Mercury concentration in different tissues of Podocnemis unifilis (Troschel, 1848) (Podocnemididae: Testudines) from the lower Xingu River - Amazonian, Brazil.

J Souza-Araujo,T Giarrizzo,Mo Lima

doi:10.1590/1519-6984.01514bm

J Souza-Araujo, T Giarrizzo + Show 1 more

Open Access

https://doi.org/10.1590/1519-6984.01514bm

Copy DOI

Abstract

Studies using chelonians as biosentinels of environment quality or health risks associated with turtle consumption are very rare, especially in the Amazon basin. This study aims to measure Mercury levels (Hg) in muscle, liver, fat and blood of Podocnemis unifilis from the lower Xingu River, assessing the possible difference in concentration between sexes and also evaluating the potential bioaccumulation along different body sizes. Samples were collected during the dry season (October 2012) and Mercury (Hg) concentrations were analysed by Cold Vapor Atomic Absorption Spectrometry (CVAAS). A total of 29 specimens of P. unifilis of different sizes showed low levels lower than 0.2 mg/Kg). Higher Hg concentrations were found in the liver, and significant correlations between Hg concentrations in the different tissues were also detected. There was no difference between males and females and a negative correlation was found between Hg concentration and body size.

Highlights

The Amazon basin is globally known for Mercury (Hg) contamination found in its soils and rivers (Veiga et al, 1994; Barbosa et al, 1998; Maurice-Bourgoin et al, 2000), and in tissues of organisms, reaching high levels in predatory fish species due to biomagnification (Roulet et al, 2001; Belger and Forsberg, 2006; Kasper et al, 2009, 2012)
This study aims to measure Hg level in muscle, liver, fat and blood of P. unifilis from low Xingu River, assessing the possible difference in concentration between sexes and evaluating potential bioaccumulation in different body sizes of the turtle
Turtles were collected manually with the use of gillnets during the dry season (October 2012), in the lower Xingu river close to Senador José Porfírio municipality (Figure 1) This particular stretch of the Xingu River is known to support an abundant population of turtles during the spawning period, especially species such as the giant Amazon turtle (Podocnemis expansa) (Schweigger, 1812) and Tracajá (Podocnemis unifilis), the latter being the species targeted in this study

Summary

Introduction

The Amazon basin is globally known for Mercury (Hg) contamination found in its soils and rivers (Veiga et al, 1994; Barbosa et al, 1998; Maurice-Bourgoin et al, 2000), and in tissues of organisms, reaching high levels in predatory fish species due to biomagnification (Roulet et al, 2001; Belger and Forsberg, 2006; Kasper et al, 2009, 2012). A major proportion of studies on Hg contamination in the Amazon is focused on fish species from regions with a historical presence of mining activities, installations of hydroelectric dams or in blackwater rivers with acid pH and others favourable conditions for Hg bioavailability (Santos et al, 2000; Dorea, 2003; Oliveira et al, 2010; Vieira et al, 2013).

Objectives

Methods

Results

Conclusion