title: Phosphorus sorption experiments and the potential for internal phosphorus loading in littoral areas of a stratified lake.
abstract: The exchange of phosphorus (P) during the resuspension of sediments into shallow (oxic) waters of deep stratified lakes is regulated by equilibrium dynamics. In this study, we compared the P-sorption characteristics of sediments from 17 shallow and deep littoral sites in an oligo-mesotrophic lake. Zero Equilibrium P Concentration (EPC(0)) ranged from 0.2 to 5 microgPL(-1). EPC(0) did not vary with sediment characteristics, but increased with increasing sediment-to-water ratios (SWR). Buffering capacity also increased with increasing SWR up to 1 gL(-1), at which point P concentrations were buffered almost perfectly. Therefore, internal P loading in littoral areas may depend primarily on the intensity and duration of sediment resuspension instead of sediment composition, and is expected to be spatially and temporally patchy. Maximum P-sorption capacity (S(max)) varied with chemical composition of the sediments, but was generally low, indicating a limited capacity of littoral sediments to retain external inputs of P.
authors.affiliation: Department of Ecology and Evolutionary Biology, Ramsay Wright Zoological Labs, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5. helene.cyr@utoronto.ca
authors.forename: Hélène
authors.initials: H
authors.lastname: Cyr
authors.forename: Shelley K
authors.initials: SK
authors.lastname: McCabe
authors.forename: Gertrud K
authors.initials: GK
authors.lastname: Nürnberg
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000032:analysis; D002118:Calcium / Q000032:analysis; D005618:Fresh Water / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis*; D007501:Iron / Q000032:analysis; D008345:Manganese / Q000032:analysis; D009864:Ontario; D009930:Organic Chemicals / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D009930:Organic Chemicals; D010758:Phosphorus; D008345:Manganese; D000535:Aluminum; D007501:Iron; D002118:Calcium