Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment (hierarchy name)
4. Settlements and Landscapes (hierarchy name)
5. landscapes (environments)
6. natural landscapes
7. bodies of water (natural)
8. marine bodies of water
9. [marine bodies of water by biome]

Anotations

Scope note:

Category of marine body of water comprising areas where freshwater streams or rivers merge with the ocean. This mixing of waters with such different salt concentrations creates a very interesting and unique ecosystem. An estuary is usually a funnel-shaped stream mouth or embayment where fresh water mixes with sea water under tidal influences.