Manipulating and Measuring Growth and Biomass in Simple to Complex Systems and a Curve for All Reasons

At the core of understanding growth are two fundamental concepts (that apply not only to phytoplankton but to all organisms): first, understanding the rate of growth of an organism is not the same as measuring its biomass, and second, rates of biological processes (including growth) increase with increasing concentration of the limiting substrate up to a point of “saturation” where limitation is overtaken by some other factor such as another substrate or physiological limitations. This chapter uses these fundamental concepts to introduce how growth of phytoplankton is measured, how cell division occurs, and how growth can be manipulated and quantified. Different culture systems, from laboratory to mesocosms, are introduced along with their associated experimental considerations.