INVESTIGADORES
GUINDER Valeria Ana
artículos
Título:
Particulate suspended matter concentrations in the Bahía Blanca Estuary, Argentina: implication for the development of phytoplankton blooms
Autor/es:
GUINDER, VALERIA A.; POPOVICH, CECILIA A.; PERILLO, GERARDO M.E.
Revista:
ESTUARINE COASTAL AND SHELF SCIENCE
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Año: 2009 p. 157 - 165
ISSN:
0272-7714
Resumen:
The inner zone of
the Bahía Blanca Estuary is shallow, nutrient-rich and turbid. Tidal
energy and water turbulence strongly affect the water column resulting
in a well-mixed structure and high concentrations of suspended
sediment. The phytoplankton community is mostly dominated by diatoms
and the annual pattern has been characterized by a recurrent
winter-early spring bloom. Here, we investigated to what extent the
temporal variations of suspended particulate matter (SPM) regulate the
phytoplankton blooms in the head of the estuary by light-limitation.
Sampling was done on a fortnightly basis (weekly during the blooming
season) at a fixed station in the inner zone of the estuary from
January 2007 to February 2008. SPM concentrations and light extinction coefficients (k)
in the water column were significantly correlated and showed
relatively lower values during the phytoplankton maximal biomass levels.
During winter, SPM and k reached values of 23.6 mg l-1 and 0.17 m-1 which were significantly lower than the annual means of 77.6 mg l-1 and 2.94 m-1,
respectively. The particulate organic matter (POM) concentration was
significantly correlated with the calculated phytoplankton biomass
although the contribution of the latter to the total POM was rather low.
Both, POM and biomass, had maximal values during winter (21.8 mg l-1 and 393.5 mg C l-1) and mid summer (24.3 mg l-1 and 407.0 mgC l-1), with cell densities up to 8 x 106 cells l-1 and chlorophyll a up to 24.6 mg l-1. Our results suggest that the
decrease of SPM concentrations in the water column with a concomitant
increase in the penetration of solar radiation seems to be one of the
main causes for the development of the phytoplankton winter bloom in
the Bahía Blanca Estuary.