Which water body is brackish and tidal?
An estuary is a partly enclosed coastal water body where river water mixes with seawater and tidal action influences water level and circulation. Mixing produces brackish water, whose salinity lies between fresh and fully marine conditions and often varies over each tide, season, and position along the estuary. Density differences can create a salt wedge or partial stratification, while tidal currents transport sediments, oxygen, nutrients, plankton, and organisms. Estuaries support salt marshes, mangroves, mudflats, seagrass beds, nursery grounds, and productive detrital food webs. A river is
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 2-3
