Particulate suspended matter concentrations in the Bahía Blanca Estuary, Argentina: Implication for the development of phytoplankton blooms

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 an...

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Detalles Bibliográficos
Autores: Guinder, Valeria Ana, Popovich, Cecilia Angelines, Perillo, Gerardo Miguel E.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2009
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/56317
Acceso en línea:http://hdl.handle.net/11336/56317
Access Level:acceso abierto
Palabra clave:Argentina
Bahía Blanca Estuary
Light Availability
Phytoplankton Bloom
Suspended Particulate Matter
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descripción
Sumario: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 μg C l-1) and mid summer (24.3 mg l-1 and 407.0 μg C l-1), with cell densities up to 8 × 106 cells l-1 and chlorophyll a up to 24.6 μg 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.