Farmers fertilize their crops with harmful fertilizers that contain nitrates and phosphates. These fertilizers create runoff from the crop that contain these nutrients. The runoff eventually finds its way off the farm...
The runoff from the farms eventually finds its way into bodies of water like this lake. It gets there through sources like rainwater and streams. When this runoff gets into a lake, it has very negative affects on the lake such as...
This is fertilizer runoff from the nearby farm into the lake.
When excess amounts of phosphates and nitrates seep into the water, the process of eutrophication begins. Aquatic plants being to flourish and an algae bloom forms. These plants feed on the nutrients and grow larger.
The algae bloom blocks the sunlight from reaching the aquatic plants underneath the surface of the water. This lack of sunlight causes the plants to die because they can't preform their natural processes.
As the algae bloom starts to die, decomposing bacteria starts to enter the scene. Their job is to decompose the dying algae. As they decompose the algae, they use up dissolved oxygen that is vital to the survival of the organisms in the water. The bacteria reproduces rapidly.
Dead Algae Bloom
Since there is little amount of dissolved oxygen in the water, fish cannot survive. The fish and other organisms start to die as the bacteria continues to use up the oxygen. When the fish die, they decompose them and use even more of it.