This "pond" is on farmlandand the process explained in the next few slides explain what happens to it.
Slide: 2
Fertilizer
In order for the plants to grow the farmers have to use fertilizer. The fertilizer is comprised of three main chemicals. Nitrogen, phosphorus, amd potassium. When combined they can make plants grow at an accelerated rate.
Slide: 3
Transportation
It is very hard to measure out exactly how much fertilizer plants need. The soil differs throughout the land so most farmers just put extra fertilizer to be safe. The fertilizer that is not used is the washed away by rain. THe fertilizer is carried by runoff into the pond. The fertilizer then starts to move its way into the vegetation in the pond. The plants in the pond the become overgrown.
Slide: 4
Formation of a algae bloom
The fertilizermakes the algae at the bottom of the pond over grow. The algae takes over the pond and can be harmful. When the algae is so thick it creates a blanket over the pond it is called an algae bloom. They can be very harmful to the organisms living in the pond.
Slide: 5
Effects of a algae bloom
The algae bloom blocks all sunlight from the plants at the bottom of the pond. Without sunlight plants can't perform photosynthesis thereforethey can't produce oxygen. The DO in the pond will decrease and the animals living in the pond with start to die off. The fish don't have any oxygen so they will die of hypoxia which is a lack of oxygen to the body.
Slide: 6
Dead zones
When all the algae from thealgae bloom die they sink to the bottom of the pond. They are then striped by bacteria. It takes a lot of oxygen to perform that process making the DO levels in the water even lower. This makes the water inhabitable. If any organizm where to try to live in those conditions they would die of hypoxia.