1. Pesticides, fertilizers, and animal waste from the agriculture industry are contaminating our lakes, waterways, and oceans. We’re also dumping over 180 million tons of toxic chemicals and other pollutants from industrial and mining practices into the world’s lakes, rivers, and oceans every year.
2. Rain washes fertilizers, pesticides, and contaminated soil into rivers and streams, where it creates excessive amounts of nitrogen and phosphorous in the water. This excess of nutrients stimulates the growth of plants in lakes, taking up additional oxygen from the water and eventually killing organisms, insects and other aquatic life.
3. Pollution due to excess nutrients in freshwater or saltwater also results in algal blooms, which is a thick sludge or discoloring that covers the surface of a body of water. These toxic blooms pose a threat by depriving the water of oxygen, which is essential to the survival of aquatic species.
4. A lack of sufficient oxygen kills off aquatic life and plants, resulting in dead zones and threatening the survival of the ecosystem. Land animals, birds, and humans can also be harmed by the contaminated water, or by consuming fish or shellfish that lived in contaminated water.
5. Animal waste from factory farming contributes to water pollution when the large, open-air lagoons that house wastewater from the farms leak and contaminate local water supplies, or when runoff from the farms makes its way into nearby lakes and waterways.
6. Animal waste from factory farms also contains hormones which, when introduced into water systems, can cause reproductive problems in fish.
7. As technology improves, scientists are able to detect more pollutants, and at smaller concentrations, in Earth’s freshwater bodies. Containing traces of contaminants ranging from birth control pills and sunscreen to pesticides and petroleum, our planet’s lakes, rivers, streams, and groundwater are often a chemical cocktail.
8. Beyond synthetic pollution, freshwater is also the end point for biological waste, in the form of human sewage, animal excrement, and rainwater runoff flavored by nutrient-rich fertilizers from yards and farms.
9. Types of Water Pollution – a toxic substance is a chemical pollutant that is not a naturally occurring substance in aquatic ecosystems. The greatest contributors to toxic pollution are herbicides, pesticides and industrial compounds. Organic pollution occurs when an excess of organic matter, such as manure or sewage, enters the water. When organic matter increases in a pond, the number of decomposers will increase.