Mercury accumulation by the fresh water alga [formula omitted][formula omitted

Abstract

The deposition of mercury in the environment continued unchecked until recently when accumulations of this toxicant were found to be potentially dangerous to man. Since outbreaks of mercury poisoning among people were first positively diagnosed in the early 1960s, Japan, Canada, Sweden and the US have actively engaged in research and established regulations to prevent further human poisoning. Much research has been devoted to assessment of the accumulation of mercury in fish and aquatic birds which may be consumed directly by man. Yet relatively little work has been directed at mercury uptake by lower aquatic organisms. At the base of the aquatic food web are the algae from which the majority of non-photosynthetic aquatic organisms derive most of their energy. It is therefore important to explore the pathways by which mercury may enter the food web at this lower trophic level. In the present study, laboratory cultures of the unicellular, fresh-water, green alga Selenastrum capricornutum were utilized to examine uptake of inorganic mercury. Selenastrum was chosen as the test organism due to its wide natural distribution and because it has previously received intensive use as a bioassay organism in limnological and ecological studies. 3 references, 2 figures.