Succession of phytoplankton assemblages in relation to estuarine hydrodynamics in the Ría de Vigo: a box-model approach

摘要: SUMMARY: Two phytoplankton succession events (September-October 1993 and March 1994) in the Ria de Vigo were studied relation to their hydrodynamic context. By means of a circulation box model we calculated horizontal vertical residual fluxes as well budgets associated with them. This allowed us assess importance two factors involved selection processes: one (dependent upon physical dispersion) biogeochemical (involving all other processes such growth, mortality grazing). The first period was characterised by downwelling event which produced reversal estuarine pattern (horizontal velocity = 4 km d -1 downward velocities up 9 m d-1). provided suitable conditions for blooming Gymnodinium catenatum favoured its capacity swim, while diatom community almost disappeared. second corresponded an upwelling → relaxation sequence. During 6 d-1; upward 12 d-1), Thalassiosira spp. dominant. It is suggested that less energetic velocity=1 < 1 d-1) Chatoceros due lower sinking rate.