Study of a “bloom” of the oil‐rich alga <i>Botryococcus braunii</i> in the Darwin River Reservoir

Abstract

Abstract A “bloom” of the freshwater alga Botryococcus braunii Kützing appeared in the Darwin River Reservoir in 1976. At the time of algal sampling, the "bloom" was estimated at 1500 ton and possibly double this mass at a maximum cell concentration. The alga is characterized by a high liquid hydrocarbon content, sufficient to cause flotation of the algal colonies. This report is an examination of the waters of the reservoir and of the characteristics of the alga. Observations are included on the formation of a material known as Coorongite, a rubbery complex produced by the drying of colony aggregates at the shoreline. Earlier reports of “blooms” of B. braunii are reviewed in relation to this study.