A fleshy herb of the wet margins of brooks, streams and ditches, Brooklime can be seen all year-round and provides shelter for tadpoles and sticklebacks.

Native oysters are a staple of our seas and our plates - but our love of their taste has lead to a sharp decline all around the UK.

Living up to its name, the bullhead has a characteristically large, flattened head and a tapering body. Look out for it in fast-flowing, stony rivers and streams.

The silvery dace can be seen gathering in large shoals in lowland rivers and streams. It is a member of the carp family and looks very similar to the chub, but is smaller.

Water-cress has become so popular as a salad addition that it is now cultivated on a wide scale. In the wild, it grows in shallow, fast-flowing streams and is an indicator of clean water.

A member of the buttercup family, Common water-crowfoot displays white, buttercup-like flowers with yellow centres. It can form mats in ponds, ditches and streams during spring and summer.

The silvery chub can be seen gathering in large shoals in lowland rivers and streams. It is a member of the carp family and looks very similar to the dace, but is larger and has redder fins.

As the name suggests, the Common medium stonefly is found in gravelly upland rivers and streams, often on bankside stones and plants. There are 34 species of Stonefly in the UK, which are hard to…

A common and diminutive fish, the minnow can be found in freshwater streams, rivers and lakes across the country. Look out for the dark stripe along its flank and the red bellies of the males.