Chapter 7: Primary Production
Paul Webb
Learning Objectives
After reading this chapter you should be able to:
- define primary production, gross and net production, new and regenerated production
- identify some of the major organisms involved in oceanic primary productivity
- define a red tide
- explain how certain phytoplankton can cause toxic blooms
- identify the major requirements for primary production to occur
- explain how light availability and thus primary production changes with depth
- define the concept of compensation depth in relation to primary production
- identify the major nutrients needed for primary production
- recreate and explain the general depth profiles for nutrients in the ocean, and the factors responsible for those curves
- describe the seasonal patterns in productivity in polar, tropical, and temperate regions, and the factors responsible for those patterns
While this book does not delve too deeply into marine biology topics, one biological process that is crucial to an understanding of oceanography is primary production. Oceanic primary production obviously forms the base of marine food webs, but it also produces about half of the oxygen that we breathe in terrestrial systems. Furthermore, you cannot fully understand the profiles of dissolved gases (section 5.4) or the distribution of (section 12.6) without considering the roles played by primary production.
This chapter begins by defining primary production, before introducing the organisms responsible for that productivity. We will then examine the requirements for marine productivity, which leads to a discussion of how primary production changes seasonally and along latitudinal gradients.
sediment created from the remains of organisms (12.3)
