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

Authors

  • Belén Martín Miguez Universidade de Vigo, Facultad de Ciencias
  • L. Fariña-Busto Universidade de Vigo, Facultad de Ciencias
  • F. G. Figueiras Instituto de Investigacións Mariñas, C.S.I.C.
  • F. F. Pérez Instituto de Investigacións Mariñas, C.S.I.C.

DOI:

https://doi.org/10.3989/scimar.2001.65s165

Keywords:

estuarine circulation, succession, box model, Gymnodinium catenatum, Chaetoceros spp., Thalassiosira spp., Ría de Vigo

Abstract


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

Downloads

Download data is not yet available.

Downloads

Published

2001-07-30

How to Cite

1.
Martín Miguez B, Fariña-Busto L, Figueiras FG, Pérez FF. Succession of phytoplankton assemblages in relation to estuarine hydrodynamics in the Ría de Vigo: a box-model approach. scimar [Internet]. 2001Jul.30 [cited 2022Dec.8];65(S1):65-76. Available from: https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/701

Issue

Section

Articles