Laboratorio de Evaluación de la Salud de los Ecosistemas Acuáticos, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s/n 11340, Miguel Hidalgo, Mexico City, Mexico.
Coordinación Politécnica para la Sustentabilidad, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n Esq. Wilfrido Massieu, 07738, Mexico City, Mexico.
Environ Sci Pollut Res Int. 2020 Aug;27(24):30755-30766. doi: 10.1007/s11356-020-09161-w. Epub 2020 May 30.
Rivers are critical ecosystems for protecting and harboring high biodiversity. Tropical rivers particularly are unique for facing extreme climatic events under the current accelerated disruption from human activities. The Bobos-Nautla river basin is exposed to climatic events and disturbances from anthropogenic impacts that stress aquatic organisms. We assessed the health condition of this river system using a non-conventional biomonitor, Corydalus sp., with a set of early-warning biomarkers including lipid peroxidation levels (LPO) and antioxidant activity, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and the neurotransmitter acetylcholinesterase (AChE) considering their spatial and temporal variations. Biomarkers and water quality parameters were analyzed, and the integrated biomarker response (IBR) was assessed as a stress index. Biomarkers showed no significant spatial differences; however, a high-stress period during the rainy season was detected, evidenced by the highest LPO levels; this period is related to the leaching of allochthonous materials from agricultural and urban zones. The peak IBR value during the rainy season confirmed the seasonality of biomarkers. A slight increase in IBR was recorded in lowlands, seemingly associated with agricultural land and human settlements. A principal component analysis showed nutrient enrichment during the rainy season and depletion during the cold-dry season, together with a peak activity of antioxidant enzymes. These results highlight the importance of climatic events such as the rainy season on the health condition of Corydalus sp., which is highly sensitive to the complex mixtures of pollutants that enter the waterbody during extreme climatic events, promoting oxidative stress. Our results also showed the ability of Corydalus sp. to recover and return to a basal level.
河流是保护和维持高生物多样性的关键生态系统。特别是热带河流，由于当前人类活动的加速干扰，面临着极端气候事件的独特挑战。博博斯-瑙特拉河流域易受到气候事件和人为影响的干扰，这些干扰对水生生物造成压力。我们使用一种非传统的生物监测器 Corydalus sp. 评估了这个河流系统的健康状况，该监测器具有一组早期预警生物标志物，包括脂质过氧化水平 (LPO) 和抗氧化活性、超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GPx) 和神经递质乙酰胆碱酯酶 (AChE)，考虑到它们的时空变化。分析了生物标志物和水质参数，并评估了综合生物标志物响应 (IBR) 作为应激指数。生物标志物没有表现出显著的空间差异；然而，在雨季检测到了一个高压力期，表现为最高的 LPO 水平；这一时期与农业和城市地区的外源物质浸出有关。雨季期间的峰值 IBR 值证实了生物标志物的季节性。在低地记录到 IBR 略有增加，似乎与农业用地和人类住区有关。主成分分析表明，雨季期间存在养分富化，寒冷干旱季节期间存在养分枯竭，同时抗氧化酶的活性达到峰值。这些结果强调了气候事件（如雨季）对 Corydalus sp. 健康状况的重要性，Corydalus sp. 对进入水体的复杂污染物混合物非常敏感，容易受到极端气候事件的影响，导致氧化应激。我们的结果还表明，Corydalus sp. 有恢复和回到基础水平的能力。
