Which process describes the gradual change in species composition in coastal areas over time?

The process that describes the gradual change in species composition in coastal areas over time is ecological succession. This is a natural, ongoing process where one community of organisms gradually replaces another over time, often following a disturbance or the creation of new habitats. In coastal environments, this could involve changes initiated by factors such as sea level rise, sediment deposition, or human activity. During succession, organisms like plants and animals establish themselves and modify the environment, enabling different species to thrive in a more developed ecosystem, ultimately leading to increased biodiversity.

Other processes mentioned, such as erosion and weathering, refer to the physical and chemical breakdown of rocks and soils and are not directly related to the changes in species composition. Coastal migration refers to the movement of landforms or ecosystems along the coast but does not focus on the transformation of species over time. Thus, ecological succession is the most accurate term for the gradual change in species composition in coastal areas.