MP9 Metals and Bioaccumulation
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall

(RAM-1117-854528) Depuration of some metals by Daphnia pulex, a commercial product restauration project.

Ramírez-Romero, P¹, Guzman-Martinez , M. C.¹, Barceló-Quintanal, I. D.², Bussy-Beaurain , A. L.², Guerrero Romero, L.R.¹, ¹ Universidad Autónoma Metropolitana- Iztapalapa, Mexico, D. F., Mexico² Universidad Autónoma Metropolitana- Azcapotzalco, Mexico, D.F., Mexico

ABSTRACT- For years Daphnia pulex, was exploited as a commercial product by the indigenous community of Tlachaloya, in the State of Mexico. This organism grew in abundant numbers in the Jose Antonio Alzate dam and was sold to Japan as a supplement for animal feed. In the 40s decade an industrial corridor was established in Toluca and the Lerma River was severely contaminated with high loads of organic matter and metals among others. As the years passed the Daphnia production fell and the contamination of the dam is so severe nowadays, that only few organisms can survive in this environment. However, due to its hydrological characteristics, the central zone of the dam has better water quality and a restauration project has been proposed to better the water quality and reestablish this organism production. The objective of this work was to evaluate the depuration capacity of Daphnia pulex, in order to establish the water metal concentrations that have to be achieved in the dam in order to have a healthy population that can be exploited. Acute toxicity, bioaccumulation and depuration tests were performed with organisms extracted from the dam. These organisms are more resistant than others that come from less contaminated environments and efficiently bioaccumulate metals. The depuration process to achieve exportation quality is too expensive nowadays and the metals concentrations would have to drop at least in half in order to make it profitable

Key words: Daphnia pulex, Bioaccumulation, Depuration, Metals