A graduate student in civil engineering

Source text:

‘Addition of 0.34 g P as Na2HPO+ and 5.04 g N as NaNO3 per square meter to a small unproductive Canadiari Shield lake over a period of 17 weeks caused a several fold increase in phytoplankton standing crop, and a change in dominant species from. Chrysophyceae to Chlorbphyta. Reactive phosphate concentrations remained at undetectable levels in the epilimnion after fertilization, und inorganic nitrogen concentrations remained low’ Most of the added phosphorus and niirogen was-rapidly taken up by phytoplankton and sedimented with the seston. Although concentrations of total COz decreased to less than 20 pmoles/liter and pH values increised to greater than 9 in late summer, a high standing crop of ph) ‘toplankton was maintained. No marked increase in the rate of phytoplankton production was noticed, Experiments in polyethyiene containers suspended in the lake during this period of low total Cdz indicated that iarbon was not limiting to algal production, except possibly at algal standing crois in excess of 100 pg/liter chlorophyll o, and that phosphorus was the primary limiting nutrient.’

Source:

Schindler, D., & Fee, E. (1974). Experimental Lakes Area: Whole-Lake Experiments in Eutrophication. Journal of the Fisheries Research Board of Canada, 31, 937–953. 11

Schindler, D. W., Armstrong, F. A. J., Holmgren, S. K., & Brunskill, G. J. (1971). Eutrophication of Lake 227 , Experimental Lakes Area, Northwestern Ontario, by Addition of Phosphate and Nitrate. Journal of the Fisheries Research Board of Canada, 28, 1763–1782.

Writer’s text:

Scheindler et al., (1974; 1971) showed through their work on Lakes 226 and 227, that phosphorus is the limiting nutrient in eutrophication and that carbon necessary for biomass growth could be fixed from the atmosphere.

Writer’s comment:

Well, because this is to come to this one sentence there are papers and papers of research…this is the original research for this case finding. [It is] useful for someone to know that I have summarized this experiment and cited it as opposed to paraphrasing someone else’s work.