Definition: An estuary is a wetland where upland freshwater and ocean saltwater mix. Estuaries are among the most biologically productive and diverse habitats. They function as critical habitat for migrating waterfowl and serve as nurseries for many fish species. Estuaries are sensitive to disturbance from pollution, siltation, erosion, and invasive species. Estuaries are becoming rare due to a variety of threats including drainage and infilling.
Also Known As: slough
