blue-green_algae has definitions from the field of biology
1
[ noun ] (biology) predominantly photosynthetic prokaryotic organisms containing a blue pigment in addition to chlorophyll; occur singly or in colonies in diverse habitats; important as phytoplankton

Synonyms

cyanobacteria

Used in print

(Ross E. McKinney and Howard Edde, "Aerated...)

It was possible to maintain aerobic conditions in the pond by regular additions of sodium_nitrate until the temperature decreased and the algae population changed from blue-green to green_algae .

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