Seasonal variations in ocean temperatures can impact the populations of living organisms in the ocean. how would a phytoplankton population be affected by these changes?

lower ocean temperatures allow for phytoplankton to bloom, which increases the phytoplankton population.

A phytoplankton population would be affected by these changes by increasing the population of the phytoplankton. Low temperature of the ocean would allow for the phytoplanktons to bloom or reproduce. Therefore, high temperatures would slow down growth.  This is because when water is warm there would be less mixing between the water layers and the nutrient rich water.