Solution:
The large-scale phenomenon known as El Niño has a strong influence on climate, precipitation, and ocean physics on a planetary scale.
During El Niño, the thicker-than-normal layer of warm water in the eastern Pacific cuts off nutrient supplies by reducing upwelling from below. Warm water prevents vertical mixing of water and keeps cooler, nutrient-laden water away from the surface where most life is concentrated.
This produces a decrease in productivity.
So that, we can conclude that the correct answer is
TRUE.
