Laboratory of Hydrobiology, Institute of Biomedical Sciences-ICBAS-UP, University of Porto, Rua de Jorge Viterbo Ferreira, No. 228, 4050-313 Porto, Portugal.
Mar Pollut Bull. 2013 Jan 15;66(1-2):225-9. doi: 10.1016/j.marpolbul.2012.11.004. Epub 2012 Dec 6.
We investigated the influence of salinity on sediment inorganic nitrogen dynamics in three Portuguese estuaries (Cávado, Ave and Douro). Anaerobic slurry experiments were run at different salinity treatments (0, 10, and 25) and net changes in concentration of nitrate, nitrite, ammonium, and nitrous oxide were monitored. Salinity-induced NH₄⁺ sediment desorption was observed at all sites. No significant salinity driven changes in NO₃⁻ concentrations were observed, except for Ave estuarine sediments, where NO₃⁻ consumption increased 10 times as the salinity rose from 0 to 10. In the upper stretches of the three estuaries, N₂O production increased sharply as salinity rose. Although no stimulation of N₂O production was observed in higher salinity areas, the salinity-driven changes in N₂O production are of major concern given the greenhouse characteristics of the gas. The global trend of decreasing freshwater discharge, and therefore increase in salinity, to estuarine systems could thereby exacerbate N₂O production and global warming.
我们研究了盐度对葡萄牙三个河口（卡瓦多、阿夫雷罗和杜罗）沉积物无机氮动态的影响。在不同盐度处理（0、10 和 25）下进行了厌氧泥浆实验，并监测了硝酸盐、亚硝酸盐、铵和氧化亚氮浓度的净变化。在所有地点都观察到盐度诱导的 NH₄⁺沉积物解吸。除了阿夫雷罗河口沉积物外，没有观察到 NO₃⁻浓度随盐度显著变化，在盐度从 0 升高到 10 时，NO₃⁻消耗增加了 10 倍。在三个河口的上游，随着盐度的升高，N₂O 的产生急剧增加。尽管在较高盐度区域没有观察到 N₂O 产生的刺激，但鉴于该气体的温室特征，盐度驱动的 N₂O 产生变化值得关注。全球淡水排放量减少，从而导致河口系统盐度增加，这可能会加剧 N₂O 的产生和全球变暖。
