九龙江口-厦门湾海域中溶解态痕量金属的时空分布特征与影响机制

Spatial and Temporal Distribution and Influencing Factors of Dissolved Trace Metals in Jiulong River Estuary and Xiamen Bay

痕量金属在海洋系统的一些生物地球化学过程中发挥着重要作用,河口及近岸海域物理水文条件变化复杂,且受人为活动影响显著,因此近海海域中痕量金属的生地化行为与影响机制是研究的热点.九龙江口-厦门湾海域位于福建沿海地区,受龙岩、厦门和漳州等城市影响较为显著.分别于2021年7月、 2021年11月和2022年1月对九龙江口-厦门湾海域的痕量金属铬(Cr)、锰(Mn)、钴(Co)、镍(Ni)、铜(Cu)、镉(Cd)和环境因子[水温、盐度、 pH、溶解氧(DO)和悬浮颗粒物(SPM)等]进行了3个航次的调查.结果表明,九龙江口-厦门湾流域所测痕量金属浓度平均值大小顺序:Mn>Ni>Cu>Cr>Co>Cd.ρ(Cr)、ρ(Mn)、ρ(Co)、ρ(Ni)、ρ(Cu)和ρ(Cd)在2021年7月的平均值分别为:0.159、 47.96、 0.068、 1.56、 1.07和0.016μg·L^(-1);2021年11月的平均值分别为:0.216、 8.48、 0.030、 1.70、 1.92和0.019μg·L^(-1);2022年1月平均值分别为:0.281、 32.39、 0.062、 2.21、 1.54和0.034μg·L^(-1).河口区溶解态痕量金属浓度高于海湾区.主成分分析表明,影响溶解态痕量金属浓度的主要因素为河口径流和人类活动.

Trace metals play an important role in some biogeochemical processes in the marine system. The physical and hydrological conditions in estuaries and coastal seawater are complicated and significantly affected by human activities. Therefore, the biogeochemical behavior and influencing mechanism of trace metals in nearshore water have become a research hotspot. Jiulong River estuary and Xiamen Bay are located in the coastal areas of Fujian Province, which are significantly influenced by Longyan, Xiamen, and Zhangzhou City. In July 2021, November 2021, and January 2022, the trace metals chromium(Cr), manganese(Mn), cobalt(Co), nickel(Ni), copper(Cu), and cadmium(Cd) and environmental factors(water temperature, salinity, pH, dissolved oxygen(DO), suspended particulate matter(SPM), etc.) in Jiulong River estuary and Xiamen Bay were investigated. The results showed that the order of trace metal concentration average values measured in Jiulong River estuary and Xiamen Bay was Mn>Ni>Cu>Cr>Co>Cd. In July 2021, the average values of ρ(Cr), ρ(Mn), ρ(Co), ρ(Ni), ρ(Cu), and ρ(Cd) were 0.159, 47.96, 0.068, 1.56, 1.07, and 0.016 μg·L^(-1), respectively. In November 2021, the average values were 0.216, 8.48, 0.030, 1.70, 1.92, and 0.019 μg·L^(-1), respectively. The average concentrations in January 2022 were 0.281, 32.39, 0.062, 2.21, 1.54, and 0.034 μg·L^(-1), respectively. The concentration of dissolved metals in the estuary was higher than that in the bay area. Principal component analysis showed that the main factors affecting the concentrations of dissolved trace metals were river runoff and anthropogenic activities.