Answer:
The respiratory system and the circulatory.
Explanation:
The respiratory system brings in the oxygen and the circulatory system brings all of the oxygen through out the body.
An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels, to more harmful effects like blocking sunlight from reaching other organisms, causing a depletion of oxygen levels in the water, and, depending on the organism, secreting toxins into the water.
