Discuss the different types of coastal wetlands. Describe the different kinds of reefs and how a reef surrounding an oceanic island changes with time.

Coastal wetlands are areas where land meets the sea. They play an essential role in supporting diverse ecosystems due to their fertile soils and unique conditions. These wetlands can be classified into two main types: estuarine and marine wetlands. 1. Estuarine Wetlands: Estuarine wetlands occur where rivers meet the sea. Some examples of estuarine wetlands include salt marshes, mangroves, and transitional zones. - Salt Marshes: Found in temperate regions, they are characterized by non-woody salt-tolerant plants such as cordgrass and sea lavender. - Mangroves: Mostly found in tropical and subtropical regions, mangroves are made up of salt-tolerant tree species that can survive in brackish and saline waters. - Transitional Zones: These areas are composed of a mix of plant species found in both salt marshes and mangroves. 2. Marine Wetlands: These wetlands are influenced by tides and waves and can be found along coastlines. Examples include rocky and sandy shores, seagrass beds, and coral reefs.

Reefs are diverse underwater ecosystems formed by the accumulation of coral skeletons and algae. There are three main types of reefs: 1. Fringing Reefs: Fringing reefs grow along the coastline and are the most common type of reef. They are directly connected to the shore or separated by a shallow channel. 2. Barrier Reefs: Barrier reefs are similar to fringing reefs, but they are separated from the coastline by a deeper and wider lagoon, forming a barrier between the open ocean and the shore. 3. Atolls: Atolls are circular reef formations that encircle a central lagoon. They often form around a submerged volcanic island or seamount.

A reef surrounding an oceanic island changes with time due to geological processes, climate change, and human activities. The three main stages of reef development around an oceanic island are: 1. Island Formation: As a volcanic island emerges from the sea, corals begin to colonize the shallow areas around it, forming a fringing reef. 2. Barrier Reef Formation: Over time, the volcanic island starts to sink due to erosion and geological processes. As the island subsides, the corals continue to grow upward to maintain access to sunlight. This eventually results in the formation of a barrier reef separated from the island by a lagoon. 3. Atoll Formation: Eventually, the volcanic island completely sinks below the surface, leaving a circular ring of coral encircling a central lagoon. This final stage is called an atoll. Through these steps, we have discussed different types of coastal wetlands, defined the various kinds of reefs, and explained the changes a reef surrounding an oceanic island undergoes with time.