Water pollution

Very HigH HigH low clean

Pollution in our rivers is a serious problemRivers provide most of the water we need for our homes, schools, factories and farms

and they are home to a wide range of plant and animal life.

One of the best ways of testing for pollution is to look at the type of animal life in the water. Different creatures die at different levels of pollution. When certain species are missing,

it indicates how badly a river or stream is polluted.

Rat-tailed Maggot

Heavily polluted water often looks clear but contains little or no life.Oxygen levels – very poor

Water Louse Bloodworm Freshwater Caddisfly Cranefly Shrimp Larva Larva

Riffle Beetle Mayfly

NymphStoneflyNymph

Freshwater Limpet

BlackflyLarva

Small creatures reappear as the pollution is diluted. Oxygen levels - poor

Smallfish,largerinsectsandsomewaterbirds start to reappear.Oxygen levels - good

Clean unpolluted water supports an abundance of plants and animals which live in, on or near the water.Oxygen levels – excellent

As the water flows further from the pollution source the oxygen levels start to rise. Flowing through reeds, tumbling over rocks or falling down waterfalls puts essential oxygen back into the water. The more dissolved oxygen there is in the water, the more creatures can live in it.

Pollution poisons river life and reduces the dissolved oxygen in the water. Dissolved oxygen is vital, as all forms of water life need it to survive.

POLLUTION LEVELS