The presence of mercury in various compartments of aquatic ecosystems is a worrying
problem. The gold mining and mercury occurring naturally in the soil are known as sources
responsible for this contamination. The mercury released into the environment can
accumulate in the tissue of the aquatic animals and concentrations tend to increase as the
animal gains weight and age in a phenomenon known as bioaccumulation. Once in the food
chain biomagnificar mercury, and their concentrations amplified when passing from one
trophic level to another just above. Thus, fish are often used as biological indicators of
environmental contamination. This study aimed to investigate the bioaccumulation and
biomagnification of total mercury in fish associated with aquatic macrophytes in a stretch of
the Amazon River Basin. The collections were made in july and september 2012, six points
located on the Amazon River and its tributaries. The collected fish were identified and had
tissue samples taken for determination of total Hg using the technique of Cold Vapor Atomic
Fluorescence (CVAFS). 50 species were analyzed and only 24% showed patterns of
bioaccumulation of total Hg Just Acestrorhynchus falcirostris (523.6 ± 263.28) species
showed values above the established by legislation with a total significantly higher than the
other species (F 49, 730 = 6.04, p = 0.0000). The piscivorous, insectivorous, and
zooplanctófagas planctófagas species reached higher concentrations in relation to other
trophic levels. The Jurua and Japurá rivers were those with the greatest factors
Biomagnification from producer to primary consumer with values (0.41638 and 0.40912)
respectively. Being the point on the Amazon River near Manacapuru the only one to show
positive Biomagnification. Most species are in total Hg levels below the limits established by
brazilian legislation for human consumption, but some commercial and often consumed
species exceeded the thresholds.
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