The document discusses various types and causes of water pollution. Water pollution occurs when harmful substances contaminate bodies of water due to human activities. Different types of water pollution include microbiological, chemical, oxygen-depleting substances, nutrients, and oil pollution. Major causes are domestic and agricultural wastewater, dumping of litter in oceans, and nuclear waste from industrial processes. Water pollution leads to toxic water and diseases in humans and death of marine animals. The document recommends ways to prevent water pollution such as proper fertilizer use, participating in cleanups, spreading awareness, and planting more trees.