IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Zooplankton composition and seasonal dynamics from a saline shallow lake: La Salada (Argentina)
Autor/es:
ALFONSO, MARÍA BELÉN; MARÍA CINTIA PICCOLO; GERARDO MIGUEL EDUARDO PERILLO
Lugar:
Chuncheon
Reunión:
Congreso; GLEON 17; 2015
Institución organizadora:
GLEON
Resumen:
Lakes from the Pampean region are shallow, polymictic and typically eutrophic environments. Water residence time and salinity are highly fluctuating and its dynamic is strongly affected by both, seasonal climate fluctuations and human activities. Because of its intermediate position in food webs, structure and dynamics of the zooplankton may vary in these systems in response to these changes. The aim of this study was to determine the composition and temporal dynamics of the zooplankton community in a saline shallow lake, La Salada, located in the South of Buenos Aires Province, Argentina (39°27´S - 62°42´W). The main affluent is an artificial channel derived from the Colorado River. Monthly samples were taken between 2012 and 2014. Main physicochemical and meteorological parameters were measured in situ. Subsurface water samples were collected for chemical and biological analysis (seston, nutrients, chlorophyll a). Zooplankton samples were taken with a 47 µm mesh net and preserved in 4 % formaldehyde. The most representative species were Bracionus plicatilis and Synchaeta kitina (rotifera) and Apocyclops sp. among the copepods. Total zooplankton abundances varied between 2.8 ind L-1 (winter) and 1307 ind L-1 (summer). Water level fluctuations affected salinity values, mainly in winter when water from the channel was introduced into the lake. Plankton abundances responded to seasonal temperature variations but it is also seem to be affected by the changing conditions in precipitation, depth and salinity between 2013 and 2014. Variability of precipitations in the study area will be important to consider when proposing accurate water level managements for this saline and shallow ecosystem.