Department of Biology, Queen's University, Kingston, Ontario, Canada.
Environ Toxicol Chem. 2013 Apr;32(4):857-65. doi: 10.1002/etc.2118. Epub 2013 Feb 21.
Ebullition, the release of gas from anaerobic decomposition in sediments, was recorded in a mercury-contaminated depositional zone (Zone 1) of the St. Lawrence River Area of Concern in Cornwall, Ontario, Canada. The aim of the present study was to test if this disturbance affected the bioavailability of total mercury (THg) and methylmercury (MeHg) in surficial sediments to a benthic invertebrate (Echinogammarus ischnus). Ebullition rates ranged from <1 to 2,800 ml/m(2) daily, with methane gas comprising 29 to 84% of the total. No direct effects of ebullition were found on either abiotic (sediment or pore water THg or MeHg concentrations) or biotic (amphipod THg or MeHg concentrations) variables measured. Instead, amphipod MeHg concentrations were best predicted by pore water THg and MeHg concentrations, organic matter of surficial sediments, and water depth and location. Trend surface analyses demonstrated that a shallow, southwestern part of Zone 1 was most contaminated with pore water mercury, which decreased in a gradient toward the northeast. Further study is needed to determine if the amount of sediment resuspended by ebullition affects the spatial distribution of mercury.
在加拿大安大略省康沃尔的圣劳伦斯河关注区域的一个汞污染沉积区（第 1 区）中，记录到了由于厌氧分解而从沉积物中释放气体的沸腾现象。本研究的目的是测试这种干扰是否会影响底栖无脊椎动物（Echinogammarus ischnus）表层沉积物中总汞（THg）和甲基汞（MeHg）的生物利用度。沸腾速率每天从<1 到 2800ml/m(2)不等，其中甲烷气体占总气体的 29%至 84%。沸腾没有直接影响到测量的非生物（沉积物或孔隙水 THg 或 MeHg 浓度）或生物（甲壳类动物 THg 或 MeHg 浓度）变量。相反，甲壳类动物 MeHg 浓度与孔隙水 THg 和 MeHg 浓度、表层沉积物中的有机质以及水深和位置呈最佳相关性。趋势面分析表明，第 1 区较浅的西南部分受到的孔隙水汞污染最严重，从西南向东北逐渐减少。需要进一步研究来确定沸腾引起的沉积物再悬浮量是否会影响汞的空间分布。
