Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia, Universidade Estadual Do Norte Fluminense Darcy Ribeiro, Parque Califórnia, CEP, Campos Dos Goytacazes, Rio de Janeiro, RJ, 28013-602, Brazil.
Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia, Universidade Estadual Do Norte Fluminense Darcy Ribeiro, Parque Califórnia, CEP, Campos Dos Goytacazes, Rio de Janeiro, RJ, 28013-602, Brazil.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111249. doi: 10.1016/j.ecoenv.2020.111249. Epub 2020 Sep 2.
Mercury (Hg) biomagnification in fish food chains is a relevant subject due to the high fish consumption of the Amazonian population and the high toxicity of this metal. In the Amazon, floodplain lake hydrodynamics change considerably along the four seasons of the hydrological cycle (rising water, high water, falling water and low water), which can influence Hg bioaccumulation in fish. The main aim of this study was to evaluate if Hg biomagnification is influenced by seasonality in a floodplain lake (Puruzinho Lake) in the Brazilian Amazon. Additionally, the influence of food chain modeling on measurement of Hg biomagnification was tested. Hg concentrations and stable isotope signatures (carbon and nitrogen) were estimated in four species, Mylossoma duriventre (herbivorous), Prochilodus nigricans (detritivorous), Cichla pleiozona (piscivorous) and Serrasalmus rhombeus (piscivorous). The "trophic magnification slope" (TMS) of the food chain composed by the four species was calculated and compared among the four seasons. There was no significant seasonal variation in TMS among rising water, high water, falling water and low water seasons (p = 0.08), suggesting that Hg biomagnification does not change seasonally. However, there was significant variation in TMS among different food chain models. Lower TMS was observed in a food chain composed of detritivorous and piscivorous fish (0.20) in comparison with a food chain composed of the four species (0.26). The results indicate food chain modeling influences TMS results.
汞（Hg）在鱼类食物链中的生物放大是一个相关的主题，这是由于亚马逊地区人口对鱼类的高消耗以及该金属的高毒性。在亚马逊地区，洪泛区湖泊的水动力在水文循环的四季（涨水期、高水位期、退水期和枯水期）中发生了很大的变化，这可能会影响鱼类体内的汞生物积累。本研究的主要目的是评估在一个洪泛区湖泊（普鲁津霍湖）中，汞的生物放大是否受到季节性的影响。此外，还测试了食物链建模对测量汞生物放大的影响。在四个物种中估计了汞浓度和稳定同位素特征（碳和氮），这四个物种分别为：Mylossoma duriventre（草食性）、Prochilodus nigricans（碎屑食性）、Cichla pleiozona（肉食性）和 Serrasalmus rhombeus（肉食性）。计算了由这四个物种组成的食物链的“营养放大斜率”（TMS），并在四个季节之间进行了比较。在涨水期、高水位期、退水期和枯水期之间，TMS 没有明显的季节性变化（p=0.08），这表明汞的生物放大不会随季节变化。然而，不同食物链模型之间的 TMS 存在显著差异。与由四个物种组成的食物链（0.26）相比，由碎屑食性和肉食性鱼类组成的食物链（0.20）的 TMS 较低。结果表明，食物链建模会影响 TMS 的结果。
