Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France.
Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France.
Mar Pollut Bull. 2023 Sep;194(Pt B):115439. doi: 10.1016/j.marpolbul.2023.115439. Epub 2023 Aug 26.
Plankton plays a prominent role in the bioaccumulation of mercury (Hg). The MERITE-HIPPOCAMPE campaign was carried out in spring 2019 along a north-south transect including coastal and offshore areas of the Mediterranean Sea. Sampling of sea water and plankton by pumping and nets was carried out in the chlorophyll maximum layer. Two size-fractions of phytoplankton (0.7-2.7 and 2.7-20 μm) and five of zooplankton (between 60 and >2000 μm) were separated, and their total mercury (THg) and monomethylmercury (MMHg) contents were measured. Bioconcentration of THg was significantly higher in the smallest phytoplankton size-fraction dominated by Synechococcus spp. The bioaccumulation and biomagnification of MMHg in zooplankton was influenced by size, food sources, biochemical composition and trophic level. MMHg was biomagnified in the plankton food web, while THg decreased toward higher trophic levels. Higher MMHg concentrations were measured in oligotrophic areas. Plankton communities in the Southern Mediterranean Sea had lower MMHg concentrations than those in the Northern Mediterranean Sea. These results highlighted the influence of environmental conditions and trophodynamics on the transfer of Hg in Mediterranean plankton food webs, with implications for higher trophic level consumers.
浮游生物在汞（Hg）的生物积累中起着重要作用。MERITE-HIPPOCAMPE 项目于 2019 年春季进行，沿地中海的一条南北向断面进行，包括沿海和近海地区。通过泵和网在叶绿素最大值层中抽取海水和浮游生物样本。分离出浮游植物的两个大小分数（0.7-2.7 和 2.7-20 μm）和浮游动物的五个大小分数（60 至>2000 μm），并测量其总汞（THg）和单甲基汞（MMHg）含量。由 Synechococcus spp 主导的最小浮游植物大小分数的 THg 生物浓缩率明显更高。MMHg 在浮游动物中的生物积累和生物放大受大小、食物来源、生化组成和营养水平的影响。MMHg 在浮游生物食物网中被生物放大，而 THg 在较高营养水平上减少。在贫营养区测量到更高的 MMHg 浓度。与地中海北部相比，南地中海的浮游生物群落的 MMHg 浓度较低。这些结果强调了环境条件和营养动态对地中海浮游生物食物网中 Hg 转移的影响，对更高营养水平的消费者有影响。
