Problems pertaining to harmful microalgae are being worked on and discussed by many categories of researchers: ecologists, taxonomists, toxicologists, by persons involved in monitoring the environments for harmful effect of toxic algae, by politicians, journalists, etc. It is a source of confusion that the scientific ('Latin') names of the algae sometimes change when the organisms become available for more detailed studies due to improved methodology or after establishment of the organisms in pure cultures, and such changes may give rise to misunderstandings.
This site has the following aims:

1. to provide a catalogue of the world's toxic microalgal species
2. to promote stability in toxic microalgal nomenclature
3. to act as a tool for higher taxonomic revisions and regional monographs
4. to provide a base link for other online databases that use toxic microalgal nomenclature

The list contains at the moment species producing toxins or toxic effects, and a few species suspected to form toxins. It does not include species that cause harm due to biomass, mucus, morphology (spines etc), as these potentially represents a vast number of species. The names and data on all toxic species appear as WoRMS checked names (see www.marinespecies.org) whereas names of harmful species, which potentially can be any plankton species, are not necessarily checked but are always valid names.
To provide sufficient expert knowledge for maintaining the list, we have formed an editorial committee to whom the queries on particular taxa should be addressed.
The Committee hopes to extend the list during the coming years, to include additional information, including illustrations.
At the Fourth Session of the IOC Intergovernmental Panel on Harmful Algal Blooms, Vigo, Spain, 30 June-2 July 1997, it was decided to establish a Task Team on Algal Taxonomy with the aim of providing an agreed reference list of harmful algal species, including correct citation of the author(s), date of valid publication, and a list of synonyms.
During the HAB 2000 Conference in Hobart, Tasmania, February 2000, the Committee met and discussed the contents and the format of the list. Following additional discussions over the e-mail, it was decided to prepare all entries in the list as follows:

1. Correct name according to the International Botanical Code of Nomenclature, followed by author(s) and year it was given its present name
2. Basionym (the first name applied to the species, including year)
3. Reference to the article in which the species was first described
4. Reference to the article in which the species was given its present name
5. Type locality
6. Synonyms, including year
7. Main harmful effects
8. Up to (usually) 3 references with information on toxicity, toxins or toxic effects
9. Notes (if applicable)

The predecessor and basis for this list is the on-line version of the IOC Taxonomic Reference list of Toxic Plankton Algae, which was provided in cooperation with and hosted by the Department of Biology, University of Copenhagen and was completed in early 2002. The cyanobacteria (blue-green algae) are presently being added.