Department of Physical and Environmental Science, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada M1C 1A4.
Environ Pollut. 2012 Dec;171:207-15. doi: 10.1016/j.envpol.2012.07.043. Epub 2012 Aug 30.
Thousands of hectares of wetlands are created annually because wetlands provide beneficial ecosystem services. Wetlands are also key sites for production of the bioaccumulative neurotoxin methylmercury (MeHg), but little is known about MeHg production in created systems. Here, we studied methylmercury in sediment, water, and invertebrates in created wetlands of various ages. Sediment MeHg reached 8 ng g(-1) in the newest wetland, which was significantly greater than in natural, control wetlands. This trend was mirrored in several invertebrate taxa, whose concentrations reached as high as 1.6 μg g(-1) in the newest wetland, above levels thought to affect reproduction in birds. The MeHg concentrations in created wetland invertebrate taxa generally decreased with increasing wetland age, possibly due to a combination of deeper anoxia and less organic matter accumulation in younger wetlands. A short-term management intervention and/or improved engineering design may be necessary to reduce the mercury-associated risk in newly created wetlands.
由于湿地提供有益的生态系统服务，每年都会有数千公顷的湿地被人工造出来。湿地也是生物蓄积性神经毒素甲基汞（MeHg）的主要产生地，但对于人工湿地系统中 MeHg 的产生情况知之甚少。在这里，我们研究了不同年代的人工湿地中的沉积物、水和无脊椎动物中的甲基汞。最新的湿地中的沉积物甲基汞达到了 8ng/g，明显高于自然对照湿地。这一趋势在几个无脊椎动物类群中得到了反映，其浓度在最新的湿地中高达 1.6μg/g，高于被认为会影响鸟类繁殖的水平。在人工湿地无脊椎动物类群中，甲基汞浓度通常随着湿地年龄的增加而降低，这可能是由于年轻湿地中更深的缺氧和更少的有机物质积累所致。可能需要进行短期的管理干预和/或改进工程设计，以降低新造湿地中与汞有关的风险。
