Distribution and ecology of Pseudo-nitzschia species (Bacillariophyceae) in surface waters of the Weddell Sea (Antarctica)

The distribution of six Pseudo-nitzschia species and their relationship with environmental conditions were studied for the first time in a vast zone of the Weddell Sea (∼61-77°S, Antarctica). Both qualitative and quantitative phytoplankton samples, collected during summer 2004, were examined using l...

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Detalles Bibliográficos
Autores principales: Almandoz, G.O., Ferreyra, G.A., Schloss, I.R., Dogliotti, A.I., Rupolo, V., Paparazzo, F.E., Esteves, J.L., Ferrario, M.E.
Formato: JOUR
Materias:
Antarctica
Diatoms
Phytoplankton distribution
Pseudo-nitzschia
Weddell Sea
abundance
community composition
confluence
diatom
ecology
environmental conditions
flagellate
ice cover
morphology
morphometry
phytoplankton
spatial distribution
species-area relationship
surface water
Atlantic Ocean
Scotia Sea
Southern Ocean
Bacillariophyceae
Bacillariophyta
Mastigophora (flagellates)
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_07224060_v31_n4_p429_Almandoz
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:The distribution of six Pseudo-nitzschia species and their relationship with environmental conditions were studied for the first time in a vast zone of the Weddell Sea (∼61-77°S, Antarctica). Both qualitative and quantitative phytoplankton samples, collected during summer 2004, were examined using light and scanning electron microscopy. Phytoplankton abundance and composition showed great variability along our study area. Diatoms were the most conspicuous phytoplankton group in the northern area while small flagellates were generally dominant in the southern stations. The genus Pseudo-nitzschia was broadly distributed and significantly contributed to total diatom densities. A marked contrast in Pseudo-nitzschia species distribution was observed in three main zones divided by the Weddell Front (WF) and the Antarctic Slope Front (ASF). P. subcurvata and P. turgiduloides were the most abundant species in the neritic Weddell Sea zone, south of the ASF, mainly near the ice-edge in shallower waters and in conditions of long photoperiod. In contrast, P. prolongatoides and P. lineola dominated north of the ASF; the first was associated with deeper and nutrient-rich waters whereas the latter showed a weak relation with environmental variables examined. Finally, P. turgidula and P. heimii were mostly observed in the Weddell-Scotia Confluence Zone in the warmest and far from ice covered waters, north of the WF. A brief morphological Pseudo-nitzschia species description is given in the Appendix, including morphometrics and pictures. © 2007 Springer-Verlag.

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