AMAZON KINGFISHER (CHLOROCERYLE AMAZON) AS POTENTIAL SENTINEL SPECIES FOR HG POLLUTION IN BRAZILIAN AMAZONIA AND PANTANAL

The objective of this work was to evaluate the Hg levels in target organs \nof one species of kingfisher, Chloroceryle amazona, in three South \nAmerican rivers in Brazilian Amazonia and Pantanal. We determined Hg \nin liver, muscle and feathers, in relation to size, weight and age of the \nbirds, and Hg in the river water, and in relation to the deforestation dynamics \nof the areas, reconstructed in a time series of 40 years. The highest \nHg were measured in the suspended particulate (8.6 ± 3.7 ng/L) and \nfiltered portions (0.9 ± 0.4 ng/L) of the Teles Pires River in comparison \nwith Juruena River (4.1 ± 3.6 and 0.8 ± 0.2 ng/L, respectively). The highest \nHg among tissues was in the following order: feathers (4.97 ± 0.86 \nng/L) > liver (0.80 ± 0.018 ng/L) > muscle (0.41 ± 0.11 ng/L). The highest \nlevels in the feathers and muscle were found in the Teles Pires River \nsamples (F=7.78, p=0.03; F=17.16, p=0.01 respectively). On the other \nhand, liver showed the highest Hg concentration in the samples of the \nJuruena River (F=3.83; p = 0.04). There is a significant correlation between \nTHg concentrations in feathers and muscle (R²=0.76, p=0.01) in \nboth rivers. Likewise, we found a significant positive correlation between \nthe animal’s length and Hg concentrations in liver (R²= 0.10, p=0.04) and \nfeathers (R²= 0.13; p=0.02). The satellite images showed severe changes \nin the landscape, with the withdrawal of native vegetation for agriculture \nor livestock. Considering the total area of buffers, created within the \ncollection area in each river, the Teles Pires River (cerrado-Amazonian \ntransition area) lost about 25% of its original coverage, whereas the Juruena \nriver (Amazon forest) lost is 18% and the Paraguay (cerrado) / humid \nzone / shrub vegetation) around 35.92%, between the years of 1988- \n2018. Our results suggest C. amazona as a potential sentinel species \nfor the monitoring of environmental Hg contamination in Amazonia and \nPantanal. In addition, our data point to a possible relationship between \ndeforestation and Hg values in river water and biota.