title: The use of dinoflagellate cysts to separate human-induced from natural variability in the trophic state of the Po River discharge plume over the last two centuries.
abstract: To obtain insight into the natural and/or human-induced changes in the trophic state of the distal portion of the Po River discharge plume over the last two centuries, high temporal resolution dinoflagellate cyst records were established at three sites. Cyst production rates appear to reflect the natural variability in the river's discharge, whereas cyst associations reflect the trophic state of the upper waters, which in turn can be related to agricultural development. The increased abundances of Lingulodinium machaerophorum and Stelladinium stellatum found as early as 1890 and 1920 correspond to the beginning of the industrial revolution in Italy and the first chemical production and dispersion of ammonia throughout Europe. After 1955, the increased abundances of these species and of Polykrikos schwartzii, Brigantedinium spp. and Pentapharsodinium dalei correspond to agriculturally induced alterations of the hypertrophic conditions. A slight improvement in water quality can be observed from 1987 onward.
authors: MARUM/Fachbereich 5-Geowissenschaften, University of Bremen, Leobener Straße, D-28334 Bremen, Germany. Electronic address: zonnev@uni-bremen.de.
authors: Karin A F
authors: KAF
authors: Zonneveld
authors: MARUM/Fachbereich 5-Geowissenschaften, University of Bremen, Leobener Straße, D-28334 Bremen, Germany.
authors: Liang
authors: L
authors: Chen
authors: MARUM/Fachbereich 5-Geowissenschaften, University of Bremen, Leobener Straße, D-28334 Bremen, Germany; Faculty of Science, Alexandria University, Baghdad St., Moharam Bay 21511, Alexandria, Egypt.
authors: Rehab
authors: R
authors: Elshanawany
authors: Institute of Environmental Physics, University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany.
authors: Helmut W
authors: HW
authors: Fischer
authors: MARUM/Fachbereich 5-Geowissenschaften, University of Bremen, Leobener Straße, D-28334 Bremen, Germany.
authors: Mirja
authors: M
authors: Hoins
authors: Faculty of Science, Alexandria University, Baghdad St., Moharam Bay 21511, Alexandria, Egypt.
authors: Mohammed I
authors: MI
authors: Ibrahim
authors: Institute of Environmental Physics, University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany.
authors: Daniela
authors: D
authors: Pittauerova
authors: MARUM/Fachbereich 5-Geowissenschaften, University of Bremen, Leobener Straße, D-28334 Bremen, Germany.
authors: Gerard J M
authors: GJM
authors: Versteegh
mesh_terms: D004141:Dinoflagellida / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification; D004784:Environmental Monitoring; D020387:Food Chain; D006801:Humans; D007558:Italy; D045483:Rivers / Q000737:chemistry*; D014876:Water Pollution / Q000706:statistics & numerical data*