Uptake of Hg2+ by picocyanobacteria in natural water from four Andean lakes

Authors
Dieguez, Maria del Carmen; Queimaliños, Claudia Patricia; Ribeiro Guevara, Sergio; DiPasquale, Mark Marvin; Gerea, Marina; Soto Cárdenas, Estela Carolina; Arribére, María A.
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
In lake food webs, planktonic bacteria and algae represent the greatest bioconcentration step for Hg2+ and monomethyl-Hg (MeHg). As they are the most abundant organisms in planktonic trophic webs and also the main food resource for herbivorous plankton, they can mobilize large amounts of Hg to higher trophic levels. In Andean Patagonian lakes (Argentina), Dissolved organic matter (DOM) concentration and character, coupled with photo-reactions, play a central role in the complexation of Hg2+ in the water column and can even regulate the uptake of Hg2+ by planktonic algae. In this investigation we evaluated the DOM character of natural waters (NW) from four Andean lakes and studied its influence on the uptake of 197Hg2+ in a strain of the picocyanobacteria Synechococcus by using Hg2+ labeled with 197Hg2+. The uptake of radiolabeled Hg2+ by Synechococcus showed different magnitude in NW of lakes Moreno, El Trébol, Morenito and Escondido. Increasing lake DOM concentration reduced the bioavailability of Hg2+ as indicated by the lower uptakes rates found in NW with higher complexity and concentration of the DOM pool. Uptakes of Hg2+ by this picocyanobacteria contrasted among NW from pelagic (surface and bottom) and littoral compartments of Lake Escondido which suggest that the entry of this metal may be highly variable even in the same environment. The study of the uptake of radiolabeled Hg2+ in a set of dilutions of NW from Lake Escondido demonstrated that the bioavailability of Hg2+ decrease with increasing DOM concentration.
Fil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina
Fil: Queimaliños, Claudia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina
Fil: Ribeiro Guevara, Sergio. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Unidad de Actividad de Ingenieria Nuclear. Laboratorio de Analisis Por Activacion Neutronica; Argentina
Fil: DiPasquale, Mark Marvin. United States Geological Survey; Estados Unidos
Fil: Gerea, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina
Fil: Soto Cárdenas, Estela Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina
Fil: Arribére, María A.. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Unidad de Actividad de Ingenieria Nuclear. Laboratorio de Analisis Por Activacion Neutronica; Argentina
Subject
MERCURY
BIOACCUMULATION
PICOCYANOBACTERIA
NATURAL WATER
ANDEAN-PATAGONIAN LAKES
Oceanografía, Hidrología, Recursos Hídricos
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Open access
License
https://creativecommons.org/licenses/by/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/6812