A note on El Niagara, a polluted reservoir in Aguascalientes, Mexico

Abstract

235Plankton, physical, chemical, and microbiological data, were taken from the polluted reservoir El Niagara during 1990. Chlorella spp and Euglena spp were the dominant phytoplankters. Zooplankton diversity and density were low: Brachionus spp, Asplanchna sieboldi, Moina affinis and Daphnia similis appeared seasonally; protozoans were present all year. Ten years earlier, the water quality and biota of the reservoir, then alreay degraded, were much better than today.

Determination of toxicity levels in the San Pedro River Watershed, Aguascalientes, Mexico

“…[11] This reservoir has many problems due to the toxicity provoked by anthropogenic activities. [12,13] In Aguascalientes we have been using several biomarkers to conduct a preliminary evaluation of the content of toxicity of diverse discharges of the industries in the State. [14] Although the San Pedro River and its tributaries have been highly contaminated through time, in recent years construction of several water treatment plants around the city of Aguascalientes to treat wastewater entering the river have slowly improved its water quality.…”

The Use of Aquatic Invertebrate Toxicity Tests and Invertebrate Enzyme Biomarkers to Assess Toxicity in the States of Aguascalientes and Jalisco, Mexico

“…The State of Aguascalientes, like the rest of Mexico is not indifferent to problems related to toxicity (Limon et al, 1989;Flores-Tena and Silva-Briano, 1995). Aguascalientes is one of the provinces, where zooplankton has been wellcharacterized (Silva-Briano, 1992;Rico-Martinez and Silva-Briano, 1993;Dodson and Silva-Briano, 1996).…”

Water Quality of a Reservoir and Its Major Tributary Located in East-Central Mexico

“…Some studies on water quality have been carried out in Mexican reservoirs [10,13,14,15,16]. However, other reservoirs and their tributaries with ecological and economic importance have been poorly studied; with regard to the Atlanga Reservoir, this is the largest and most important of the 16 reservoirs located in the State of Tlaxcala, Mexico, and water from this reservoir is used mostly for supplying agricultural irrigation, mainly in the months of April to August, due to that precipitation in the state is low, with a annual mean of around 700 mm [17].…”

“…It is known that deterioration of reservoirs due to anthropogenic factors or natural processes affects the water quality, impairing its future use and also the protection of aquatic life [ 7 , 11 ]; in addition, the characteristics of the water in the tributaries could be an indicator that exerts an impact on these systems or that influences the spatial variations [ 5 , 6 , 12 ]. Some studies on water quality have been carried out in Mexican reservoirs [ 10 , 13 , 14 , 15 , 16 ]. However, other reservoirs and their tributaries with ecological and economic importance have been poorly studied; with regard to the Atlanga Reservoir, this is the largest and most important of the 16 reservoirs located in the State of Tlaxcala, Mexico, and water from this reservoir is used mostly for supplying agricultural irrigation, mainly in the months of April to August, due to that precipitation in the state is low, with a annual mean of around 700 mm [ 17 ].…”