what effect does eutrophication have on the amount of oxygen disolved in a body of water? why?

Answer 1

it will decrease the amount of oxygen in water. Eutrophication is happening when fertiliser such as phosphate is poured into lake or any water body and this enrich the minerals content inside. Therefore algae will grow rapidly in the water body [ algae need only minimum requirement to grow ]. When that much algae exist and perform metabolism in the lake, they will uptake lots of oxygen inside at a fast rate until even the rate of dissolving of oxygen from atmosphere into water cant catch up with the rate of cousuming. As a result, thw amount of oxygen decrease.