Physical, chemical and biological variability in the Dr. C. Gelsi reservoir(NW Argentine) : a temporal and spatial approach
With the purpose of understanding the phytoplankton dynamics in two vertical profiles of the Dr. C. Gelsi reservoir (Tucumán, Argentina, monthly samplings were conducted from October 1997 to March 1999 in the limnetic zone and at the intersection of the Salí and Tapia tributary. The reservoir was ch...
| Autores: | , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:27952 |
| Acceso en línea: | https://ddd.uab.cat/record/27952 |
| Access Level: | acceso abierto |
| Palabra clave: | Paràmetres físics i químics Paràmetres biològics Fitoplàncton Embassament Nordest argentí Parámetros físicos y químicos Parámetros biológicos Fitoplancton Embalse Noroeste Argentino Tucumán Physical and chemical parameters Biological parameters Phytoplankton Reservoir Northwestern Argentina |
| Sumario: | With the purpose of understanding the phytoplankton dynamics in two vertical profiles of the Dr. C. Gelsi reservoir (Tucumán, Argentina, monthly samplings were conducted from October 1997 to March 1999 in the limnetic zone and at the intersection of the Salí and Tapia tributary. The reservoir was characterized as warm monomictic, with bicarbonate, chloride, sodium, calcium and/or magnesium waters. In both sites total nitrogen concentration was higher than 1 mg/l, whereas that of orthophosphate reached 0.2 mg/l. Out of the eleven organochlorine pesticides analyzed, the presence mainly of lindane and methoxychlor, with higher concentrations in the warm months was confirmed. Bacterial load values were compatible with water quality standards, and variations in the number of actinomycetes colonies in the sediments were correlated, among other parameters, with dissolved oxygen. In the two zones studied a total of 57 phytoplankton taxa, 49 % green algae, 37 % diatoms, 9 % Cyanobacteria and 5 % dinoflagelates, were identified. Central diatoms (Aulacoseira granulata and Cyclotella meneghiniana) prevailed in the phytoplankton and, in a lesser degree, the other groups, low values of specific diversity being obtained. A principal components analysis based on the absolute abundance of species and on some physico-chemical parameters ordinated the samples of the various levels, this abundance being more evident in the limnetic zone. There was also a tendency to the separation of stratifications from the two consecutive years and homogeneity in the samples from the mixing period was noticed. On the basis of the saprobic index, water quality was from β - α-mesosaprobic to α-mesosaprobic. |
|---|