposition of sand and gravel by wave action, providing recreational opportunities and habitat for coastal species. Spits are elongated coastal landforms that extend from the shoreline into open water, formed by the longshore drift of sediment. Barrier islands are low-lying sandy islands parallel to the coastline, separated from the mainland by lagoons or tidal channels. Tidal flats are extensive areas of mudflats or sandflats exposed at low tide, supporting unique ecosystems adapted to fluctuating water levels. Estuaries are semi-enclosed coastal water bodies where freshwater rivers meet and mix with seawater, creating dynamic ecosystems rich in biodiversity. These coastal landforms provide valuable habitats, recreational opportunities, and coastal protection services for human societies and ecosystems, buffering coastlines from erosion, storm surges, and sea level rise.