Question

An open-air waste water treatment plant is flooded by rain. the rainwater and the waste run into a nearby creek. the organic wastes are very high in biological oxidation demand (bod) which means the bacteria in the waste need a lot of oxygen. what is the best hypothesis to explain why many fish might die as a result of this event?

Answer 1

The answer is eutrophication. This is caused by the high oxygen demand by the bacteria breaking down the waste in the water. This reduces the oxygen levels in the lake and therefore makes the waters anoxic. The lake becomes unable to support other organisms, such as fishes, in the lake that require oxygen for respiration.