Comparative reservoir limnology in Juramento (Salta) and Salí-Dulce (Tucumán) Basins in Argentina

Abstract

The reservoirs of the upper Juramento basin (Cabra Corral and El Tunal) and the Salí-Dulce basin (El Cadillal, Río Hondo, and Escaba) show certain peculiarities due to their geographical location, basin morphology and limnological features. Such peculiaritieswere compared duringsignificant algal bloom periodsbetween 2002 and 2008, by analyzing the mainphysicochemical parameters and ecological attributes of the phytoplankton assemblagesusing standard methods. Tucumán reservoirs were different in most variables showing higher values of conductivity, nutrients and algal biomass.Regarding the hydrological cycle, El Cadillal exhibited the lowest biomass average (2.74 mg Chl.m-3) during maximum water flows, whereas the Cabra Corral lacustrine zone exhibited the highest biomass average (63.36 mg Chl.m-3) during minimum water flows. For the same period, the Cabra Corral lacustrine zone exhibited lower phytoplankton diversity and richness (1.37 and 9, respectively), in accordance with dinophyte blooms of Ceratium sp. In all reservoirs, the following biological variables showed a significant contrast in the hydrological cycle: highest phytoplankton biomass during minimum water flows (35.68 mg Chl-a m-3) vs. waterfloods (13.68 mg Chl-a m-3) (T = 3.42, P = 0.001). During minimum water flows, richness (14.30 sp.) and equitability (0.51) were lower vs. waterfloods (20.23, 0.59, respectively) (T = 2.36; P = 0.0196), as a result of the allochthonous nutrients provided by the main tributaries.Management of the reservoirs’hydrometric levels during dry season determines the deterioration of the waterquality with increased algal blooms. In order to ensure the systems’ sustainability, eutrophication must be controlledwithprograms to reduce diffuse nutrient loads and to treat residential and agroindustrial effluents, particularly in Sali-Dulce basin.

Aplicación de un índice multimétrico basado en macroinvertebrados bentónicos en un embalse del norte argentino

“…Es reconocido como un ecosistema muy poluído por las actividades industriales, agrícolas, mineras y por la contaminación urbana (Defensoría del Pueblo 2017). Los antecedentes sobre las comunidades biológicas del embalse son muy escasos y se enfocan sobre todo en el fitoplancton (Tracanna et al 1999;Salusso and Moraña 2017;Tiberi et al 2018). El objetivo de este estudio fue analizar la composición y la diversidad de los ensambles de macroinvertebrados bentónicos en relación con la degradación ambiental en el embalse, y aplicar el ICB RES para evaluar la calidad biológica del agua en la zona bentónica.…”

“…El pH básico del agua y los valores de conductividad se relacionan con las características geológicas de la región, rica en rocas calizas y evaporíticas (Pérez Miranda et al 2001;Fernández and Hidalgo 2011). La deforestación aporta gran cantidad de sólidos suspendidos, mientras el ingreso de efluentes con altas cargas orgánicas favorecen el desarrollo de abundante fitoplancton en el embalse (Salusso and Moraña 2017), situaciones que influencian la transparencia al disco de Secchi. Los valores obtenidos se encuentran en el rango que caracteriza a embalses eutróficos (Dodds and Whiles 2010).…”

Definition of water quality variability parameters and dynamics to improve management in a deep canyon type subtropical hydroelectric reservoir

“…As the operation can affect the quality of the water in the reservoir, especially at the time of lower flow and longer residence time, the management of this reservoir operation should be based on knowledge of the system dynamics and reservoir gradients, whenever there are threats to water quality. Adjustments in the effluent flow intensity, in order to reduce the reservoir level and the residence time in these critical events can be efficient ways to avoid undesirable plankton proliferation events (Rossel & De La Fuente, 2015;Salusso & Moraña, 2018).…”