Estuaries are where rivers flow and empty into oceans. They are a limited resource and are being depleted by human activity. Estuaries are used for fishing, tourism, transportation, and trade. Without this valuable resource, the U.S. economy will be damaged. This will cause many Americans to go into poverty. Without estuaries, thousands of jobs will be lost, which causes unemployment and the need for more jobs. There are several biotic and abiotic features in estuaries. On top of that, there are many examples of symbiosis there. Plants and animals have to make adaptations to survive.