Pouilly Marc, Pérez T., Rejas D., Guzman F., Crespo G., Duprey Jean-Louis, Guimaraes J. R. D. (2012). Mercury bioaccumulation patterns in fish from the Itenez river basin, Bolivian Amazon. Ecotoxicology and Environmental Safety, 83, p. 8-15. ISSN 0147-6513.
Titre du document
Mercury bioaccumulation patterns in fish from the Itenez river basin, Bolivian Amazon
Pouilly Marc, Pérez T., Rejas D., Guzman F., Crespo G., Duprey Jean-Louis, Guimaraes J. R. D.
Source
Ecotoxicology and Environmental Safety, 2012,
83, p. 8-15 ISSN 0147-6513
The bioaccumulation mechanism expresses an increment of mercury concentration along the lifetime of each individual. It is generally investigated along the age or size range of organisms from a same population. Water chemistry and trophic position are important factors that may influence the emergence of bioaccumulation patterns. In order to detect the influence of these parameters on fish mercury bioaccumulation patterns, we explored the relations between mercury concentration, size and isotopic trophic position of fish populations of six species (three non piscivorous and three piscivorous) in three rivers of the Itenez basin (Bolivia) with different sediment load in water and anthropogenic impact. Fishes of the Itenez basin showed fairly lower mercury contamination in relation to the regional context. They presented lower total mercury concentrations in unperturbed clear water river (average of 0.051 mu g g(-1) for non piscivores; 0.088 mu g g(-1) for piscivores), intermediate values (average of 0.05 and 0.104 mu g g(-1)) in unperturbed white water river, whereas the highest values (average of 0.062 and 0.194 mu g g(-1)) were found in the perturbed clear water river. Piscivore and invertivore species showed significant positive bioaccumulation patterns in the perturbed river and in the unperturbed white water river. No positive pattern was detected in the unperturbed clear water river. Positive patterns could not be attributed to differences in trophic condition and mean fish mercury concentration between populations. Bioaccumulation seems not to be the main factor to explain increased mercury concentrations in fish from the perturbed river.
