Given what we know, we can confirm that estuaries are characterized by the presence of fresh water and salt water.
As stated in the question, estuaries are bodies of water. Said bodies of water tend to be costal and are mainly characterized by the presence of salt water from the ocean mixing with fresh water from rivers.
Therefore, we can confirm that estuaries are characterized by the presence of fresh water and salt water.
To learn more about rivers visit:
https://brainly.com/question/8807634?referrer=searchResults