[Campbell Biology P.1229] Which of the following statements about estuaries is FALSE? | Practice Question
Which of the following statements about estuaries is FALSE?
A: Estuaries are transition areas where fresh river water mixes uniformly with saltwater from the sea.
B: Salinity in estuaries varies both spatially and with the rise and fall of tides.
C: Estuaries are among the most productive biomes due to nutrient input from rivers.
D: Saltmarsh grasses, algae, and phytoplankton are the major producers in estuaries.
Explanation
The 'Physical Environment' section under 'Estuaries' states that higher-density seawater occupies the bottom of the channel and mixes little with the lower-density river water at the surface, indicating mixing is not uniform.