Skip to page content

FSC logo
Life in Freshwater

Streams and Rivers - Moving water or Lotic System

Whilst there is a degree of uniformity within the ponds and lakes, streams and rivers are more difficult to simplify. They are an essential part of the water or hydrological cycle in that they carry the water precipitated inland and on upland regions down a slope to the sea. The movement of water introduces a factor that can substantially affect the communities of organisms able to colonise and live there. However, along their length it will be possible to find many places where the flow ceases to an extent that the animal and plant life will be more pond like. Hence you will need to refer to that part of this site.

Upland Stream
Early summer view of an upland stream. The dark coloration of the water is due to the surrounding peaty ground.

One characteristic of all rivers is that they are extremely variable along their length and even within a short section there may be substantial variation creating numerous micro-habitats. The nature of any river will be determined by the catchment area. For example, without sufficient rainfall the river could well dry out. Rivers seem very dynamic, always changing not just along their length from source to estuary but even a small section can change its environment, i.e. through erosion. New areas of land are cut into and changed whilst leaving a sweeping meander to form an ox-bow lake.

The early stages of a river are often natural and left alone or just for recreation and amenities. Once into lowland areas and as it enters the sea the river may be canalised, i.e. the bank is determined and controlled by human activity.

Controlled river
A sluggish river maintained by human activity

Industrialised river
This is the lower reaches of a river. All banks are controlled as well as silt and sand being prevented from collecting at the exit.



Looking for a next step?
The FSC offers a range of publications, courses for schools and colleges and courses for adults, families and professionals that relate to the freshwater environment. Why not find out more about the FSC?

Do you have any questions?

Site Statistics by Opentracker