Water pollution is the contamination of water sources by substances which make the water unusable for drinking, cooking, cleaning, swimming, and other activities. Pollutants include chemicals, trash, bacteria, and parasites. All forms of pollution eventually make their way to water. Water pollution has many causes. One of the biggest causes is fertilizer in runoff. Runoff dissolves fertilizer as it flows over farm fields, lawns, and golf courses. It carries the dissolved fertilizer into bodies of water. More dissolved fertilizer may enter a body of water at the mouth of a river, but there... Show more Water pollution is the contamination of water sources by substances which make the water unusable for drinking, cooking, cleaning, swimming, and other activities. Pollutants include chemicals, trash, bacteria, and parasites. All forms of pollution eventually make their way to water. Water pollution has many causes. One of the biggest causes is fertilizer in runoff. Runoff dissolves fertilizer as it flows over farm fields, lawns, and golf courses. It carries the dissolved fertilizer into bodies of water. More dissolved fertilizer may enter a body of water at the mouth of a river, but there is generally no single point where this type of pollution enters the water. That's why this type of water pollution is called nonpoint-source pollution. When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. The algae out-compete other water organisms and may make the water unfit for human consumption or recreation. Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (“without oxygen”). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water can't support life. A very large dead zone exists in the Gulf of Mexico. Nutrients carried into the Gulf of Mexico by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. Show less
Water pollution is the contamination of water sources by substances which make the water unusable for drinking, cooking, cleaning, swimming, and other activities. Pollutants include chemicals, trash, bacteria, and parasites. All forms of pollution eventually make their way to water.
Water pollution has many causes. One of the biggest causes is fertilizer in runoff. Runoff dissolves fertilizer as it flows over farm fields, lawns, and golf courses. It carries the dissolved fertilizer into bodies of water. More dissolved fertilizer may enter a body of water at the mouth of a river, but there is generally no single point where this type of pollution enters the water. That's why this type of water pollution is called nonpoint-source pollution. When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. The algae out-compete other water organisms and may make the water unfit for human consumption or recreation. Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (“without oxygen”). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water can't support life. A very large dead zone exists in the Gulf of Mexico. Nutrients carried into the Gulf of Mexico by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms.
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