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

作     者：María C.Diéguez Claudia P.Queimalios Sergio Ribeiro Guevara Mark Marvin-DiPasquale Carolina Soto Crdenas María A.Arribre 

作者机构：Laboratorio de Fotobiología INIBIOMA CONICET-UNComahue Laboratorio de Fotobiolog INIBIOMA CONICET-UNComahue Laboratorio de Anlisis por Activación Neutrónica Centro Atómico Bariloche CNEA United States Geological Survey Laboratorio de Anlisis por Activacio Neutrónica Centro Atómico Bariloche CNEA 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2013年第25卷第10期

页      面：1980-1991页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学] 

基　　金：funded by Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT PICT 200700393) Consejo Nacional de Investigaciones Científicas y Tcnicas(CONICET PIP 11220100100064) International Atomic Energy Agency(IAEA TCP ARG7007) Universidad Nacional del Comahue(Program 04-B166) 

主　　题：mercury dissolved organic matter plankton mercury incorporation Patagonian lakes Argentina 

摘      要：Ligands present in dissolved organic matter （DOM） form complexes with inorganic divalent mercury （Hg^2＋） 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 Hg^2＋ （the prevailing mercury species in the water column of these lakes） by the algae Cryptomonas erosa and the zooplankters Brachionus calyciflorus and Boeckella antiqua. Hg^2＋ accumulation was studied through laboratory experiments using natural water of four oligotrophic Patagonian lakes amended with^197Hg^2＋. The bioavailability of Hg^2＋ was affected by the concentration and character of DOM. The entrance of Hg^2＋ into pelagic food webs occurs mostly through passive and active accumulation. The incorporation of Hg^2＋ by Cryptomonas, up to 27% of the Hg^2＋ amended, was found to be rapid and dominated by passive adsorption, and was greatest when low molecular weight compounds with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds with a humic or fulvic signature kept Hg^2＋ in the dissolved phase, resulting in the lowest Hg^2＋ accumulation in this algae. In Brachionus and Boeckella the direct incorporation of Hg from the aqueous phase was up to 3% of the Hg^2＋ amended. The dietary incorporation of Hg^2＋ by Boeckella exceeded the direct absorption of this metal in natural water, and was remarkably similar to the Hg^2＋ adsorbed in their prey. Overall, DOM concentration and character affected the adsorption of Hg^2＋ by algae through competitive binding, while the incorporation of Hg^2＋ into the zooplankton was dominated by trophic or dietary transfer.