Spatial Variability of Phytoplankton and Environmental Factors in a Temperate Estuary of South América (Atlantic Coast, Argentina)

A spatial and temporal study on data collected along the longitudinal gradient of the Principal Channel of Bahía Blanca estuary, Argentina, was carried out during 1992–1993. At nine stations, phytoplankton abundance, chlorophyll a (Chl-a ) concentration, inorganic nutrient levels, Secchi disk depth,...

Descripción completa

Detalles Bibliográficos
Autores: Popovich, Cecilia Angelines, Marcovecchio, Jorge Eduardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/27391
Acceso en línea:http://hdl.handle.net/11336/27391
Access Level:acceso abierto
Palabra clave:Bahia Blanca Estuary
Phytoplankton Dynamics
Historical Data
Environmental Conditions
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:A spatial and temporal study on data collected along the longitudinal gradient of the Principal Channel of Bahía Blanca estuary, Argentina, was carried out during 1992–1993. At nine stations, phytoplankton abundance, chlorophyll a (Chl-a ) concentration, inorganic nutrient levels, Secchi disk depth, euphotic depth:mixing depth ratio ( Z eu : Z m ), salinity and temperature were recorded. Phytoplankton abundance, Chl- a concentration and nutrient levels decreased towards the outer zone of the estuary. The inner zone (stations 1 and 2), which was characterized by high turbidity, high nutrient concentrations and high Z eu : Z m ( 4 0.16, [critical mixing ratio]), registered the highest phytoplankton abundance and Chl- a concentrations. Temporal variability of data was also noteworthy in this zone. The highest biomass values thus corresponded to June, July, August and the beginning of spring (18 m g Chl- a L 1 and 9 10 6 cells L 1 ) concomitantly with a diatom bloom. In the middle zone (stations 3–6), a strong phytoplankton biomass decrease was observed and it coincided with both deep-mixed depths and low Z eu : Z m ( o 0.16). The outer zone (stations 7–9), which was characterized by low phytoplankton biomass values and low nutrient levels all along the year, was the area mostly influenced by waters from the adjacent continental shelf. In view of the above, it can be concluded that the most important primary production in the Bahı ́ a Blanca would be produced in the shallow inner zone during winter, being the spatial reach of the phytoplankton biomass principally limited to estuarine waters. Presumably, less than 5% of such biomass may reach the coastal area of the estuary.