%0 Journal Article
%T Epilithic diatoms (Bacillariophyceae) as indicators of water quality in the Upper Lerma River, Mexico Diatomeas epil¨ªticas como indicadores de la calidad del agua en la cuenca alta del r¨ªo Lerma, M¨¦xico
%A Virginia Segura-Garc¨ªa
%A Enrique A. Cantoral-Uriza
%A Isabel Israde
%A Nora Maidana
%J Hidrobiol¨®gica
%D 2012
%I Universidad Aut¨®noma Metropolitana, Unidad Iztapalapa
%X The upper Lerma River is the most economically important basin of Mexico because it is the region where 80 % of the commercial activity of the country takes place, with 3500 industries, 750,000 Ha of irrigated land and 14 cities with populations over 100,000 inhabitants. Despite this relevance, little or no waste water treatment is done in the basin, which results in high contamination levels. The present paper deals with the taxonomy and ecology of epilithic diatoms collected at 11 sites in the basin in the dry and post-rainy seasons of the 2003-2005 period. This is the first study in an environmental direction of the diatoms of the upper Lerma River basin and the information generated will be used to propose, in the short-term, a Lerma River diatom index (IDL), supporting water quality monitoring programs. 178 taxa were recognized, of which 112 taxa (63%) were cosmopolitan or widely distributed. The genera with most species were Nitzschia (34), Navicula (19), Gomphonema (15), and Pinnularia (11). The dominant species in the studied locations and study period were Eolimna subminuscula(Manguin) Moser, Lange-Bertalot etMetzeltin, Gomphonemaparvulum(K¨¹tzing) K¨¹tzing, Navicula veneta K¨¹tzing, Nitzschia capitellata Hustedt, N. sublinearis Hustedt, N. umbonata (Ehrenberg) Lange-Bertalot and Sellaphora pupula (K¨¹tzing) Mereschkowsky, which are characterized as tolerant to ¦Á-mesosaprobic to polysaprobic conditions, and to high nitrogen content. Trends in distribution of diatom species in the sampling sites were explained by variations in environmental parameters such as depth, conductivity, pH, temperature, and total dissolved solids. La cuenca alta del r¨ªo Lerma es la m¨¢s importante de M¨¦xico desde el punto de vista econ¨®mico, ya que en ella ocurren el 80 % de las actividades comerciales del pa¨ªs, con 3500 industrias diversas, 750,000 hect¨¢reas de tierras de riego y 14 ciudades con poblaciones de m¨¢s de 100,000 habitantes. El escaso o nulo tratamiento de las aguas residuales, trae como consecuencia una elevada contaminaci¨®n. Este trabajo abord¨® el estudio taxon¨®mico y ecol¨®gico de diatomeas epil¨ªticas colectadas en 11 localidades de ¨¦sta cuenca, entre los a os 2003-2005. Se trata del primer estudio con una orientaci¨®n ambiental que se realiza sobre diatomeas de la cuenca alta de este r¨ªo, y la informaci¨®n generada permitir¨¢ proponer en el corto plazo un ¨ªndice diatomol¨®gico para el R¨ªo Lerma (IDL), que posibilite emprender programas de monitoreo de la calidad del agua. Se reconocieron 178 especies, de las cuales 112 taxones (63 %) fueron de amplia distribuci¨®
%K Diatomeas
%K Bacillariophyta
%K R¨ªo Lerma
%K calidad ambiental
%K M¨¦xico
%K Diatoms
%K Bacillariophyta
%K Lerma River
%K environmental quality
%K Mexico
%U http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-88972012000100003