Question

medal + fan :]
please help

Answer 1

@jherrera57 can you help me again, sorry?

Answer 2

OK. Estuaries are anywhere that freshwater and saltwater mix and many of them are in bays where rivers empty. These are also historically the places where most people like to live, from the very earliest times to the present. Most harbors are estuaries and many people live around them, large cities grow up around them because harbors are important for transportation of people and products. So, estuaries are very polluted from wastes from ships and runoff from the land from the activities of people, like gas and oil from cars and fertilizer runoff from lawns and golf courses.
Estuaries are important habitat because many of them have seagrasses and other photosynthesizers that make them very productive, and because they are nursery grounds for many types of marine life, including commercial species that are important to people as food.

Answer 3

Ohh that makes sense. Ships and other human creations dump their waste in the water or near it and the water becomes polluted... thanks! :]

Answer 4

Estuaries also require some kind of "entrainment" to be estuaries. That means the salt and freshwater are held together to some extent and mix. Everything doesn't just get washed away or diluted out right away. There has to be some kind of restricted flow like a bay instead of the open ocean or behind barrier islands instead of the open ocean beach.