thumbnail

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

Journal of Environmental Sciences

By:
, , , , , and
DOI: 10.1016/S1001-0742(12)60281-2

Links

Abstract

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 of four oligotrophic Patagonian lakes amended with197Hg2+. 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 with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds with a humic or fulvic signature kept Hg2+ in the dissolved phase, resulting in the lowest Hg2+ accumulation in this algae. 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 natural water, 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.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Influence of dissolved organic matter character on mercury incorporation by planktonic organisms: an experimental study using oligotrophic water from Patagonian lakes
Series title:
Journal of Environmental Sciences
DOI:
10.1016/S1001-0742(12)60281-2
Volume
25
Issue:
10
Year Published:
2013
Language:
English
Publisher:
Elsevier
Contributing office(s):
National Research Program - Western Branch
Description:
11 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Environmental Sciences
First page:
1980
Last page:
1991
Number of Pages:
11
Country:
Argentina
Other Geospatial:
Patagonia