File Entry: CUANTIFICACIÓN DE LAS CONCENTRACIONES DE METALES PESADOS EN TEJIDOS DE PECES Y CRUSTÁCEOS DE LA LAGUNA DE UNARE, ESTADO ANZOÁTEGUI, VENEZUELA.

The content of Fe, Mn, Cu, Cr, Ni, Zn, Cd and Pb in muscle tissues
of fish and crustaceans from the Unare lagoon (Laguna
de Unare) in the state of Anzoátegui, Venezuela, was analyzed
by flame Atomic Absorption Spectrometry. The levels of these
metals present in suspended material of the water and in sediments
were also determined in order to detect possible impact
on the ecosystem. The mean concentrations in the water were
low (0.104-0.53 μmol/L Fe; 0.004-0.06 μmol/L Mn; 0.002-0.028
μmol/L Zn; 0.004-0.012 μmol/L Cr; undetectable-0.011 μmol/L
Ni and undectable-0.001 μmol/L Cd). In the sediments, evidence
was found of anthropogenic intervention with mean values
in decreasing order of Mn (516.37) > Zn (127.49) > Ni
(52.41) > Cr (51.69) > Cu (41.13) > Pb (29) > Cd (1.51 μg/g),
all of which are greater than established levels for uncontaminated
sediments. Toxic metals were detected in the examined
organisms, such as lead and cadmium with levels above 0.16
and 0.04 μg/g, respectively, and zinc with levels greater than
17 μg/g in the majority of the species. ANOVA statistical tests
(P < 0.05) show discrepancies in the concentrations or the
metals in the tissues of the different genera and species, as
well as in the values for individuals of the same species
(Cathorops spixii) which live inside and outside of the lagoon.
The levels are higher in those which live within the lagoon, 
which indicates bioaccumulation processes. This study confirms
that the lagoon and its biota have suffered a progressive
and important deterioration inasmuch as the neighboring population
relies on the commercialization of the fish and crustaceans
for their economic stability.