The counting results include, depending on the method, lists of the algae species, their quantity as biomass (mg / l) and density (algae / ml). The number of algae depends on the amount of nutrients in the water and other environmental factors such as the water conductivity. Usually a sample contains about 40-100 different species. The amount of biomass varies normally between 0,2-2,5 mg/l. The density depends largely on the size of the algae, the smaller the species, the bigger the algae densities.
Various indexes have been designed for phytoplankton, which attempt to simplify the information, but a professional algae expert sees further than those indexes, and can expose this hidden information.
The most comprehensive results of phytoplankton calculations are obtained by using a quantitative calculation method. The results include besides the species list also biomass and density. For required check-ups and monitoring of the waters, counting is always done quantitatively.
The instructions for different methods can be found here: The counting methods of phytoplankton.
The sample can also be examined only qualitatively or semi quantitatively, resulting only in the species list (qualitative) or besides the species list the estimation of the relative abundances of the species (semi quantitative). These methods are suitable when only an overview of phytoplankton is needed.