SS4.13 Water Quality of Lakes, Rivers and Coastal Zones
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
 
Rios, J, V, University of Texas at El Paso, El Paso, USA, jvrios@utep.edu
Walsh, E, J, University of Texas at El Paso, El Paso, USA, ewalsh@utep.edu
Gardea-Torresdey, J, L, University of Texas at El Paso, El Paso, USA, jgardea@utep.edu
 
IMPACT OF MULTI-METAL SOLUTIONS ON A BASAL MEMBER OF A RIVERINE FOOD WEB (ROTIFERA: PLATIONUS PATULUS)
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The Rio Grande has been impacted by anthropogenic activities along its entire course. Runoff and wind deposition of smelting residues contribute to pollution in this river. Here we provide evidence of how the interaction of some elements (As, Cr, Cu, Ni, Pb, Zn) at different concentrations (10-150 ppb) alter rotifer population dynamics. Plationus patulus collected from the Rio Grande were cultured for >20 generations before exposure to multi-element solutions. Preliminary analyses reveal that smaller population sizes were observed in rotifers exposed to a combination of at least four high concentration elements. High Cu concentration (50 ppb) seems to be most important in decreasing population growth under these conditions. Treatments that resulted in highest population sizes contained a low Cu concentration as well as a low concentration of most other elements. Reproductive mode of rotifers was monitored in all treatments. Interaction of metals in aquatic environments can significantly decrease the population size and cause shifts of reproductive patterns of lower trophic level consumers that may negatively affect overall productivity of lotic systems.