The letters following each Review Question refer to the corresponding Learning Objective from the Chapter Opener. Discuss the different types of coastal wetlands. How does a reef surrounding an oceanic island change with time? (F)

Coastal wetlands are primarily classified into salt marshes, mangrove swamps, tidal flats or mudflats, and estuaries. Salt marshes are found in temperate regions and are influenced by the tide, while mangrove swamps are tropical or subtropical wetlands characterized by salt-tolerant mangroves. Tidal flats refer to the wetlands formed by deposited mud from rivers and tides, and estuaries are where rivers meet the sea, characterized by brackish water. A reef surrounding an oceanic island, such as a coral reef, undergoes changes over time due to ecological processes and geological transformations. Initially, as corals grow along the coast, a fringing reef forms around the island. Subsequently, the island may sink, or the sea level may rise, leading to the formation of a barrier reef separated from the shore by a lagoon. Finally, when the island sinks beneath the surface, a ring of coral with a central lagoon forms an atoll. This progression from fringing reef to barrier reef to atoll is called Darwin's theory of coral reef formation.