Resumen

MARQUEZ, Aristide et al. Metals Concentration in Sediments and Muscular Tissues of Some Fish from the Castillero Lagoon, Venezuela.. Rev. Cient. (Maracaibo) [online]. 2008, vol.18, n.2, pp.121-133. ISSN 0798-2259.

To detected alterations in the productive ecosystem of the Castillero Lagoon (Caicara of the Orinoco, Cedeño Municipality, Bolivar State, Venezuela), results are presented for granulometric measurements and heavy metals concentrations: Fe, Mn, Zn, Pb and Co made in June 2001 on superface sediments and of the muscular tissue of several native species of fish (Plasgiosium squamossimos, Pigocentrus cariba, Pheudoplastyloma fasciatum, and Hypostomus spp. By using atomic absorption spectrophotometry with an air-acetylene flame, it was determined that the highest concentrations of metals are represented by manganese, zinc and lead. It was determined that the highest concentrations of metals are represented by manganese, zinc and lead. In the most internal part in the lagoon the type of predominant sediments is the mud, constituting among 30% and 65% of the material collected by station. Is that those levels fall toward the mouth of the lagoon, product of the interaction of the flow / reflux currents that washes the sediment and that is reflected in the biggest presence of fine sand. The statistical analysis of ANOVA shows significant differences among the concentrations of the metals in the stations, tipificated for the presence of different averages. The averages levels for the superficial sediments of the area are the following ones: Fe (3365.44 ± 261.61), Mn (132.17 ± 25.46), Zn (253.04 ± 86.48), Pb (17.02 ± 2.21) y Co (4.65 ± 0.76) µg/g. In similarly way, in the muscular tissue of the fish the following concentrations were quantified: Fe between (31.26 ± 0.06) and (68.36 ± 0.05); Mn between (2.02 ± 0.05) and (4.16 ± 0.03); Zn between (19.09 ± 0.01) and (28.89 ± 0.01); Pb between (0.38 ± 0.01) and (0.47 ± 0.03) µg/g. The analysis reflects a remarkable association between the high securities of concentrations of metals and the sediments type, with a growing gradient toward the sediments type mud. These are alarming values in concentration of Pb and Zn, attributed to the stress that produces the anthropogenic activities surrounding the Lagoon of Castillero. It can be concluded that based on the diagnosis that the ecosystem of the lagoon is in evident state of deterioration with implications that could affect the species inhabit, and the economic activities of the population that exploit the resources biotiques of that body of water.

Palabras clave : Heavy metals; sediments; fish; pollution; flood lagoon.