Biovolume calculation for pelagic and benthic microalgae

Microalgal biovolume is commonly calculated to assess the relative abundanc e (as biomass or carbon) of co-occurring algae varying in shape and/or size . However, a standardized set of equations for biovolume calculations from microscopically measured linear dimensions that includes the entire range o f microalgal shapes is not available yet, In comparison with automated meth ods, the use of microscopical measurements allows high taxonomic resolution , up to the species level, and has fewer sources of error. We present a set of geometric shapes and mathematical equations for calculating biovolumes of >850 pelagic and benthic marine and freshwater microalgal genera, The eq uations are designed to minimize the effort of microscopic measurement. The similarities and differences between our proposal for standardization and previously published proposals are discussed and recommendations for qualit y standards given.