Rivers

Freshwater habitats

River habitats encompass all natural and near-natural running waters in the UK, i.e. with features and processes that resemble those in 'natural' systems. Numerous factors influence their ecological characteristics. These include:

  • catchment features (geology, soil, vegetation, etc) 
  • topography
  • gradient and flow rate
  • altitude
  • channel profile
  • climate
  • land use and other human activities

    Freshwater habitats

 

There are many different types of river, for example:

  • slow-flowing meandering rivers in the lowlands (see right)
  • fast-flowing headwater streams associated with the uplands (see right)
  • chalk and limestone rivers
  • rivers with strongly acidic, nutrient-poor waters

 

Rivers change greatly in character from their source, through their headwaters, and downstream to the sea or a lake. Specialized habitat features associated with rivers include rapids and riffles, in-stream rocky substrates, exposed shingle banks, scour pools, and gravel beds (see right).

Freshwater habitats

 

Rivers are home to many species of wildlife . These includes plants, such as water-crowfoot, water-starwort, water-cress and water-milfoil. Many species of fish use river habitats, including Atlantic salmon, brook lamprey, brown trout, bullhead, eel, perch and pike. Other well-known species include otter, water vole, and birds like dipper and kingfisher. A great number of invertebrate species are found in riverine habitats, including aquatic beetles, caddisflies, damselflies, dragonflies, mayflies and stoneflies.