Frogbit looks like a mini water-lily as it floats on the surface of ponds, lakes and still waterways. It offers shelter to tadpoles, fish and dragonfly larve.

The tiny, brown-and-white sand martin is a common summer visitor to the UK, nesting in colonies on rivers, lakes and flooded gravel pits. It returns to Africa in winter.

A tall and robust species of sedge, the Great fen-sedge has long leaves with sawtooth edges. It forms dense stands in lowland fens and around lakes.

The greenshank breeds on the boggy moors and ancient peatlands of Scotland. But it can be spotted elsewhere in the UK as it passes through on migration - look around lakes, marshes and the coast…

A handsome fish, the tench has olive-green flanks, powerful fins and distinctive red eyes. It can be found in lowland lakes and slow-flowing rivers around the UK.

Look for the White water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and massive, white flowers float at the water's surface.

Look for the Yellow water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and cupped, yellow flowers float at the water's surface.

A recent colonist to South East England, the metallic-green Willow emerald damselfly spends much of its time in the willow and alder trees that overhang ponds, lakes and canals.

Also known as the 'green drake mayfly', the common mayfly can be found around unpolluted wetlands, such as lakes and rivers. It has transparent, lacy wings and three long 'tails…