low salt concentration
Freshwater biomes are defined by their low salt concentration, usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration, such as the ocean. There are different types of freshwater biomes: ponds and lakes Figure below , streams and rivers, and wetlands. Ponds and lakes range in size from just a few square meters to thousands of square kilometers. Streams and rivers are bodies of flowing water moving in one direction. They can be found everywhere. They get their starts at headwaters , which may be springs, melting snow, or even lakes, and then travel all the way to their mouths , emptying into another water channel or the ocean. Wetlands are areas of standing water that support aquatic plants. Wetlands include marshes, swamps, and bogs.