HOW MANY SPECIES OF ALGAE ARE THERE?

TLDR

Algae are estimated to number between 30,000 and over 1 million species, with diatoms alone possibly exceeding 200,000, and the field faces a decline in taxonomists needed for systematic work. The study aims to refine the algal species count by analyzing phylum- and class-level data from the AlgaeBase database. The authors applied a conservative counting strategy to AlgaeBase phylum- and class-level species data, accounting for taxonomic uncertainties, to derive the estimate. They estimate 72,500 algal species, with about 44,000 names likely published and 33,248 recorded in AlgaeBase as of June 2012.

Abstract

Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on-line taxonomic database AlgaeBase (http://www.algaebase.org). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species, names for 44,000 of which have probably been published, and 33,248 names have been processed by AlgaeBase to date (June 2012). Some published estimates of diatom numbers are of over 200,000 species, which would result in four to five diatom species for every other algal species. Concern is expressed at the decline and potential extinction of taxonomists worldwide capable of improving and completing the necessary systematic studies.