Question

What is the defining characteristic of an estuary?

A) It is a freshwater lake connected to the ocean.
B) It is a deep trench in the ocean floor.
C) It is an inlet of the ocean that extends into a river valley.
D) It is a high mountain range near the coast.

Answer 1

Estuaries are biomes where fresh water from rivers meets the ocean, resulting in a mix of fresh and salt water. They are important habitats for many marine organisms and provide protected areas for the young offspring of crustaceans, mollusks, and fish. The salinity of estuaries varies based on the flow of freshwater sources and is influenced by tides.

Step-by-step explanation:

Estuaries are biomes that occur where a source of fresh water, such as a river, meets the ocean. Therefore, both fresh water and salt water are found in the same vicinity; mixing results in a diluted (brackish) saltwater. Estuaries form protected areas where many of the young offspring of crustaceans, mollusks, and fish begin their lives. Salinity is a very important factor that influences the organisms and the adaptations of the organisms found in estuaries. The salinity of estuaries varies and is based on the rate of flow of its freshwater sources. Once or twice a day, high tides bring salt water into the estuary. Low tides occurring at the same frequency reverse the current of salt water.