Freshwater: Streams and Rivers
Streams and rivers form dynamic lotic systems that change dramatically from their source to their mouth. These flowing water systems start as shallow, cold, fast-moving streams with high dissolved oxygen and low nutrients, limiting their productivity.
As you move downstream to the transition zone, the stream widens, slows down, and warms up. This creates conditions for more sun exposure and increased productivity, though dissolved oxygen begins to decrease.
The final floodplain zone features the warmest temperatures and slowest water movement. Here you'll find the highest net primary productivity (NPP) but also high turbidity (muddy water) and lower dissolved oxygen levels.
Quick Fact: All streams and rivers exist within watersheds (drainage basins) that collect runoff, sediments, and dissolved substances from the surrounding land – similar to how rain gutters collect water from a roof!
