Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6359334 | Marine Pollution Bulletin | 2013 | 7 Pages |
Abstract
Total-Hg, monomethylmercury (MMHg), and mercury isotopic composition was determined in sediment from a cold seep and background sites in the northern Gulf of Mexico (nGoM). Total-Hg averaged 50 ng/g (n = 28), ranged from 31 to 67 ng/g, and decreased with depth (0-15 cm). MMHg averaged 0.91 ng/g (n = 18), and ranged from 0.2 to 1.9 ng/g. There was no significant difference for total-Hg or MMHg between cold seep and background sites. δ202Hg ranged from â0.5 to â0.8â° and becomes more negative with depth (r = 0.989). Mass independent fractionation (Î199Hg) was small but consistently positive (0.04-0.12â°); there was no difference between cold seeps (Î199Hg = +0.09 ± 0.03; n = 7, 1SD) and background sites (Î199Hg = +0.07 ± 0.02; n = 5, 1SD). This suggests that releases of hydrocarbons at the cold seep do not significantly alter Hg levels, and that cold seeps are likely not major sources of MMHg to nGoM waters.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Oceanography
Authors
Garry Jr., Kenneth Sleeper, Marcus W. Johnson, Joel D. Blum, James V. Cizdziel,