Seffen and Moravichik introduce estuaries by explaining how fresh water from rivers flows to the sea and mixes with salt water. Estuaries are nature's water mixers because in coastal regions, fresh water from rivers meets salt water from the ocean and is mixed in many different ways. The diverse mix of salt and fresh water creates different habitats with a complex ecosystem. Estuaries are important for the environment as well as the economy. Estuaries have very different temperatures and precipitation averages due to the different regions where they are located. Keeping estuaries healthy is an important task worldwide. Estuarine biomes are full of surprises (Seffen & Moravichik, 2008). According to the EPA, Environmental Protection Agency, estuaries are very important to the economy and environment of each continent where they are found. In the United States alone, 75% of commercial fishing comes from estuarine habitat. This adds $4.3 billion per year from estuaries to our economy. Healthy habitat in estuaries allows for the continued survival of many birds, animals, reptiles and diverse aquatic life. Estuaries also provide recreation and tourism is another driver of the economy (EPA, 2012). Estuaries offer many advantages. The natural barrier they provide can help prevent flooding, they help filter the water in our oceans, the fish found there are a major source of protein and help maintain the fish population in the ocean . Estuaries also provide employment and recreation. As the most productive ecosystems in the world, they are extremely important to humanity. It's no surprise that the biggest threat to estuaries is humanity. They were filled, dredged or over...... middle of paper ......remappingfoundation.org/natmap/marine/estuary_animals.htmlEPA. (2012). Basic information about estuaries. Retrieved March 14, 2014 from http://water.epa.gov/type/oceb/nep/about.cfmNelson, R., Stenstorm, J., Audel, H., Coleman, J., Walker, M., Serengeti , S. and Tucker, D. (2003). Estuarine biome. Retrieved March 12, 2014 from http://thewildclassroom.com/biomes/estuaries.htmlSeffen, P. and Moravchik, B. (March 25, 2008). Estuaries. Retrieved March 18, 2014 from http://oceanservice.noaa.gov/education/kits/estuaries/htmlSeffen, P. and Moravchik, B. (March 25, 2008). Estuaries Middle School Curriculum 101. Retrieved March 11, 2014, from http://estuaries.noaa.gov/Teachers/estuaries.aspxWassilieff, M. (July 13, 2012). 3. Estuary Plants – Estuaries – Te Ara Encyclopedia of New Zealand. Accessed March 12, 2014 from http://www.teara.govt.nz/en/estuaries/page-3