Coastal wetlands do not produce fresh water; instead, they are transitional zones between land and water that provide numerous ecological functions.

Coastal wetlands, including salt marshes and mangroves, play vital roles such as carbon sequestration, where they capture and store carbon dioxide, thus mitigating climate change. They also serve as critical habitats for fish and birds, supporting biodiversity, and are natural filters that remove pollutants from water, improving water quality. However, wetlands do not produce fresh water; they are often brackish (a mix of salt and fresh water) or saline, depending on their proximity to the ocean. Fresh water is produced naturally through the water cycle, not by wetlands.