RUBBISH

Lakes and rivers are often polluted because drains from towns and factories empty into them. And factories sometimes dump very harmful chemicals into the water. The chemicals poison the water. Wildlife cannot easily survive in it. Ocean-going tankers sometimes empty tankfuls of oily water into the sea. When this happens,great patches of oil are left floating on the sea's surface. If a fish swallow the oil,or if their gills become clogged up, they die. Birds land on the sea and the oil clogs up their feathers so that they cannot fly. Unless the oil is cleaned off the birds will die.