Tag Archives: research findings

Example 44- Graduate science student

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.’

Source:

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:

Schindler’s experiments on Lake 227, a small unproductive lake, involved adding 0.34 g of P as Na2HPO4 and 5.04 g of N as NaNO3 per square meter, over 17 weeks. Over those 17 weeks, the fertilization caused a severalfold increase in the phytoplankton and shifted the dominant bacteria towards species of cyanobacteria, despite the phosphorus concentrations rarely exceeding 0.05 ug/L P-PO4. This experiment also gave evidence that phosphorus accumulates in the bottom sediments based on their mass-balance calculations (D. W. Schindler et al., 1971)⁠.

Writer’s comment:

Here I was summarizing… paraphrasing this paper to describe the experiment they had done. This statement here is a summary of the experiment and this statement here is a paraphrase of the experiment.

Example 41- Graduate science student

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.’

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