Question

A key feature of estuaries is:

a. low light conditions and high productivity

b. salt water and fresh water

c. frequent algal bloom

d. little or no vegetation

Short answer

The Correct answer is option (b).

An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean.

Step-by-step solution

Introduction

An estuary is a coastal water body that is partially contained and mixes freshwater from rivers and streams with saltwater from the ocean. Estuaries, as well as the area around them, are places where land meets sea.

Reasons for the incorrect answer

• Estuaries have adequate sunshine and great productivity from creatures that have already adapted to this environment.
• Because the water is always moving, extra nutrients, if any, are swept away by the running water, and algal bloom is not a problem in this location.
• Many of the young offspring of crustaceans, mollusks, and fish begin their lives in estuaries, which also serve as vital breeding habitats for other creatures.

Reason for the correct option

In estuaries, salinity is a significant component that determines the organisms and adaptations of those species. Estuaries have a wide range of salinity, which is determined by the rate of flow of their freshwater sources, which can be affected by seasonal rainfall. High tides carry saltwater into the estuary once or twice a day. Low tides that occur at the same time reverse the saltwater stream.