Factors Affecting Primary Production

Abstract

The rate of primary production of a parcel of a marine environment depends on light and on the chemical conditions provided by the physics of water masses. There is thus a complex coupling of physics, chemistry, and biology in marine environments. In this chapter we start in reductionist fashion by examining how light, nutrients, and temperature affect primary producers. We focus on two major variables—light and nutrients—and their role in determining primary production. Grazing and sinking, the other major factors affecting producers, are discussed in Chapters 5 and 13. The interactions of controlling factors that determine seasonal cycles are discussed in Chapter 15. We end this chapter with some examples of how the motion of water masses affects production in the ocean through its effect on availability of light, nutrients, and temperature.