title: Daily availability of nutrients and metals in a eutrophic meso-tidal coastal lagoon (Obidos lagoon, Portugal).
abstract: This baseline reports daily variations of physico-chemical parameters, nutrients and metals in water of two sites [eutrophic conditions (BB) versus reference (LL)] in Obidos coastal lagoon (Portugal). Dissolved oxygen in BB varied between 40% saturation levels (night) and 190% (daylight). NH(4)(+), PO(4)(3-) and ratios to Al of Mn, Fe and Pb in suspended particulate matter increased during the period of lower oxygenation, indicating exportation of nutrients and metals from the sediment to water at night. At LL, O(2) values oscillated always around 100%. PO(4)(3-) and Mn/Al ratio at LL were always lower than at BB and no increases were found during the night. The input of PO(4)(3-) and Mn provided from the sediment at BB during the night could surpass the contribution of freshwater discharges. PCA confirmed the separation of most samples from BB and LL. These results pointed to the importance of assessing chemical conditions over day-night cycles.
authors.affiliation: IPIMAR - National Institute of Biological Resources, Av. Brasília, 1449-006 Lisbon, Portugal. patbio@ipimar.pt
authors.forename: Patrícia
authors.initials: P
authors.lastname: Pereira
authors.forename: Hilda
authors.initials: H
authors.lastname: de Pablo
authors.forename: Susana
authors.initials: S
authors.lastname: Carvalho
authors.forename: Carlos
authors.initials: C
authors.lastname: Vale
authors.forename: Mário
authors.initials: M
authors.lastname: Pacheco
mesh_terms: D005068:Eutrophication; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry*; D009792:Oceans and Seas; D011174:Portugal; D012623:Seawater; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical