The composition of particulate phosphorus: A case study of the Grand River, Canada

Biogeochemical Processes and Microbial Dynamics Governing Phosphorus Retention and Release in Sediments: A Case Study in Lower Great Lakes Headwaters

“…In addition, determination of suspended sediment EPC 0 values showed that the fine particulate phase could be a much greater accumulator and source of SRP than bed sediments, and that in many cases, suspended sediment at Big Creek was at or near saturation with respect to dissolved P. For example, suspended sediment EPC 0 values at Big Creek were found to be as high as 200 times greater that corresponding bed sediment values, and suspended sediment collected during the 2020 interval was measured to have an EPC 0 over 2000% greater than corresponding surface water SRP, constituting a major internal P-source. It’s possible that suspended sediment is an overlooked source of internal P in suspension at Big Creek, as has been the case in other regional watersheds of the lower Great Lakes (Shinohara et al 2018 ; Markovic et al 2020 ).…”

Periphyton Phosphorus Uptake in Response to Dynamic Concentrations in Streams: Assimilation and Changes to Intracellular Speciation

“…Freeze-dried biomass samples were extracted for solution 31 P NMR analysis following the protocol detailed by Cade-Menun . This method has been shown to be capable of detecting and quantifying a broad variety of organic P forms in diverse environmental samples including phosphonates, orthophosphate monoesters, orthophosphate diesters, and polyphosphates. − Briefly, 0.2 g of dry biomass was mixed with 25 mL of extraction solution (0.25 M NaOH and 0.05 M Na 2 EDTA) and shaken at ∼21 °C for 4 h. The mixture was then centrifuged at 2300 g for 20 min, the supernatant extracted by pipet, neutralized to pH 7 through the addition of ∼2.5 mL of 3 M HCl to avoid the degradation of polyphosphates and filtered to 0.45 μm (Nylon membrane) . A 1 mL aliquot of the filtrate was collected for analysis of Al, Ca, Fe, Mg, Mn, and P concentration by ICP-OES to assess P recovery from dry biomass and concentrations of paramagnetic ions (Fe and Mn) which influence NMR experiments.…”

Characterizing bioavailable phosphorus concentrations in an agricultural stream during hydrologic and streambed disturbances

“…Long-term monitoring of the western Lake Erie tributaries has indicated an increase in SRP inputs to the lake (Jarvie et al 2017 ; Koltun 2021 ), and while long-term estimates of BAP entering the lake have been measured using chemical extractions (Baker et al 2014 ), these estimates do not account for organic forms of P that are biologically available. The presence of organic P has been highlighted by Shinohara et al ( 2018 ) using NMR spectroscopy to show that a majority of the bioavailable P entering Lake Erie from the Grand River (a Canadian tributary to Lake Erie dominated by agricultural land use) was from particulate organic phosphorus. Thus, our simple bioassay could improve characterization of bioavailable P entering Lake Erie, and enhance our understanding of the extent and timing of eutrophication more generally.…”