The document discusses the main causes and effects of water pollution. It states that water pollution comes from human sewage, industrial waste, oil spills, farm runoff, and plastic waste entering waterways and oceans. These pollutants make their way up the food chain and can poison both wildlife and humans. The document also outlines some international agreements to limit pollution from ships and prevent dumping of hazardous materials, as well as recommendations for individuals to reduce waste and reuse materials to help address the problem of water pollution.