Effect of Aquatic Organic Matter and Global Warming on Accumulation of PAHs in Lakes, East China

Abstract

Abstract The sedimentary records of organic matter in lakes can reflect the response of lakes to global warming. Multiple organic proxies in the sediment core samples collected from Luoma Lake and Hongze Lake in Jiangsu were used to expound the effects of global warming and anthropogenic activities on lacustrine productivity and deposition of polycyclic aromatic hydrocarbons (PAHs). Total organic carbon, algal organic matter proxies (S2 and hydrogen index), and nutrients such as total phosphorus and total nitrogen were measured. The source apportionment modeling and the principal component analysis demonstrated that algal organic matter and bacteria organic matter showed an upcore increasing trend and an obvious enrichment effect on PAHs, which was also related to the increasing temperature and algal productivity in the lakes. Global warming enhanced the lacustrine productivity and the accumulation of PAHs in sediments. Therefore, the organic geochemical indicators in lake sediments can effectively reflect the impact of climate warming on the lacustrine productivity and the accumulation of PAHs, and provide data support for the management of lakes.