title: Spatial and seasonal variability of pico-, nano- and microphytoplankton at the bottom seawater in the north coast of Sfax, Eastern Mediterranean Sea.
abstract: In the frame of the Taparura Project, we studied the distribution of pico-, nano- and microphytoplankton communities in relation to environmental variables at 18 stations sampled during four coastal cruises conducted between October 2009 and July 2010 at the bottom, on the north coast of Sfax (Tunisia, Eastern Mediterranean Sea). The restoration effect on coastal ultraphytoplankton (<10 μm) and microphytoplankton (<200 μm) was investigated using conventional flow cytometry and inverted microscopy. Flow cytometry analysis of ultraphytoplankton resolved six groups (Prochlorococcus, Synechococcus, nanoeukaryotes and three distinct subgroups within picoeukaryotes). In addition to these autotrophic groups, two unknown groups were characterised on the north coast. Picophytoplankton abundance shifted from a summer dominance of Synechococcus to a dominance of picoeukaryotes and Prochlorococcus during spring. Nanoeukaryotes were the most abundant in spring. Microphytoplankton was resolved into five groups, labelled Bacillariophyceae, Dinophyceae, Cyanobacteriae, Euglenophyceae and Chlorophyceae. A total of 90 microphytoplankton species were identified in all stations, with an overwhelming abundance of large diatoms, a typical trait of benthic communities (Coscinodiscus sp., Grammatophora sp., Navicula sp., Pleurosigma sp., Striatella unipunctata …). Results collected in this study are favouring a beneficial impact on the ecosystem of the Sfax north coast restoration achieved by the Taparura Project.
authors.affiliation: Unité Biodiversité et Ecosystèmes Aquatiques, Université de Sfax, B.P.1171, 3000, Sfax, Tunisia.
authors.forename: Amira
authors.initials: A
authors.lastname: Rekik
authors.affiliation: CNRS/INSU, IRD, Institut Méditerranéen d'Océanologie (MIO), Aix Marseille Université, Université de Toulon, 163 Avenue de Luminy, Case 901, 13288, Marseille Cedex 09, France. michel.denis@univ-amu.fr.
authors.forename: Michel
authors.initials: M
authors.lastname: Denis
authors.affiliation: Unité Biodiversité et Ecosystèmes Aquatiques, Université de Sfax, B.P.1171, 3000, Sfax, Tunisia.
authors.forename: Sami
authors.initials: S
authors.lastname: Maalej
authors.affiliation: Unité Biodiversité et Ecosystèmes Aquatiques, Université de Sfax, B.P.1171, 3000, Sfax, Tunisia.
authors.forename: Habib
authors.initials: H
authors.lastname: Ayadi
mesh_terms: D003247:Conservation of Natural Resources; D017753:Ecosystem; D008522:Mediterranean Sea; D010839:Phytoplankton; D012621:Seasons; D012623:Seawater / Q000382:microbiology*; D062206:Spatial Analysis; D014416:Tunisia
keywords: Autotrophic microbial assemblage; Eastern Mediterranean Sea; Flow cytometry; Gulf of Gabès; North coast of Sfax; Taparura Project