What is Freshwater? Fresh water is any naturally occurring liquid or frozen water that contains minimal concentrations of total dissolved solids and dissolved salts. Freshwater includes oceans, lakes, rivers, and other non-salt mineral-rich waters. Freshwater is also known as "non-seawater." The water cycle of the Earth is a complex one, and freshwater is no exception. Many freshwater sources contribute to the water cycle. Approximately 3% of all water on the planet is freshwater. While much of this is permanently frozen as ice or restricted to underground sources, it's still a large part of the water cycle and important for life on Earth. For example, Lake Baikal is made up of only 1% freshwater, despite having more than 700 species of fish. Freshwater biomes are home to 700 species of fish, more than 1, 200 types of amphibians, and many other animals. Most of these animals are tiny and play an important role in maintaining the health of the freshwater ecosystem. Other fascinating freshwater animals include turtles, frogs, salamanders, beavers, and tadpoles. Insects such as mosquitoes also live in freshwater biomes. The Amazon River starts in the Andes Mountains and flows into the Atlantic Ocean. As it travels, the Amazon has a volume that is equal to the combined volume of the five Great Lakes of North America. The Congo River boasts of being the deepest river in the world, reaching 720 ft. Generally, the temperature of freshwater varies by location, climate, and season. In the summer, it ranges from 65 to 75 degrees Fahrenheit, while in the winter, it's about 35 to 45 degrees Fahrenheit.