Question

An ecologist noticed a pond with many dead fish. He also noticed that the pond was covered in algae and there were many farms nearby. Which of the following is the most likely cause of the dead fish?

a) High levels of pollution
b) Overfishing
c) Algae bloom
d) Farm runoff

Answer 1

Farm runoff, which includes chemicals such as fertilizers, is the most likely cause of the dead fish in the pond. The excessive growth of algae due to the runoff depletes oxygen in the water, harming aquatic organisms like fish.

Step-by-step explanation:

The most likely cause of the dead fish in the pond is d) Farm runoff. Farm runoff, which includes chemicals such as fertilizers, can enter bodies of water through runoff and cause excessive growth of algae. The algae use up oxygen in the water, leading to low oxygen levels that can kill aquatic organisms like fish. This process is known as eutrophication and is a major source of water pollution.