Eutrophication

Eutrophication is like when your mom puts too much food in your goldfish's bowl and the water gets really dirty and yucky. When people put too many nutrients from things like fertilizers and sewage into a body of water, like a lake or river, it can cause eutrophication. These nutrients make plants, like algae, grow really fast and take over the water. When it gets bad, there can be so much of these plants that they block the sun from reaching the lower parts of the water and use up all the oxygen. This can make it hard for fish and other animals to live in the water. Just like how your goldfish can get sick if its water is too dirty, animals in the water can get sick or even die if eutrophication gets too bad.