为了反演珠江口过去环境的厌氧氨氧化活动状况,本文分析了来自珠江口3个站位的柱状沉积物中梯烷脂的含量,在所有的样品中均检测到了梯烷脂,表明珠江口地区存在厌氧氨氧化活动。P03沉积柱的梯烷脂总含量为0.16~4.13μg/g,L1为0.15~1.3μg/g,C2T为0.07~2.19μg/g。梯烷脂的垂直分布特征表明3个沉积柱中厌氧氨氧化细菌的来源可能不同,P03沉积柱中梯烷脂可能主要来源于沉积物中的厌氧氨氧化细菌,而L1梯烷脂可能来自上层水体和沉积物,C2T的厌氧氨氧化活动可能主要发生在底层缺氧水体中。将梯烷脂与总有机碳(TOC)作相关性分析,结果显示在TOC含量高的柱状样中,两者相关性好,TOC校准后的梯烷脂与原梯烷脂的分布趋势的一致性,表明梯烷脂含量能够指示厌氧氨氧化活动。对珠江口过去的厌氧氨氧化活动的重建表明P03站位沉积物中厌氧氨氧化活动自1970-1990增强,L1站位的厌氧氨氧化活动近十年来亦逐年增强,C2T站位上覆水体的厌氧氨氧化活动则呈现近几年快速增强的趋势。虽然本研究仅初步探讨了近些年来珠江口厌氧氨氧化活动的变化规律,但为进一步研究珠江口氮循环过程提供了良好的基础。
In order to reveal the past anammox of the Pearl River Estuary we analyzed the ladderane core lipids content of three sediment cores from the Pearl River Estuary, and all ladderane core lipids have been detected in almost all investigated sedimentary samples, suggesting the presence of anammox activity in the Pearl River Estuary. The summed content of ladderane core lipids at site P03,L1 and C2T was 0. 16 to 4. 13μg/g, 0. 15 to 1.3μg/g and 0. 07 to 2. 19μg/g respectively. The vertical distribution of ladderane lipids indicated that the source of anammox bacteria may be different in the three sediments cores. Ladderane lipids at site P03 were possible mainly produced by the anammox bacteria of the sediment itself, but at site L1 they maybe come from both the sediment itself and the settling of the above water column, and at site C2T the anammox process may only occur in the anoxia bottom water. The correlation analysis between the content of total organic carbon and the summed ladderane core lipids found that the high abundance of TOC has better correlation, and the same distribution of the ladderane lipids normalized by TOC and the original ladderane lipids shown that the content of ladderane lipids could indicate anammox. The reconstruct of past anammox in the Pear River Estuary revealed that the anammox activity of sediment cores at site P03 had a slowly increasing trend in 1970s~1990s and at site L1 it had a similar trend over the last decade, but at site C2T the anammox activity of bottom water showed a rapid increase in recent years. Although we only preliminary discussed how the anammox in the Pearl River Estuary have changed for years, we also offer a well theory basis for the further study about the nitrogen cycle of the Pearl River Estuary