Chapter 3.3, Problem 5MI

Summary Introduction

To analyze:

The effect of speed of water flow on life in river by completing the given chart.

Introduction:

Major freshwater ecosystems are ponds, lakes, streams, rivers and wetlands. Plants and animals living n freshwater are adapted to the low salt content and are unable to survive in areas of high salt content. Only 2.5% of the water on Earth is freshwater. The water in rivers and streams flows in one direction.

Explanation of Solution

Rivers and streams start from a source called headwater and travel to the mouth, where the flowing water empties into a large water body. The slope of the landscape determines the direction and speed of water flow. When the slope is steep, water flows quickly causing a lot of sediment to be picked up and carried by water. Sediment is the material that is deposited by water, wind or glaciers. As the slope levels the speed of water flow decreases and sediments are deposited in the form of sand, silt and mud.

The currents and turbulence of fast-moving rivers and streams prevent much accumulation of organic matter and sediment. Due to this, very few species live in rapid water. Only those species that can withstand the water current are able to survive. The turbulent churning action of water does not allow roots to grow.

In slow moving water, many species of fish, eel, crabs, worms, insect larvae are present. Animals like newt, frogs and tadpoles live-in slow-moving water. Plants that can root themselves into the streambed are common in areas where water is slowed by rocks and sand bars.