title: Examination of reactive phosphate fluxes in an eutrophicated coastal area.
abstract: Reactive phosphate (RP) fluxes over sediment in an eutrophic bay were obtained under different conditions. The results were assessed together with water column, sediment solid, and liquid-phase parameters. The RP fluxes ranged from 0 to 1,300 μgatP × m(-2)d(-1) day depending on the sediment site and other variables. At stations with relatively high net RP fluxes, the clay fraction was >3% and disproportionate with salinity, which explained why the RP effluxes decreased by inhibition of the organic coating on particulate matter with increased SO(4) (-2) ions and good competition of RP anions with SO(4) (-2). The RP flux in Fe/RP ratios >2 in surface water decreased to approach a minimum asymptotically, which was thus defined with a hyperbolic curve to determine the maximum rate of the RP flux (J(RP)). The [RP(porewater)](initial)/[RP(ambient)] (initial) ratios were suggested to govern the net RP flux regionally, so the critical value where the RP flux turns positive could indicate eutrophication with Chl-a values <500 μg/g. So, this study investigated the phosphate fluxes between sediment and water column and determined the factors influencing the RP fluxes in the inner bay of Izmir.
authors.affiliation: Fisheries Faculty, Department of Hydrobiology, Ege University, 35100 Izmir, Turkey. ebru.yesim.koksal@ege.edu.tr
authors.forename: Ebru Yesim
authors.initials: EY
authors.lastname: Ozkan
authors.forename: Baha
authors.initials: B
authors.lastname: Buyukisik
mesh_terms: D004784:Environmental Monitoring; D005068:Eutrophication; D019015:Geologic Sediments / Q000737:chemistry; D010710:Phosphates / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D014421:Turkey; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D010710:Phosphates; D014874:Water Pollutants, Chemical