 Most phytoplankton are too small to be individually seen with the unaided eye.However, when present in high enough numbers, some varieties may be noticeable as colored patches on the water surface due to the presence of chlorophyll within their cells and accessory pigments (such as phycobiliproteins or xanthophylls) in some species.About 1% of the global biomass is due to phytoplankton.