Energy laden nutrients, originally derived from riparian forests, are eaten and released and eaten again as they spiral downstream. These nutrients flow from headwaters to mid-reach streams where other aquatic communities await. Nutrients flowing from mid-reach to lower river reaches are harvested by a different community of collectors. Excess nutrients finally flow out of river mouths to enrich estuaries. Estuaries in turn release their nutrients into the world s coastal waters.
Watersheds are far more complex than just streams and rivers.
They are composed of swamps, marshes, blackwater streams and other special habitats. Watersheds include not just surface waters, but aquifers, groundwaters and the hyporheic zone. The high energy hyporheic zone forms a wet sleeve of solid material and water that surrounds the free flowing waters of streams, rivers and wetlands and is one of the most challenging frontiers of watershed ecology. Rapid assessment, routine monitoring and detailed study of rivers and entire watersheds are critical to further our understanding of not just general watershed ecology, but local streams systems in particular. We are often not able to afford time and money to conduct such detailed investigations as may be required.