Which area is the sheltered, brackish transition zone where a river meets the sea?

• A. Foreshore
• B. Fjord Estuary
• C. Estuary
• D. Fringing Reef

Answer: (C)

An estuary is the sheltered coastal area where a river meets the sea, creating a mixing zone where freshwater and seawater combine. The salinity is brackish, meaning it lies between freshwater and seawater and changes with tides and river flow. This environment is typically protected from strong wave action, supporting high productivity thanks to the nutrients carried by the river. The foreshore is simply the shore exposed to tides and waves, the fringing reef is a coral reef along the coast, and a fjord estuary is a specific type of estuary formed in a glacial valley. Because it describes the general sheltered, brackish transition zone at a river mouth, the correct term is estuary.