Biotoxicological assesment of Daphnias using pollutants from mining activity

The assessment evaluates aquatic ecosystems organisms known as Daphnia (water fleas), in the presence of pollutants that come from mining activity, by the applications of biotoxicological tests. The daphnias were chosen due to the fact, that they are very sensitive to contaminants and have an important role in aquatic ecosystems. They feed on smaller species and provide food for many fishes. The biotoxicological tests were applied in two particular cases, in both cases the Median Lethal Concentration (LC50) was obtained for daphnias in short tests (96 hours), using for this determination, the probit analysis curve. In the first case it was used a single pollutant (Copper solution 1000 ppm), where It was determined that the LC50 was 3.3 µg/L; in the second case there were used several contaminants (river as a receptor), and it was determined that the LC50 was 59%, It means that 59% is the river water and the 41% is distilled water.Este estudio tiene por objetivo la evaluación de organismos de ecosistemas acuáticos como Daphnias (pulgas de agua), ante la presencia de contaminantes que provienen de la actividad minera, mediante la aplicación de ensayos biotoxicológicos. Las daphnias se han escogido porque son muy vulnerables a contaminantes y cumplen un papel importantísimo en los ecosiste-mas acuáticos, debido a que consumen otros organismos más pequeños y sirven de alimento a diversos peces. Los ensayos biotoxicológicos fueron aplicados para dos casos en particular, en ambos se obtuvo la concentración letal media (CL50) para daphnias en pruebas cortas (96 h), utilizando para su determinación la curva de análisis Probit. En el primer caso, se evaluó a un solo contaminante (solución de cobre de 1000 ppm), encontrándose que la CL50 es de 3.3 µg/L; en el segundo caso se evaluaron varios contaminantes (cuerpo receptor) y se encontró que la CL50 es de 59 %; es decir, que el 59 % es el agua del cuerpo receptor y el 41 % corresponde al agua destilada