If we do this, it will be a small first step in keeping the whole world's water clean. If we all do a little, it will help a lot. When you raise animals in a small area, the manure builds up, and it runs off into lakes and rivers. It also runs off into places like Westcave. When the manure gets mixed up with the water, algae grows faster.
Manure is rich in nutrients and is often used as a fertilizer.
Too much algae will suck so much oxygen out of the water, plants and animals die. Some U. S. feed lots have more than 100,00 head of cattle. The massive amounts of manure they produce are not always recycled. It often goes into massive pits. After that, it is spread over big fields.