an increase in fisheries production during upwelling a decrease in larval fish populations during upwelling an increase in algae and phytoplankton during upwelling a decrease in surface water temperatures during upwelling
I gave my students this multiple choice question: Which of the following events along the west coast of the United States provides direct evidence that upwelling brings nutrient-rich waters to the surface?

Only one answer is correct among these 4 choices:
- an increase in fisheries production during upwelling
- a decrease in larval fish populations during upwelling
- an increase in algae and phytoplankton during upwelling
- a decrease in surface water temperatures during upwelling

Could you tell me which one is correct?

an increase in algae and phytoplankton during upwelling