How does eutrophication yield lower levels of dissolved oxygen?

Question

Where do the oxygen go? Is it consumed by a particular species? Is just not enough being made? Please explain.

Answer 1

Hi, so the biggest thing with eutrophication is that because of the surplus of nutrients, algae blooms in excess on the surface, which means that sunlight gets blocked from reaching the underlying waters. Other plants die because of this lack of sunlight, and then eventually the algae dies too. With all this dead plant material, bacteria in the water go to work decomposing it, and these bacteria consume all the dissolved oxygen as they break down the excessive amount of dead plants, leaving the waters in that area hypoxic (without enough oxygen). Hope this helps!