Microzooplankton (protozoans and micrometazoans) are abundant in the sea and play significant roles in pelagic food webs. Estimating microzooplankton biomass, however, is a tedious and relatively specialized process. Techniques are needed to augment traditional approaches. It is known that algal pigment content is roughly proportional to biomass. The hypothesis of the present study is that carotenoid pigment content in microzooplankton is also correlated with biomass. The objectives of this research are to test this hypothesis and to identify environmental forcing functions responsible for variability in the relationship. Findings, to date, support the hypothesis, but elaboration is necessary. Experiments will be undertaken to identify the influence of food availability, light intensity and spectral characteristics, and population growth on the pigment:biomass relationship. In addition, the analytical method, which involves HPLC, will be modified to increase carotenoid resolution. The improved method will provide data at higher rates than presently possible, and may allow discrimination between micrometazoan and protozoan biomass.
