What occurs in an estuary?

An estuary is a dynamic and productive ecosystem where freshwater from rivers and streams meets and mixes with saltwater from the ocean. This unique environment results in brackish water, which has a salinity level that is intermediate between freshwater and seawater. The mixing of these two types of water creates a habitat that supports a diverse range of plant and animal species, making estuaries crucial for biodiversity and providing various ecological functions such as serving as nurseries for fish.

In estuaries, the salinity levels can vary due to factors like tides, rainfall, and freshwater inflow, creating a highly variable environment that is conducive to different species adapted to these conditions. This characteristic of mixing and creating brackish water is what distinguishes estuaries from purely freshwater or saltwater habitats, thus highlighting the ecological importance of estuaries in terms of productivity and habitat diversity.