In the temperate ocean (the mid-latitudes), there are two annual algal blooms: one in the spring, and one in the fall. Explain why these blooms occur and why we don't see blooms in the winter and...

In the temperate ocean (the mid-latitudes), there are two annual algal blooms: one in the spring, and one in the fall.
Explain
why these blooms occur and why we don't see blooms in the winter and summer. (Hint: think about the controls on primary productivity)