沉积物是环境演化证据的重要载体,它接收大量来自人为和自然来源的有机物质。在这项研究中,根据沉积年代学,粒度分布的垂直趋势,总有机碳(TOC)总氮(TN),和它们的稳定同位素(δ13C,对大亚湾西南部核电海沉积物岩心中的δ15N)进行了分析,并利用贝叶斯混合模型(MixSIAR)解析了近70年来不同来源有机质在沉积环境中的分布特征和贡献率。TOC,TN,δ13C,和δ15N范围从0.89到1.56%,0.09至0.2%,-22.3至-20.6‰,4.38至6.51‰,分别。沉积物中的有机物由陆地输入和海洋自生的混合物控制,来自陆地来源的有机物的比例增加,虽然来自海洋来源的沉积物芯减少,从1960年到2000年持续存在,但来自海洋来源的有机物仍然占主导地位。初级生产力提高的第一个迹象出现在1960年,这主要是由于农业活动。1980年代以后,大亚湾周围人口的快速增长,核电站的建设,水产养殖的兴起,工业基地的快速扩张都是改变大亚湾生态环境的主要因素。
Sediment is an important carrier of evidence about environmental evolution which receives huge volumes of organic material originated from both anthropogenic and natural sources. In this study, based on sedimentary chronology, the vertical trends of particle size distribution, total organic carbon (TOC), total nitrogen (TN), and their stable isotopes (δ13C, δ15N) in the sediment core of the nuclear power sea in southwest Daya Bay were analyzed, and the distribution characteristics and contribution ratios of different sources of organic matter in the sedimentary environment over the past 70 years were resolved using a Bayesian mixing model (MixSIAR). TOC, TN, δ13C, and δ15N ranged from 0.89 to 1.56%, 0.09 to 0.2%, - 22.3 to - 20.6‰, and 4.38 to 6.51‰, respectively. The organic matter in the sediment is controlled by a mixture of terrestrial input and marine autochthonous, the proportion of organic matter from terrestrial sources increases, while that from marine sources decreases in the sediment core, which persists from 1960 to 2000, yet organic matter from marine sources still dominates. The first signs of increased primary productivity occurred in 1960, and it was primarily due to agricultural activity. After the 1980s, the rapid increase in population around Daya Bay, the construction of nuclear power plants, the rise of aquaculture, and the quick expansion of industrial bases were all major factors that changed the ecological environment of Daya Bay.