Identify Algae

This page lists resources to assist you to identify freshwater and marine macroalgae.  Follow the links below for more information

Useful websites:
(click on the site name to open the website on a new page)

  • Algaebase (cited as Guiry MD, Guiry GM Algaebase. World-wide electronic publication, National University of Ireland, Galway) is a searchable database of freshwater, terrestrial and subaerial algae, seaweed and seagrass names assembled at the National University of Ireland, Galway by Mike and Wendy Guiry. It also contains an increasing number of images of algae which are useful for checking identifications.
  • Video made on a Freshwater Algae Training Course in Durham, UK, showing projection microscopy used to demonstrate a sample of living planktonic algae. Course organizers: David John and Brian Whitton
  • AlgaeVision is a searchable database on the Natural History Museum (London) website of over 2,500 freshwater algal images.  AlgaeVision is designed to be used in conjunction with The Freshwater Algal Flora of the British Isles
  • Diatom Flora of Britain and Ireland is a project aimed at producing a web-based diatom flora and comprehensive taxonomic review of diatoms from freshwater, brackish and subaerial habitats in the British Isles.  The project involves much original research on problematic groups and description of new species.
  • Coded List of British Freshwater Algae mentions all reliable records of freshwater and terrestrial cyanobacteria and photosynthetic algae in the British Isles (diatoms not updated since 2003). Brackish water and intertidal cyanobacteria are also included as there are recordings of a few species from both freshwater and marine environments. The list is accurate as of November 2014 
  • DARES:  Diatom protocols and PowerPoint presentations on sampling methods. 
  • DIADIST:  Diatom and desmid identification by shape and texture. Searchable/browsable images scanned from Wests’ 5-volumed work on British Desmidiaceae (1904-1923) along with an introduction and useful guide to desmid genera. Includes a comprehensive list of links to other algal and desmid sites.  
  • Protist Information Server:  A Japanese website of over 81,000 images of Protists (including algal groups) with most identified to species and useful for identification.