Over the past decade it has become clear that microzooplankton are important contributors to pelagic food chain processes. Estimating microzooplanktonic biomass is one major difficulty that can possibly be resolved by use of pigment analogs. The carotenoid pigments are easily isolated from microzooplankton by high performance liquid chromatography. Using a wide variety of cultured animals and various culture conditions, the study will address the correlation between tissue carotenoid content and microzooplankton biomass and identify principal sources of variance in the relationship. The study will not only evaluate the usefulness of these pigments as biomass estimators, but will indicate new areas of investigation of pigment biochemistry in pelagic ecology. Fast and in situ measures of food chain interactions are part of the foundation for future long term, untended observations of biological processes in the sea. New techniques with field applicability are necessary for the advancement of biological oceanography, and this study will assess a new method and its sources of error in detail. %%% Close examination of the food chain dynamics of the sea in recent years has shown that much predatory activity and transfer of material involves small organisms not captured by ordinary plankton nets. The organisms are numerous and small making it difficult to establish their quantitative significance in a fast, repeatable way. Since they contain carotenoid pigments which can be extracted and analyzed quickly, the pigment content may be a useful indicator of animal biomass. This possibility will be tested on a variety of organisms grown in the laboratory and collected from the sea.//
