Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Muelle de Poniente s/n, 07015, Mallorca, Spain.
Fish Ecology Group, Instituto Mediterráneo de Estudios Avanzados (IMEDEA-CSIC/UIB), Mallorca, Spain; Fish Ethology and Welfare Group, Centro de Ciencias do Mar (CCMAR), Faro, Portugal.
Aquat Toxicol. 2021 Feb;231:105737. doi: 10.1016/j.aquatox.2020.105737. Epub 2021 Jan 5.
Increasing global research has identified microplastics (MPs) to be impacting marine organisms. The present work aimed at investigating the physiological and behavioral effects of thirty-six juvenile Sparus aurata exposed to control, virgin and weathered MPs enriched diets during a 21-day period under controlled conditions. Physiological effects were assessed in liver and brain using the following biomarkers: activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRd), the detoxifying enzyme glutathione S-transferase (GST) and malondialdehyde (MDA) as indicative of lipid peroxidation. Individuals were recorded for behavior analysis (i.e. social interactions and feeding behavior). Results revealed an increase in cellular stress from control to weathered fish groups, with the virgin group showing intermediate levels in all quantified biomarkers. Significant differences were found in the liver for all biomarkers except for MDA, suggesting that exposure time to MPs in this experiment is long enough to trigger the activation of antioxidant enzymes but not to produce cell damage by lipid peroxidation. In brain tissue samples, fish from the weathered group presented significantly higher values for CAT and SOD, highlighting its function as primary antioxidants. Regarding behavioral effects, results showed that the two MPs enriched groups were significantly bolder during social interactions and, although no significantly, tended to be more active during feeding. In conclusion, MPs which have been weathered in marine environmental conditions produces a higher physiological response than virgin MPs but also, a physiological response is variable depending on the tissue analyzed. In addition, a short period to MP exposure seems to affect overall social and feeding behavior but, further research is needed to assess long-term effects of MP ingestion and its potential consequences on fish populations.
越来越多的全球研究表明，微塑料（MPs）正在对海洋生物产生影响。本研究旨在研究 36 只幼年金枪鱼（Sparus aurata）在控制条件下暴露于对照、原始和风化 MPs 富集饮食 21 天后的生理和行为影响。使用以下生物标志物评估肝脏和大脑的生理效应：抗氧化酶过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）和谷胱甘肽还原酶（GRd）的活性、解毒酶谷胱甘肽 S-转移酶（GST）和丙二醛（MDA）作为脂质过氧化的指示物。对个体进行行为分析（即社交互动和摄食行为）。结果表明，从对照组到风化组，细胞应激增加，而原始组在所有定量生物标志物中均显示出中间水平。除 MDA 外，在肝脏中发现所有生物标志物均存在显著差异，这表明在本实验中暴露于 MPs 的时间足以引发抗氧化酶的激活，但不足以通过脂质过氧化产生细胞损伤。在脑组织样本中，风化组的鱼CAT 和 SOD 值显著升高，突出了其作为主要抗氧化剂的功能。关于行为效应，结果表明，两个富含 MPs 的组在社交互动中表现出更大的胆量，尽管在摄食过程中没有明显的变化，但表现出更高的活跃度。总之，在海洋环境条件下风化的 MPs 比原始 MPs 产生更高的生理反应，但生理反应也因分析的组织而异。此外，暴露于 MPs 的时间较短似乎会影响整体社交和摄食行为，但需要进一步研究来评估 MP 摄入及其对鱼类种群潜在影响的长期影响。
