Influence of dissolved organic matter character on mercury incorporation by planktonic organisms: An experimental study using oligotrophic water from Patagonian lakes

Authors
Dieguez, Maria del Carmen; Queimaliños, Claudia Patricia; Ribeiro Guevara, Sergio; Marvin DiPasquale, Mark; Soto Cárdenas, Estela Carolina; Arribére, María A.
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
Ligands present in dissolved organic matter (DOM) form complexes with inorganic divalent mercury (Hg2+) affecting its bioavailability in pelagic food webs. This investigation addresses the influence of a natural gradient of DOM present in Patagonian lakes on the bioaccumulation of Hg2+ (the prevailing mercury species in the water column of these lakes) by the algae Cryptomonas erosa and the zooplankters Brachionus calyciflorus and Boeckella antiqua. Hg2+ accumulation was studied through laboratory experiments using natural water (NW) of four oligotrophic Patagonian lakes amended with 197Hg2+. The bioavailability of Hg2+ was affected by the concentration and character of DOM. The entrance of Hg2+ into pelagic food webs occurs mostly through passive and active accumulation. The incorporation of Hg2+ by Cryptomonas, up to ~27% of the Hg2+ amended, was found to be rapid and dominated by passive adsorption, and was greatest when low molecular weight compounds (LMW) with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds (HMW) with a humic or fulvic signature kept Hg2+ in the dissolved phase, resulting in the lowest Hg2+ accumulation in this alga. In Brachionus and Boeckella the direct incorporation of Hg from the aqueous phase was up to ~3% of the Hg2+amended. The dietary incorporation of Hg2+ by Boeckella exceeded the direct absorption of this metal in NW, and was remarkably similar to the Hg2+ adsorbed in their prey. Overall, DOM concentration and character affected the adsorption of Hg2+ by algae through competitive binding, while the incorporation of Hg2+ into the zooplankton was dominated by trophic or dietary transfer.
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: Marvin DiPasquale, Mark. United States Geological Survey; Estados Unidos
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
DISSOLVED ORGANIC MATTER
PLANKTON
MERCURY INCORPORATION
PATAGONIAN LAKES
ARGENTINA
Biología Marina, Limnología
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/6715