Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China; Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Guangzhou, 510632, China.
Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region.
Water Res. 2020 Mar 1;170:115302. doi: 10.1016/j.watres.2019.115302. Epub 2019 Nov 12.
Biological pump is important to control the fate and distribution of organic contaminants, particularly in temperate and cold oligotrophic waters. However, it remains largely unknown how factors affect the long-term occurrence and fate of ionogenic organic compounds in subtropical eutrophic waters. The present study aimed to assess biogeochemical and physical factors affecting the annual occurrence, bioaccumulation, and trophic transfer of 14 antibiotics through planktonic food webs in the Pearl River, a large subtropical eutrophic river in China. This was done by carrying out 1-year simultaneous field observations of antibiotic concentrations in five water column compartments and assessing the variability of bioconcentration (BCF), bioaccumulation (BAF), and biomagnification (BMF) factors, which were influenced by plankton biomass, pH and temperature of water columns. The annual mean antibiotic concentration per site ranged from 1014.66 ± 535.66 ng L to 1464.63 ± 1075.91 ng L, and was positively correlated with phytoplankton biomass, but independent of the proximity of the sites to urban areas. Antibiotic occurrences in both phytoplankton and zooplankton were greatly influenced by a biodilution effect. The annual occurrence of antibiotics in the water column was modulated by biological pumps as well as their equilibrium partitioning, and indirectly influenced of eutrophication with pH increased with phytoplankton biomass and phytoplankton life cycling. BAF of antibiotics by plankton had biphasic correlations with temperature (n = 150, R = 0.17-0.60, p < 0.001) and decreased with plankton biomass (n = 105-147, R = 0.10-0.22, p < 0.001). The trophic transfer of antibiotics from phytoplankton to zooplankton (BMFs) were positively correlated with both phytoplankton biomass (n = 30, R = 0.58, p < 0.001) and temperature (n = 132-150, R = 0.12-0.43, p < 0.001). Mean BMFs of ciprofloxacin, lomefloxacin, ofloxacin, oxytetracycline, and tetracycline ranged between 0.18 and 2.25, implying these chemicals can undergo biomagnification along planktonic food webs. The present research demonstrates the important role of biogeochemical and physical factors in the environmental fate of antibiotics at large spatiotemporal scales.
生物泵对于控制有机污染物的归宿和分布非常重要，尤其是在温带和寒冷贫营养的水域中。然而，在亚热带富营养水域中，有哪些因素会影响离子型有机化合物的长期存在和归宿，目前我们仍知之甚少。本研究旨在评估生物地球化学和物理因素如何影响通过珠江浮游食物网中抗生素在年际水平上的发生、生物蓄积和营养转移。珠江是中国一条大型亚热带富营养河流。本研究通过对 5 个水柱隔室中抗生素浓度进行为期 1 年的同步现场观测，并评估生物浓缩（BCF）、生物蓄积（BAF）和生物放大（BMF）因子的变异性，这些因子受到浮游生物生物量、水柱 pH 值和温度的影响，从而实现了这一目标。每个站位的年平均抗生素浓度范围为 1014.66 ± 535.66ng/L 至 1464.63 ± 1075.91ng/L，与浮游植物生物量呈正相关，但与站位与城市的距离无关。浮游植物和浮游动物中抗生素的存在受到生物稀释效应的极大影响。水柱中抗生素的年发生情况受生物泵以及其平衡分配的调节，并间接受到富营养化的影响，随着浮游植物生物量的增加和浮游植物生命周期的进行，pH 值也随之升高。浮游生物对抗生素的 BAF 与温度呈双相相关（n=150，R=0.17-0.60，p<0.001），并随浮游生物生物量减少（n=105-147，R=0.10-0.22，p<0.001）。抗生素从浮游植物到浮游动物的营养转移（BMFs）与浮游植物生物量（n=30，R=0.58，p<0.001）和温度（n=132-150，R=0.12-0.43，p<0.001）呈正相关。环丙沙星、洛美沙星、氧氟沙星、土霉素和四环素的平均 BMF 值介于 0.18 和 2.25 之间，这表明这些化学物质可以在浮游食物网中发生生物放大。本研究表明，生物地球化学和物理因素在抗生素在大时空尺度上的环境归宿中起着重要作用。
