A Method of Analysis of Pigments in Phytoplankton

Phytoplankton (phyto, plant; plankton, wandering) are the free-floating microscopic plant cells, which contain photosynthetic pigments found in both terrestrial and marine environments. They contribute nearly 25% of the total vegetation of the plant. Pigments are chemical compounds which reflect only certain wavelengths of visible light. Because they interact with light to absorb only certain wavelengths, pigments are useful to plants and other autotropic organisms which make their own food using photosynthesis. Its value as a biomass indicator of oceanic microscopic marine plants has been recognized over the years. The inventory of pigments is a key characteristic of phototrophic organisms which is used as a criterion in the classification of autotrophic bacteria. Knowledge of phytoplankton dynamics in the World Ocean is central to the study of marine ecology and biogeochemical processes involved in climate change. Phytoplankton biomass can be estimated by the photosynthetic pigment. Phytoplankton pigment quantification is an integral part of inland water monitoring and general experimental research involving phytoplankton. Chlorophyll a (chl a) concentrations are widely used by plankton ecologists as an alternate for phytoplankton biomass and for estimating primary productivity. Photosynthetic and photoprotective pigments and their relative concentration can provide valuable taxonomical and physiological information of phytoplankton. Because pigment composition can be a reflection of taxonomic composition, presence or absence of certain marker pigments can be used to identify phytoplankton community composition. Pigment composition is an important physiological parameter. The environmental factors such as illumination and nutrient availability are influencing the relative pigment concentration. Phytoplankton pigments were analysed by spectrophotometry and HPLC methods. Both techniques were significant advances because of their sensitivity and ease of measurement.