Q8. how can an increase in algal population size kill fish? algae clogs the gills of the fish, preventing them from breathing. algae clogs the mouths of the fish, preventing them from eating the algae use up the oxygen in the water as they photosynthesize. when the algae die, their decomposers use up the oxygen in the water

answer:

the algae uses up the oxygen in the water as they photosynthesize.

explanation:

algae does not actually harm the bodies of the fish by clogging external openings. the algae uses up oxygen, which the fish also need to breathe. the fish will suffocate in the water, from a lack of oxygen. the decomposers of dead algae add nutrients to the water, letting more algae grow.

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