『Abstract
　We tested the hypothesis that there would be measurable losses of phosphorus (P) from surficial sediments of Upper Klamath Lake (UKL), Oregon, if sediments were a source of P during an algal bloom. We compared concentrations of total and forms of P at various depths in cores collected before and after the onset of a large Aphanizomenon flos-aquae bloom. Concentrations of inorganic P were determined in extraction solutions of MgCl2 (1 M, pH 8), citrate-dithionite-bicarbonate, and 1 M HCl. Sediments below 2 cm were dominated by residual P which is defined as total P minus inorganic P. During the study period, data from the top 2-cm of sediment indicated (a) significant decrease in total P concentration, primarily associated with iron oxyhydroxides at one site, and (b) significant increase in total P concentration associated with residual P at a second site. Data from two other sites indicated no net changes in concentrations of total P.

Keywords: Phosphorus fractionation; Residual phosphorus; Cyanophyte; Eutrophic; Shallow lake; Metals』

1. Introduction
2. Methods
　2.1. Study sites
　2.2. Sediment geochemistry
　2.3. Statistical analysis
3. Results
　3.1. Study sites
　3.2. Sediment geochemistry
　3.3. Statistical analysis
4. Discussion
5. Conclusions
Acknowledgements
References