Groupe Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département de Sciences Biologiques, Université de Montréal, Pavillon Marie-Victorin, 90 Vincent d'Indy, Montréal, QC, H2V 2S9, Canada.
Groupe Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département de Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal, QC, H3C 3P8, Canada.
Environ Pollut. 2019 Nov;254(Pt A):112963. doi: 10.1016/j.envpol.2019.112963. Epub 2019 Jul 26.
Whereas early life stages are usually considered as particularly sensitive to both organic and inorganic contaminants, field studies assessing contaminant bioaccumulation in these stages are scarce. Selenium (Se) is thought to counteract Hg toxic effects when it is found at Se:Hg molar ratios above 1. However, the variation of this ratio in key fish tissues of different early life stages is mostly unknown. The present study therefore aimed to assess Hg and Se content in gravid female tissues (gonads, muscle, liver, gut, and brain) and different life stages (egg masses, newly hatched larvae (NHL), larvae and juvenile) of Yellow Perch (YP) in a large fluvial lake (Lake Saint-Pierre, Québec, Canada). Se:Hg molar ratios were measured for each compartment in order to fill associated knowledge gaps. Total Hg (THg) and methylmercury (MeHg) concentration varied between tissue according to the following trend: Muscle > Liver > Gut > Brain > Gonads. During YP early life stages, MeHg values increased according to an ontogenetic pattern (mg/kg dw) (mean ± SEM): Egg masses (0.01 ± 0.002) < NHL (0.015 ± 0.001) < Larvae (0.14 ± 0.01) < Juveniles (0.18 ± 0.01). Se concentrations in different YP tissues showed the following trend (mg/kg dw) (mean ± SEM): Gut (3.6 ± 0.1) > Liver (2.5 ± 0.1) > Gonads (1.92 ± 0.06) > Brain (1.26 ± 0.03) > Muscle (1.23 ± 0.06). In YP early life stages, Se concentrations were highest in NHL (3.0 ± 0.2), and then decreased as follows: Egg masses (2.8 ± 0.1) > Larvae (1.37 ± 0.04) > Juveniles (0.93 ± 0.05). Se:Hg molar ratios varied considerably and were systematically above 1. This is the first study to simultaneously report Hg and Se bioaccumulation through fish life cycle.
虽然早期生命阶段通常被认为对有机和无机污染物特别敏感，但评估这些阶段中污染物生物累积的现场研究却很少。当硒 (Se) 与汞 (Hg) 的摩尔比高于 1 时，人们认为硒可以抵消汞的毒性影响。然而，不同早期生命阶段关键鱼类组织中这种比例的变化大多未知。因此，本研究旨在评估大河流湖泊（加拿大魁北克省圣皮埃尔湖）中怀孕雌性组织（性腺、肌肉、肝脏、肠道和大脑）和不同生命阶段（卵块、刚孵化的幼虫 (NHL)、幼虫和幼鱼）中的 Hg 和 Se 含量。为了填补相关知识空白，测量了每个隔室的 Se:Hg 摩尔比。根据以下趋势，总汞 (THg) 和甲基汞 (MeHg) 浓度在组织之间变化：肌肉 > 肝脏 > 肠道 > 大脑 > 性腺。在 YP 早期生命阶段，MeHg 值根据个体发生模式（mg/kg dw）增加（平均值 ± SEM）：卵块（0.01 ± 0.002）<NHL（0.015 ± 0.001）<幼虫（0.14 ± 0.01）<幼鱼（0.18 ± 0.01）。YP 不同组织中的 Se 浓度表现出以下趋势（mg/kg dw）（平均值 ± SEM）：肠道（3.6 ± 0.1）> 肝脏（2.5 ± 0.1）> 性腺（1.92 ± 0.06）> 大脑（1.26 ± 0.03）> 肌肉（1.23 ± 0.06）。在 YP 早期生命阶段，NHL 中的 Se 浓度最高（3.0 ± 0.2），然后依次降低：卵块（2.8 ± 0.1）> 幼虫（1.37 ± 0.04）> 幼鱼（0.93 ± 0.05）。Se:Hg 摩尔比变化很大，并且系统地高于 1。这是首次同时报告鱼类生命周期中 Hg 和 Se 的生物累积。
