Ecotoxicologia do mercúrio total em poríferos do Hidrossistema Fluvial Baixo Tapajós, Santarém - Pará, Brasil.
Fecha
2018-06-08Autor
http://lattes.cnpq.br/2433725805176733
EUFRÁZIO, Francisco Lutiano Paiva
Metadatos
Mostrar el registro completo del ítemResumen
Concentrations of total mercury (HgT) in freshwater poriferous in Brazil were recorded
for the first time. Concentrations of HgT were analyzed in poriferous of the Tapajós low
hydrosystem from the mouth upstream in 65 kilometers stretch on the right bank of the river,
relating them to spatial, environmental and limnological factors. The collections occurred in 12
river regions and seven lacustrine regions in the Tapajós river, in the municipality of Santarém Pará, between the high water period and the beginning of the ebb of 2017. This work increased
the number of freshwater poriferous species for the Tapajós river, from 16 to 20, with the
increment of four new records: Drulia ctenosclera, Saturnospongilla carvalhoi, Tubella
lanzamirandai and Metania reticulata. The mean concentration of HgT in the poriferous in the
studied section of the Tapajós River was 40.8±3.9 ng.g.-1
, being higher in the lacustrine
environment (40.6±23.4 ng.g.-1
) than those in the fluvial environment (28.1±29.2 ng.g.-1
).
Regardless of the environment, mean concentrations of HgT were more significant in the
Carapanarí region (70.0±24.1 ng.g.-1
). When analyzing body mass, the Reproductive Tissue
presented the highest concentrations of HgT (56.4±11.1 ng.g.-1
). In Drulia uruguayensis, the
concentrations of HgT in the Inner Vegetative Tissue were directly proportional to the vertical
distribution in the water column, that is, the increase of the colonization depth of the species in
the water column explained 43% of the source of variation of HgT between (r= 0.4271, p=
0.0038), whereas Drulia brownii showed a negative correlation with pH (r= -0.55, p= 0.042),
Silica (r= -0.58, p= 0.028) and Potassium (r= -0.76, p= 0.001) in the Reproductive Tissue and
with Sodium (r= -0.55, p= 0.033) in the Internal Vegetative Tissue. D. uruguayensis and D.
brownii were the species with the highest occurrence (52.8%), being sampled in most regions
and environments. The variations in HgT concentrations in the trophic levels are directly related
to the alimentary habit of each organism. In the case of poriferous, concentrations of HgT were
considered low when compared to the concentrations in other aquatic organisms, however, due
to their sessility and filtering habit, they may reflect the specific situation of each environment,
being proposed as biomonitors of environmental pollution.