Identification of Common Noxious Cyanobacteria: Part 1 – Nostocales

This report was produced for the Urban Water Research Association of Australia, a now discontinued research program.

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Identification of Common Noxious Cyanobacteria: Part 1 – Nostocales

Report No UWRAA 29

June 1991


This report contains the results of a 12 month investigation of the taxonomy of noxious blue-green algae (Cyanophyta/Cyanobacteria) in Australian water supplies, funded by the Urban Water Research Association of Australia.

The purpose of the project was to morphologically characterise common noxious or nuisance forms of cyanobacteria in Australian water supplies and to establish criteria by which they can be recognised and reliably identified by light microscopy. Particular attention was directed to those forms which are able to form water blooms or unsightly surface scums and may impair water quality by the production of toxins or taste and odour compounds.

The rationale for this project was based on the need to differentiate between inoffensive and noxious forms of cyanobacteria for efficient water quality management. Water supply authorities throughout Australia require a practical guide to the identification of troublesome cyanobacteria encountered locally and need to be able to relate them to existing taxa in the published literature. A final report has been prepared in the form of a practical reference, incorporating descriptions, illustrations, photo-micrographs and identification keys to assist laboratory personnel involved in phytoplankton monitoring.

Cyanobacterial blooms can adversely affect the suitability of water for human consumption, stock watering and recreational use. As there are indications of increasing abundance of these blooms in Australian waters, this issue was seen to be of national significance.

This report, representing Part I of the project, provides taxonomic descriptions of commonly occurring planktonic and bloom-forming cyanobacteria from the family Nostocaceae (order Nostocales) in South Australia, Victoria, New South Wales and south-eastern Queensland. A total of 20 recognised taxa are described from 5genera (Anabaena, Anabaenopsis, Aphanizomemon, Cylindrospermopsis and Nodularia) and approximately 200 original illustrations are provided.

Identification keys are provided for genera within the family Nostocaceae and to species or subspecies level within each genus. None of the described taxa are endemic to Australia and most are considered cosmopolitan. Several taxa of the family Nostocaceae are described for the first time in Australia.

A second report (Part II), currently in preparation, will provide taxonomic descriptions for reported taxa of the families Microcystaceae (order Chroococcales) and Oscillatoriaceae, Phormideaceae and Pseudanabaenaceae (order Oscillatoriales).

Further study is required to resolve problems in the classification of certain described forms which do not fit the morphological description of existing taxa and to determine whether discernible morphological differences of described taxa represent actual genetic differences.

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