Effects of Copper on Nitrogen Fixation and Growth of Blue-Green Algae in Natural Plankton Associations

1982 ◽  
Vol 39 (12) ◽  
pp. 1636-1641 ◽  
Author(s):  
Wayne A. Wurtsbaugh ◽  
Alexander J. Horne
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Carbon Fixation ◽  
Copper Toxicity ◽  
Inhibitory Effect ◽  
Clear Lake ◽  
Blue Green Algae ◽  
Limiting Nutrient ◽  
Effect Of Copper ◽  
Pigment Accumulation

Copper toxicity bioassays were conducted on six stages of the spring Aphanizomenon flos-aquae bloom in eutrophic Clear Lake, California. Major variables tested were nitrogen fixation, carbon fixation, pigments, and cell numbers. Inhibition of nitrogen fixation, carbon fixation, and pigment accumulation increased linearly between 10 and 30 μg Cu/L. Higher concentrations produced little additional toxicity. In contrast, there was a stimulatory effect of copper, especially on nitrogen fixation, at the very low level of 2 μg/L. There was no inhibitory effect of copper on nitrogen fixation without a comparable or greater effect on carbon fixation or chlorophyll a. Other algae growing with the Aphanizomenon bloom were not affected by additions of copper up to 20–30 μg Cu/L, but were affected at the 50–100 μg/L level.Key words: algae, algicide, blue-green algae, copper, cyanobacteria, metal, limiting nutrient, nitrogen fixation, photosynthesis, phytoplankton, toxicity

Iron in Eutrophic Clear Lake, California: Its Importance for Algal Nitrogen Fixation and Growth

1983 ◽  
Vol 40 (9) ◽  
pp. 1419-1429 ◽  
Author(s):  
Wayne A. Wurtsbaugh ◽  
A. J. Horne
Keyword(s):  
Nitrogen Fixation ◽  
Large Volume ◽  
Carbon Fixation ◽  
Algal Growth ◽  
Clear Lake ◽  
Blue Green Algae ◽  
Green Algal ◽  
Chlorophyll Production ◽  
Low Nitrogen

Clear Lake, California, is warm, shallow, polymictic, and eutrophic. During 1975, levels of dissolved (< 0.45 μm) iron in all three basins of Clear Lake were always low (15–30 μg∙L−1) and decreased to 2 μg∙L−1 during the major bloom of Aphanizomenon flos-aquae. Nitrogen fixation (acetylene reduction) rates of the blue-green algal populations were stimulated as much as 500% above control levels by iron additions in laboratory and in situ large-volume bioassays. Carbon fixation rates and chlorophyll a levels were also significantly stimulated by iron additions, but usually less rapidly and to a lesser extent than N2 fixation. Additions of nitrate stimulated carbon fixation and chlorophyll production but inhibited increases in nitrogen fixation. Phosphate additions either had no effect or produced a mixture of stimulation or depression of all three variables. The bioassays indicate that the growth of blue-green algae and other algae in Clear Lake is usually directly limited by combined nitrogen and occasionally by iron or phosphorus. Low iron levels aggravate the effects of low nitrogen by limiting nitrogen fixation, thus reducing blue-green algal growth.

scholarly journals Studies on Nitrogen Fixation by Blue-Green Algae

1942 ◽  
Vol 19 (1) ◽  
pp. 78-87
Author(s):  
G. E. FOGG
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Anabaena Cylindrica ◽  
Fixed Nitrogen ◽  
Blue Green Algae ◽  
Combined Nitrogen

1. Anabaena cylindrica Lemin. has been obtained in pure unialgal bacteria-free culture. 2. Due precautions having been taken against contamination by other organisms and error due to absorption of fixed nitrogen from the atmosphere, this alga has been shown to possess the capacity of fixing nitrogen. 3. Nitrogen fixation does not take place in the presence of a sufficient quantity of readily available combined nitrogen.

Is the Heterocyst the Site of Nitrogen Fixation in Blue-green Algae?

Nature ◽  
1968 ◽  
Vol 220 (5169) ◽  
pp. 810-812 ◽  
Author(s):  
P. FAY ◽  
W. D. P. STEWART ◽  
A. E. WALSBY ◽  
G. E. FOGG
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Blue Green Algae

Blue-green algae in southern Australian rangeland soils.

1989 ◽  
Vol 11 (2) ◽  
pp. 67 ◽  
Author(s):  
RW Rogers
Keyword(s):  
Nitrogen Fixation ◽  
Climatic Change ◽  
Green Algae ◽  
Soil Conservation ◽  
Soil Surface ◽  
Soil Samples ◽  
Blue Green Algae ◽  
Range Condition ◽  
The Subject ◽  
Arid Rangelands

Blue-green algae (Cyanobacteria) are imponant to the ecology of arid rangelands as sources of nitrogen and as soil stabilizers, yet have been the subject of little comment or investigation in Australia. To provide information on their distribution soil samples were collected from 136 locations in rangeland areas of southem Australia and cultured to permit the identification of the blue-green algae present. Blue-green algae were found in 134 of the samples. The species represented include several apparently capable of nitrogen fixation, and all produce a gelatinous sheath which can bind soil panicles to produce soil-surface crusts. It is likely that lichens and blue-green algae are important for the ecology of arid rangelands now, and if climatic change destroys the lichens which are very heat sensitive when wet, blue- greens may become even more significant in soil conservation and the maintenance of pasture productivity. Both lichens and blue-green algae merit inclusion in assessments of range condition.

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