Successful populations of wild trout are an indicator of the health of the countryside.

Wild trout need cool, unpolluted, well-oxygenated water, clean gravel in which to spawn and bankside and in-stream plants to provide cover and food.

A habitat that supports healthy trout will support many other varieties of wildlife such as invertebrates, birds and mammals.  When wild trout stop thriving, it is almost certain there are serious problems
with the environment. This is when the Wild Trout Trust can help.

Spawning
For natural reproduction, wild trout need clean, silt-free gravel with a constant flow of cool, well oxygenated and unpolluted water.  Adult fish bury their eggs in gravel 'nests' known as redds. Adults often migrate upstream and use smaller tributaries of rivers or lakes for spawning; unimpeded access to these areas is therefore important.  The eggs and very young stages (known as alevins) remain within the gravel for many weeks during the winter months until they are ready to emerge.

Swim-up fry
After emerging from the gravel in spring, wild trout fry establish individual territories.  They need cover in the river edges or on the bed, sheltered from strong currents, but where there is an adequate supply of food.

Parr
As young trout grow they occupy shallow riffles and runs, where there is plenty of cover in the form of weed or rocks, and an increased supply of food. The water should be cool, clean and well-oxygenated.

Adult trout
Adult trout need space and deeper water, close to a steady supply of food, with plenty of cover in the form of undercut banks, overhanging vegetation, tree roots, weed or rocks.