At the surface of the oceans, NPP is most often limited by nutrients, particularly nitrogen and iron.Moving downward through the ocean, the major limiting factor is usually
A) nitrogen.
B) phosphorus.
C) light.
D) acidity.
E) salinity.

Question

Quizplus · Accepted Answer

As one moves downward through the ocean, light becomes the major limiting factor for NPP. This is because sunlight can only penetrate a certain distance into the ocean, and below that depth, there is not enough light for photosynthesis to occur. While nutrients may still be limiting at these depths, their availability is not the primary factor controlling NPP. Therefore, choice C (light) is the best answer.

At the Surface of the Oceans, NPP Is Most Often