Determination of lead in samples of zooplankton, water, and sediments in a Mexican reservoir: Evidence for lead biomagnification in lower/intermediate trophic levels?

Abstract

We have determined lead concentration of water, sediment, and zooplankton samples of El Niágara, a reservoir in Aguascalientes, Mexico. Our results include the first report of bioconcentration factor (BCF) obtained in an actual ecosystem (as opposed to the experimental setups in the laboratory) for a rotifer species; Asplanchna brigthwellii (BCF ca. 49 300). The BCF of this predatory zooplanktonic species (A. brigthwellii) are up to four times greater than those of two grazing zooplanktonic species (Daphnia similis and Moina micrura). In this contaminated reservoir that lacks fishes, Asplanchna, and Culex sp. together with ducks and other bigger invertebrates might represent the top predators. Our data suggest that biomagnification of lead through at least one trophic level can occur in freshwater systems. Biomagnification in A. brigthwellii might be explained in part by predation of this voracious predator on young of the herbivorous cladoceran, M. micrura. Our findings stand opposite to the current theoretical framework where lead biomagnification occurs only in lower trophic levels.

Plomo Y Arsénico en La Subcuenca Del Alto Atoyac en Tlaxcala, México

“…El plomo tiene la capacidad de biomagnificarse (García-Hernández et al, 2005;Rubio-Franchini et al, 2008), por lo que su presencia en sedimento, representa un peligro potencial al incorporarse a la cadena trófica. Márquez et al (2008), reportan concentraciones de 0.34 mg·kg -1 de Pb en tejido de peces; en donde el sedimento mostró 22 mg·kg -1 de este metal.…”

“…Lead has the ability to biomagnify (García-Hernández et al, 2005;Rubio-Franchini et al, 2008), so its presence in sediment represents a potential danger of entering the food chain. Márquez et al (2008) reported Pb concentrations of 0.34 mg·kg -1 in fish tissue where the sediment contained 22 mg·kg -1 of this metal.…”

Inter- and Intraspecific Variability in Invertebrate Acute Toxicity Response to Arsenic and Fluoride Exposure

“…For fluoride the sensitivity evaluated thorough 48-h LC 50 , in descending order was: (Rubio-Franchini et al, 2008). Other factors mentioned by Weber (1993) are: a) the age of organisms, b) sensitivity, and c) tested abiotic conditions, quality of dilution water, e.g.…”

Effects of Pollution on Freshwater Organisms

“…Mexico (Rubio-Franchini et al, 2008); the impacts of pesticides on fish harvests from rice fields in the Mekong Delta of Vietnam ( Klemick and Lichtenberg, 2008); the genotoxicity of dredged sediments from the Matanza-Richuelo River in Latin America (Magdaleno et al, 2008); factors affecting macroinvertebrate communities along the Llobregat and Besos River Basins in northeast Spain (Damasio et al, 2008); the toxicity of wastewaters from 17 industries in Portugal's Trancao River Basin ; organotin concentrations in bivalve mussels (Anodonta woodiana) in Taihu Lake in China (Yang et al, 2008c); interactions between trophic and toxic factors in the River Lambro in Italy (Vigano et al, 2008)…”